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bsradm

bsradm [options...] [-- [ backend-options...]] {command} {context...}

DESCRIPTION

bsradm 유틸리티는 구성 파일을 기반으로 bsr을 관리하는데 사용됩니다. 이 명령은 커널 모듈을 제어하고 디스크상의 메타 데이터를 조작하는 상위 레벨 명령을 하나 이상의 하위 레벨 명령으로 변환하여 "bsrsetup"및 "bsrmeta"유틸리티로 재지정 합니다. 명령에 따라 하나 이상의 리소스, 장치, 연결 또는 피어 장치에 대해 작동합니다. 리소스는 이름으로 지정하고 all 키워드는 모든 리소스에 대한 지정을 의미 합니다.

다음과 같은 명령 컨텍스트가 정의됩니다.

device

장치. minor 번호로 지정하거나(minor- minornumber, e.g. minor-0) 리소스/볼륨번호(resource/volume)로 지정합니다. 리소스만 지정하면 해당 문맥의 모든 장치에 대해 명령을 반복합니다.

connection

연결. 리소스:연결이름(resource:connection-name)으로 지정합니다. 리소스만 지정하면 해당 문맥의 모든 연결에 대해 명령을 반복합니다.

peer_device

피어 장치. 리소스:연결이름/볼륨번호(resource:connection-name/volume)로 지정합니다. 리소스, 장치, 연결만 지정하면 해당 문맥의 모든 피어 장치에 대해 명령을 반복합니다.

이중 대시 다음의 모든 옵션은 지정된대로 하위 수준 유틸리티로 전달됩니다. 또한, bsradm은 bsrsetup의 대부분의 옵션을 이해하며 이중 대시 없이도 옵션을 전달합니다.

OPTIONS

-d, --dry-run

bsradm -d up resource와 같이 실제로 실행하지 않고 실행할 명령을 표시합니다. 이것은 bsrsetup 및 bsrmeta 사용법을 배우는 유용한 방법이 될 수 있습니다.

-c, --config-file file

대체 구성 파일을 사용할 수 있습니다. 기본적으로 bsradm은 다음 중에서 존재하는 첫 번째 파일을 사용합니다: /etc/bsr-90.conf, ./etc/bsr-84.conf, /etc/bsr-83.conf, /etc/bsr-82.conf, /etc/bsr-08.conf, /etc/bsr.conf.

-t, --config-to-test file

추가 구성 파일을 사용할 수 있습니다. 이 옵션은 dump 및 sh-nop 명령에서만 사용할 수 있습니다.

-s, --bsrsetup file

bsrsetup 프로그램의 전체 경로를 지정합니다. 이 옵션을 생략하면 bsradm이 먼저 같은 경로에서 찾은 다음 PATH 경로를 찾습니다.

-m, --bsrmeta file

bsrmeta 프로그램의 전체 경로를 지정합니다. 이 옵션을 생략하면 bsradm이 먼저 같은 경로에서 찾은 다음 PATH 경로를 찾습니다.

-S, --stacked

bsr에서 사용하지 않는 옵션입니다.

COMMANDS

adjust { resource}

구성 파일과 일치하도록 커널 모듈의 구성을 조정합니다. 그 결과는 모든 리소스를 중지하고 다시 시작할 때('bsradm down all' 다음에 'bsradm up all')와 동일해야 합니다. adjust 명령은 경우에 따라 구성 변경을 잘못 해석 할 수 있습니다. 안전을 위해 실제 명령을 실행하기 전에 명령이 수행 할 작업(--dry-run 옵션 사용)을 확인하십시오.

adjust-with-progress { resource}

adjust 와 동일하지만 명령 진행 과정에 대한 추가 정보를 제공합니다.

apply-al { device}

지정된 장치의 activity log 를 적용합니다.

attach { device}

하위 수준의 장치를 복제 장치로 적재합니다.

connect { connection}

피어에 대한 기존 연결을 활성화 합니다. 연결은 new-peer 명령으로 먼저 작성해야 하며 new-path 명령으로 하나 이상의 경로를 작성해야 합니다.

create-md { device}

장치의 메타 데이터를 초기화 합니다. 이것은 복제 장치를 최초 연결하기 전에 필요합니다.

cstate { connection}

현재의 연결 상태를 표시합니다.

detach { device}

복제 장치의 하위 장치를 분리합니다.

disconnect { connection}

피어 호스트와의 연결을 제거 합니다.

disk-options { device}

적재된 장치의 disk 옵션을 변경합니다.

down { resource}

이 명령을 통해 모든 볼륨과 연결 그리고 리소스 자체를 제거하여 중지 합니다.

dstate { device}

하위 장치의 현재 디스크 상태를 출력합니다.

dump { resource}

구성파일은 파싱하여 stdout 으로 출력합니다.

dump-md { device}

장치의 메타데이터를 텍스트 형식으로 덤프합니다. 비트맵과 액티비트 로그도 포함됩니다.

get-gi { peer_device}

특정 연결의 장치를 위한 생성 식별자(GI)를 출력합니다. 적재된 장치에는 bsrsetup, 적재되지 않은 장치에는 bsrmeta 를 사용합니다.

hidden-commands

명시적으로 문서화되지 않은 모든 명령을 표시합니다.

invalidate { peer_device}

장치의 로컬 데이터를 피어의 데이터로 동기화 합니다.

invalidate-remote { peer_device}

피어 장치의 데이터를 로컬 노드의 장치로 동기화 합니다.

net-options { connection}

기존 연결의 net 옵션을 변경합니다.

new-current-uuid { device}

새로운 current UUID 를 생성합니다.

outdate { device}

하위 장치의 데이터를 outdated 로 지정합니다.

pause-sync { peer_device}

로컬 일시 정지 플래그를 설정하여 로컬 장치와 피어 장치 간의 재 동기화를 중지합니다.

primary { resource}

리소스에서 노드의 역할을 primary로 변경합니다.

resize { device}

모든 노드에서 복제장치의 하위 장치 크기를 조정합니다. 이것은 check-resize 와 resize 하위 레벨 명령을 결합하여 수행합니다.

resource-options { resource}

기존 리소스의 리소스 옵션을 변경합니다.

resume-sync { peer_device}

로컬 동기화 일시 정지 플래그를 지워서 재 동기화가 재개 되도록 합니다.

role { resource}

리소스의 현재 역할을 출력합니다.

secondary { resource}

리소스의 역할을 Secondary 로 변경(강등)합니다. 만약 리소스의 복제 장치가 사용 중 이라면 리눅스에서 이 명령은 실패합니다. 윈도우즈에선 장치 사용 여부와 관계없이 강등합니다.

show-gi { peer_device}

특정 연결에서 장치의 데이터 생성 식별자를 표시합니다. 또한 출력에 대해 부연설명 합니다.

up { resource}

다음의 과정으로 리소스를 기동합니다

  • 모든 볼륨의 activity log 적용: bsrmeta apply-al

  • 리소스 생성: bsrsetup new-resource

  • 복제 장치 생성: bsrsetup new-device, bsrsetup new-minor

  • 하위 장치 적재: bsrsetup attach

  • 모든 피어에 연결: bsrsetup connect

verify { peer_device}

온라인 검증을 시작, 중지, 또는 특정 부분에 대한 검증을 지정할 수 있습니다.

wait-connect {[ device] | [connection] | [resource]}

피어 상의 장치, 연결 상의 모든 장치들, 모든 피어상의 모든 장치들이 확인 될 때까지 기다립니다.

wait-sync {[ device] | [connection] | [resource]}

장치가 연결되고 최종 재 동기화 작업이 완료 될 때까지 기다립니다. 연결 및 리소스 수준에서도 사용할 수 있습니다

wipe-md { device}

장치의 bsr 메타 데이터를 지웁니다.

forget-peer { connection}

메타 데이터에서 연결되지 않은 피어에 대한 참조를 완전히 제거합니다.

bsrsetup

bsrsetup command {argument...} [option...]

DESCRIPTION

The bsrsetup utility serves to configure the bsr kernel module and to show its current configuration. Users usually interact with the bsradm utility, which provides a more high-level interface to bsr than bsrsetup. (See bsradm's --dry-run option to see how bsradm uses bsrsetup.)Some option arguments have a default scale which applies when a plain number is specified (for example Kilo, or 1024 times the numeric value). Such default scales can be overridden by using a suffix (for example, M for Mega). The common suffixes K = 2^10 = 1024, M = 1024 K, and G = 1024 M are supported.

COMMANDS

bsrsetup attach minor lower_dev meta_data_dev meta_data_index,

bsrsetup disk-options minor

The attach command attaches a lower-level device to an existing replicated device. The disk-options command changes the disk options of an attached lower-level device. In either case, the replicated device must have been created with bsrsetup new-minor. 

Both commands refer to the replicated device by its minor number. lower_dev is the name of the lower-level device. meta_data_dev is the name of the device containing the metadata, and may be the same as lower_dev. meta_data_index is either a numeric metadata index, or the keyword internal for internal metadata, or the keyword flexible for variable-size external metadata. Available options:

--al-extents extents bsr automatically maintains a "hot" or "active" disk area likely to be written to again soon based on the recent write activity. The "active" disk area can be written to immediately, while "inactive" disk areas must be "activated" first, which requires a meta-data write. We also refer to this active disk area as the "activity log". The activity log saves meta-data writes, but the whole log must be resynced upon recovery of a failed node. The size of the activity log is a major factor of how long a resync will take and how fast a replicated disk will become consistent after a crash. The activity log consists of a number of 4-Megabyte segments; the al-extents parameter determines how many of those segments can be active at the same time. The default value for al-extents is 1237, with a minimum of 7 and a maximum of 65536. Note that the effective maximum may be smaller, depending on how you created the device meta data, see also bsrmeta(8) The effective maximum is 919 * (available on-disk activity-log ring-buffer area/4kB -1), the default 32kB ring-buffer effects a maximum of 6433 (covers more than 25 GiB of data) We recommend to keep this well within the amount your backend storage and replication link are able to resync inside of about 5 minutes.

--al-updates {yes | no} With this parameter, the activity log can be turned off entirely (see the al-extents parameter). This will speed up writes because fewer meta-data writes will be necessary, but the entire device needs to be resynchronized opon recovery of a failed primary node. The default value for al-updates is yes.

--disk-barrier, --disk-flushes, --disk-drain bsr has three methods of handling the ordering of dependent write requests:

  • disk-barrier Use disk barriers to make sure that requests are written to disk in the right order. Barriers ensure that all requests submitted before a barrier make it to the disk before any requests submitted after the barrier. This is implemented using 'tagged command queuing' on SCSI devices and 'native command queuing' on SATA devices. Only some devices and device stacks support this method. The device mapper (LVM) only supports barriers in some configurations. Note that on systems which do not support disk barriers, enabling this option can lead to data loss or corruption. Until bsr 8.4.1, disk-barrier was turned on if the I/O stack below bsr did support barriers. Kernels since linux-2.6.36 (or 2.6.32 RHEL6) no longer allow to detect if barriers are supported. Since bsr-8.4.2, this option is off by default and needs to be enabled explicitly.

  • disk-flushes Use disk flushes between dependent write requests, also referred to as 'force unit access' by drive vendors. This forces all data to disk. This option is enabled by default.

  • disk-drain Wait for the request queue to "drain" (that is, wait for the requests to finish) before submitting a dependent write request. This method requires that requests are stable on disk when they finish. Before bsr 8.0.9, this was the only method implemented. This option is enabled by default. Do not disable in production environments. 

From these three methods, bsr will use the first that is enabled and supported by the backing storage device. If all three of these options are turned off, bsr will submit write requests without bothering about dependencies. Depending on the I/O stack, write requests can be reordered, and they can be submitted in a different order on different cluster nodes. This can result in data loss or corruption. Therefore, turning off all three methods of controlling write ordering is strongly discouraged. 

A general guideline for configuring write ordering is to use disk barriers or disk flushes when using ordinary disks (or an ordinary disk array) with a volatile write cache. On storage without cache or with a battery backed write cache, disk draining can be a reasonable choice.

--disk-timeout If the lower-level device on which a bsr device stores its data does not finish an I/O request within the defined disk-timeout, bsr treats this as a failure. The lower-level device is detached, and the device's disk state advances to Diskless. If bsr is connected to one or more peers, the failed request is passed on to one of them. This option is dangerous and may lead to kernel panic! "Aborting" requests, or force-detaching the disk, is intended for completely blocked/hung local backing devices which do no longer complete requests at all, not even do error completions. In this situation, usually a hard-reset and failover is the only way out. By "aborting", basically faking a local error-completion, we allow for a more graceful swichover by cleanly migrating services. Still the affected node has to be rebooted "soon". By completing these requests, we allow the upper layers to re-use the associated data pages. If later the local backing device "recovers", and now DMAs some data from disk into the original request pages, in the best case it will just put random data into unused pages; but typically it will corrupt meanwhile completely unrelated data, causing all sorts of damage. Which means delayed successful completion, especially for READ requests, is a reason to panic(). We assume that a delayed *error* completion is OK, though we still will complain noisily about it. The default value of disk-timeout is 0, which stands for an infinite timeout. Timeouts are specified in units of 0.1 seconds. This option is available since bsr 8.3.12.

--md-flushes Enable disk flushes and disk barriers on the meta-data device. This option is enabled by default. See the disk-flushes parameter.

--on-io-error handlerConfigure how bsr reacts to I/O errors on a lower-level device. The following policies are defined:

  • pass_on Change the disk status to Inconsistent, mark the failed block as inconsistent in the bitmap, and retry the I/O operation on a remote cluster node.

  • call-local-io-error Call the local-io-error handler (see the handlers section).

  • detach Detach the lower-level device and continue in diskless mode. 

--read-balancing policyDistribute read requests among cluster nodes as defined by policy. The supported policies are prefer-local (the default), prefer-remote, round-robin, least-pending, when-congested-remote, 32K-striping, 64K-striping, 128K-striping, 256K-striping, 512K-striping and 1M-striping. This option is available since bsr 8.4.1.

resync-after minorDefine that a device should only resynchronize after the specified other device. By default, no order between devices is defined, and all devices will resynchronize in parallel. Depending on the configuration of the lower-level devices, and the available network and disk bandwidth, this can slow down the overall resync process. This option can be used to form a chain or tree of dependencies among devices.

--size size Specify the size of the lower-level device explicitly instead of determining it automatically. The device size must be determined once and is remembered for the lifetime of the device. In order to determine it automatically, all the lower-level devices on all nodes must be attached, and all nodes must be connected. If the size is specified explicitly, this is not necessary. The size value is assumed to be in units of sectors (512 bytes) by default.

--discard-zeroes-if-aligned {yes | no} There are several aspects to discard/trim/unmap support on linux block devices. Even if discard is supported in general, it may fail silently, or may partially ignore discard requests. Devices also announce whether reading from unmapped blocks returns defined data (usually zeroes), or undefined data (possibly old data, possibly garbage). If on different nodes, bsr is backed by devices with differing discard characteristics, discards may lead to data divergence (old data or garbage left over on one backend, zeroes due to unmapped areas on the other backend). Online verify would now potentially report tons of spurious differences. While probably harmless for most use cases (fstrim on a file system), bsr cannot have that. To play safe, we have to disable discard support, if our local backend (on a Primary) does not support "discard_zeroes_data=true". We also have to translate discards to explicit zero-out on the receiving side, unless the receiving side (Secondary) supports "discard_zeroes_data=true", thereby allocating areas what were supposed to be unmapped. There are some devices (notably the LVM/DM thin provisioning) that are capable of discard, but announce discard_zeroes_data=false. In the case of DM-thin, discards aligned to the chunk size will be unmapped, and reading from unmapped sectors will return zeroes. However, unaligned partial head or tail areas of discard requests will be silently ignored. If we now add a helper to explicitly zero-out these unaligned partial areas, while passing on the discard of the aligned full chunks, we effectively achieve discard_zeroes_data=true on such devices. Setting discard-zeroes-if-aligned to yes will allow bsr to use discards, and to announce discard_zeroes_data=true, even on backends that announce discard_zeroes_data=false. Setting discard-zeroes-if-aligned to no will cause bsr to always fall-back to zero-out on the receiving side, and to not even announce discard capabilities on the Primary, if the respective backend announces discard_zeroes_data=false. We used to ignore the discard_zeroes_data setting completely. To not break established and expected behaviour, and suddenly cause fstrim on thin-provisioned LVs to run out-of-space instead of freeing up space, the default value is yes. This option is available since 8.4.7.

--rs-discard-granularity byteWhen rs-discard-granularity is set to a non zero, positive value then bsr tries to do a resync operation in requests of this size. In case such a block contains only zero bytes on the sync source node, the sync target node will issue a discard/trim/unmap command for the area. The value is constrained by the discard granularity of the backing block device. In case rs-discard-granularity is not a multiplier of the discard granularity of the backing block device bsr rounds it up. The feature only gets active if the backing block device reads back zeroes after a discard command. The default value of is 0. This option is available since 8.4.7.

bsrsetup peer-device-options resource peer_node_id volume

These are options that affect the peer's device.

--c-delay-target delay_target, 

--c-fill-target fill_target, 

--c-max-rate max_rate, 

--c-plan-ahead plan_time Dynamically control the resync speed. This mechanism is enabled by setting the c-plan-ahead parameter to a positive value. The goal is to either fill the buffers along the data path with a defined amount of data if c-fill-target is defined, or to have a defined delay along the path if c-delay-target is defined. The maximum bandwidth is limited by the c-max-rate parameter. The c-plan-ahead parameter defines how fast bsr adapts to changes in the resync speed. It should be set to five times the network round-trip time or more. Common values for c-fill-target for "normal" data paths range from 4K to 100K. If bsr-proxy is used, it is advised to use c-delay-target instead of c-fill-target. The c-delay-target parameter is used if the c-fill-target parameter is undefined or set to 0. The c-delay-target parameter should be set to five times the network round-trip time or more. The c-max-rate option should be set to either the bandwidth available between the bsr-hosts and the machines hosting bsr-proxy, or to the available disk bandwidth. The default values of these parameters are: c-plan-ahead = 20 (in units of 0.1 seconds), c-fill-target = 0 (in units of sectors), c-delay-target = 1 (in units of 0.1 seconds), and c-max-rate = 102400 (in units of KiB/s). Dynamic resync speed control is available since bsr 8.3.9.

--c-min-rate min_rate A node which is primary and sync-source has to schedule application I/O requests and resync I/O requests. The c-min-rate parameter limits how much bandwidth is available for resync I/O; the remaining bandwidth is used for application I/O. A c-min-rate value of 0 means that there is no limit on the resync I/O bandwidth. This can slow down application I/O significantly. Use a value of 1 (1 KiB/s) for the lowest possible resync rate. The default value of c-min-rate is 4096, in units of KiB/s.

--resync-rate rate Define how much bandwidth bsr may use for resynchronizing. bsr allows "normal" application I/O even during a resync. If the resync takes up too much bandwidth, application I/O can become very slow. This parameter allows to avoid that. Please note this is option only works when the dynamic resync controller is disabled.

bsrsetup check-resize minor

Remember the current size of the lower-level device of the specified replicated device. Used by bsradm. The size information is stored in file /var/lib/bsr/bsr-minor- minor.lkbd.

bsrsetup new-peer resource peer_node_id,

bsrsetup net-options resource peer_node_id

The new-peer command creates a connection within a resource. The resource must have been created with bsrsetup new-resource. The net-options command changes the network options of an existing connection. Before a connection can be activated with the connect command, at least one path need to added with the new-path command. Available options:

--after-sb-0pri policy Define how to react if a split-brain scenario is detected and none of the two nodes is in primary role. (We detect split-brain scenarios when two nodes connect; split-brain decisions are always between two nodes.) The defined policies are:

  • disconnect No automatic resynchronization; simply disconnect.

  • discard-younger-primary, 

  • discard-older-primary Resynchronize from the node which became primary first ( discard-younger-primary) or last (discard-older-primary). If both nodes became primary independently, the discard-least-changes policy is used.

  • discard-zero-changes If only one of the nodes wrote data since the split brain situation was detected, resynchronize from this node to the other. If both nodes wrote data, disconnect.

  • discard-least-changes Resynchronize from the node with more modified blocks.

  • discard-node-nodename Always resynchronize to the named node.

--after-sb-1pri policy Define how to react if a split-brain scenario is detected, with one node in primary role and one node in secondary role. (We detect split-brain scenarios when two nodes connect, so split-brain decisions are always among two nodes.) The defined policies are:

  • disconnect No automatic resynchronization, simply disconnect.

  • consensus Discard the data on the secondary node if the after-sb-0pri algorithm would also discard the data on the secondary node. Otherwise, disconnect.

  • violently-as0p Always take the decision of the after-sb-0pri algorithm, even if it causes an erratic change of the primary's view of the data. This is only useful if a single-node file system (i.e., not OCFS2 or GFS) with the allow-two-primaries flag is used. This option can cause the primary node to crash, and should not be used.

  • discard-secondary Discard the data on the secondary node.

  • call-pri-lost-after-sb Always take the decision of the after-sb-0pri algorithm. If the decision is to discard the data on the primary node, call the pri-lost-after-sb handler on the primary node.

--after-sb-2pri policy Define how to react if a split-brain scenario is detected and both nodes are in primary role. (We detect split-brain scenarios when two nodes connect, so split-brain decisions are always among two nodes.) The defined policies are:

  • disconnect No automatic resynchronization, simply disconnect.

  • violently-as0p See the violently-as0p policy for after-sb-1pri.

  • call-pri-lost-after-sb Call the pri-lost-after-sb helper program on one of the machines unless that machine can demote to secondary. The helper program is expected to reboot the machine, which brings the node into a secondary role. Which machine runs the helper program is determined by the after-sb-0pri strategy.

--allow-two-primaries The most common way to configure bsr devices is to allow only one node to be primary (and thus writable) at a time. In some scenarios it is preferable to allow two nodes to be primary at once; a mechanism outside of bsr then must make sure that writes to the shared, replicated device happen in a coordinated way. This can be done with a shared-storage cluster file system like OCFS2 and GFS, or with virtual machine images and a virtual machine manager that can migrate virtual machines between physical machines. The allow-two-primaries parameter tells bsr to allow two nodes to be primary at the same time. Never enable this option when using a non-distributed file system; otherwise, data corruption and node crashes will result!

--always-asbp Normally the automatic after-split-brain policies are only used if current states of the UUIDs do not indicate the presence of a third node. With this option you request that the automatic after-split-brain policies are used as long as the data sets of the nodes are somehow related. This might cause a full sync, if the UUIDs indicate the presence of a third node. (Or double faults led to strange UUID sets.)

--connect-int time As soon as a connection between two nodes is configured with bsrsetup connect, bsr immediately tries to establish the connection. If this fails, bsr waits for connect-int seconds and then repeats. The default value of connect-int is 10 seconds.

--cram-hmac-alg hash-algorithm Configure the hash-based message authentication code (HMAC) or secure hash algorithm to use for peer authentication. The kernel supports a number of different algorithms, some of which may be loadable as kernel modules. See the shash algorithms listed in /proc/crypto. By default, cram-hmac-alg is unset. Peer authentication also requires a shared-secret to be configured.

--csums-alg hash-algorithm Normally, when two nodes resynchronize, the sync target requests a piece of out-of-sync data from the sync source, and the sync source sends the data. With many usage patterns, a significant number of those blocks will actually be identical. When a csums-alg algorithm is specified, when requesting a piece of out-of-sync data, the sync target also sends along a hash of the data it currently has. The sync source compares this hash with its own version of the data. It sends the sync target the new data if the hashes differ, and tells it that the data are the same otherwise. This reduces the network bandwidth required, at the cost of higher cpu utilization and possibly increased I/O on the sync target. The csums-alg can be set to one of the secure hash algorithms supported by the kernel; see the shash algorithms listed in /proc/crypto. By default, csums-alg is unset.

--csums-after-crash-only Enabling this option (and csums-alg, above) makes it possible to use the checksum based resync only for the first resync after primary crash, but not for later "network hickups". In most cases, block that are marked as need-to-be-resynced are in fact changed, so calculating checksums, and both reading and writing the blocks on the resync target is all effective overhead. The advantage of checksum based resync is mostly after primary crash recovery, where the recovery marked larger areas (those covered by the activity log) as need-to-be-resynced, just in case. Introduced in 8.4.5.

--data-integrity-alg alg bsr normally relies on the data integrity checks built into the TCP/IP protocol, but if a data integrity algorithm is configured, it will additionally use this algorithm to make sure that the data received over the network match what the sender has sent. If a data integrity error is detected, bsr will close the network connection and reconnect, which will trigger a resync. The data-integrity-alg can be set to one of the secure hash algorithms supported by the kernel; see the shash algorithms listed in /proc/crypto. By default, this mechanism is turned off. Because of the CPU overhead involved, we recommend not to use this option in production environments. Also see the notes on data integrity below.

--fencing fencing_policy Fencing is a preventive measure to avoid situations where both nodes are primary and disconnected. This is also known as a split-brain situation. bsr supports the following fencing policies:

  • dont-care No fencing actions are taken. This is the default policy.

  • resource-only If a node becomes a disconnected primary, it tries to fence the peer. This is done by calling the fence-peer handler. The handler is supposed to reach the peer over an alternative communication path and call ' bsradm outdate minor' there.

  • resource-and-stonith If a node becomes a disconnected primary, it freezes all its IO operations and calls its fence-peer handler. The fence-peer handler is supposed to reach the peer over an alternative communication path and call ' bsradm outdate minor' there. In case it cannot do that, it should stonith the peer. IO is resumed as soon as the situation is resolved. In case the fence-peer handler fails, I/O can be resumed manually with ' bsradm resume-io'.

--ko-count number If a secondary node fails to complete a write request in ko-count times the timeout parameter, it is excluded from the cluster. The primary node then sets the connection to this secondary node to Standalone. To disable this feature, you should explicitly set it to 0; defaults may change between versions.

--max-buffers number Limits the memory usage per bsr minor device on the receiving side, or for internal buffers during resync or online-verify. Unit is PAGE_SIZE, which is 4 KiB on most systems. The minimum possible setting is hard coded to 32 (=128 KiB). These buffers are used to hold data blocks while they are written to/read from disk. To avoid possible distributed deadlocks on congestion, this setting is used as a throttle threshold rather than a hard limit. Once more than max-buffers pages are in use, further allocation from this pool is throttled. You want to increase max-buffers if you cannot saturate the IO backend on the receiving side.

--max-epoch-size number Define the maximum number of write requests bsr may issue before issuing a write barrier. The default value is 2048, with a minimum of 1 and a maximum of 20000. Setting this parameter to a value below 10 is likely to decrease performance.

--on-congestion policy, 

--congestion-fill threshold, 

--congestion-extents threshold By default, bsr blocks when the TCP send queue is full. This prevents applications from generating further write requests until more buffer space becomes available again. When bsr is used together with bsr-proxy, it can be better to use the pull-ahead on-congestion policy, which can switch bsr into ahead/behind mode before the send queue is full. bsr then records the differences between itself and the peer in its bitmap, but it no longer replicates them to the peer. When enough buffer space becomes available again, the node resynchronizes with the peer and switches back to normal replication. This has the advantage of not blocking application I/O even when the queues fill up, and the disadvantage that peer nodes can fall behind much further. Also, while resynchronizing, peer nodes will become inconsistent. The available congestion policies are block (the default) and pull-ahead. The congestion-fill parameter defines how much data is allowed to be "in flight" in this connection. The default value is 0, which disables this mechanism of congestion control, with a maximum of 10 GiBytes. The congestion-extents parameter defines how many bitmap extents may be active before switching into ahead/behind mode, with the same default and limits as the al-extents parameter. The congestion-extents parameter is effective only when set to a value smaller than al-extents. Ahead/behind mode is available since bsr 8.3.10.

--ping-int interval When the TCP/IP connection to a peer is idle for more than ping-int seconds, bsr will send a keep-alive packet to make sure that a failed peer or network connection is detected reasonably soon. The default value is 10 seconds, with a minimum of 1 and a maximum of 120 seconds. The unit is seconds.

--ping-timeout timeout Define the timeout for replies to keep-alive packets. If the peer does not reply within ping-timeout, bsr will close and try to reestablish the connection. The default value is 0.5 seconds, with a minimum of 0.1 seconds and a maximum of 3 seconds. The unit is tenths of a second.

--socket-check-timeout timeout In setups involving a bsr-proxy and connections that experience a lot of buffer-bloat it might be necessary to set ping-timeout to an unusual high value. By default bsruses the same value to wait if a newly established TCP-connection is stable. Since the bsr-proxy is usually located in the same data center such a long wait time may hinder bsr's connect process. In such setups socket-check-timeout should be set to at least to the round trip time between bsr and bsr-proxy. I.e. in most cases to 1. The default unit is tenths of a second, the default value is 0 (which causes bsr to use the value of ping-timeout instead). Introduced in 8.4.5.

--protocol name Use the specified protocol on this connection. The supported protocols are:

  • A Writes to the bsr device complete as soon as they have reached the local disk and the TCP/IP send buffer.

  • B Writes to the bsr device complete as soon as they have reached the local disk, and all peers have acknowledged the receipt of the write requests.

  • C Writes to the bsr device complete as soon as they have reached the local and all remote disks. 

--rcvbuf-size size Configure the size of the TCP/IP receive buffer. A value of 0 (the default) causes the buffer size to adjust dynamically. This parameter usually does not need to be set, but it can be set to a value up to 10 MiB. The default unit is bytes.

--rr-conflict policy This option helps to solve the cases when the outcome of the resync decision is incompatible with the current role assignment in the cluster. The defined policies are:

  • disconnect No automatic resynchronization, simply disconnect.

  • violently Resync to the primary node is allowed, violating the assumption that data on a block device are stable for one of the nodes. Do not use this option, it is dangerous.

  • call-pri-lost Call the pri-lost handler on one of the machines. The handler is expected to reboot the machine, which puts it into secondary role.

--shared-secret secret Configure the shared secret used for peer authentication. The secret is a string of up to 64 characters. Peer authentication also requires the cram-hmac-alg parameter to be set.

--sndbuf-size size Configure the size of the TCP/IP send buffer. Since bsr 8.0.13 / 8.2.7, a value of 0 (the default) causes the buffer size to adjust dynamically. Values below 32 KiB are harmful to the throughput on this connection. Large buffer sizes can be useful especially when protocol A is used over high-latency networks; the maximum value supported is 10 MiB.

--tcp-cork By default, bsr uses the TCP_CORK socket option to prevent the kernel from sending partial messages; this results in fewer and bigger packets on the network. Some network stacks can perform worse with this optimization. On these, the tcp-cork parameter can be used to turn this optimization off.

--timeout time Define the timeout for replies over the network: if a peer node does not send an expected reply within the specified timeout, it is considered dead and the TCP/IP connection is closed. The timeout value must be lower than connect-int and lower than ping-int. The default is 6 seconds; the value is specified in tenths of a second.

--use-rle Each replicated device on a cluster node has a separate bitmap for each of its peer devices. The bitmaps are used for tracking the differences between the local and peer device: depending on the cluster state, a disk range can be marked as different from the peer in the device's bitmap, in the peer device's bitmap, or in both bitmaps. When two cluster nodes connect, they exchange each other's bitmaps, and they each compute the union of the local and peer bitmap to determine the overall differences. Bitmaps of very large devices are also relatively large, but they usually compress very well using run-length encoding. This can save time and bandwidth for the bitmap transfers. The use-rle parameter determines if run-length encoding should be used. It is on by default since bsr 8.4.0.

--verify-alg hash-algorithm Online verification (bsradm verify) computes and compares checksums of disk blocks (i.e., hash values) in order to detect if they differ. The verify-alg parameter determines which algorithm to use for these checksums. It must be set to one of the secure hash algorithms supported by the kernel before online verify can be used; see the shash algorithms listed in /proc/crypto. We recommend to schedule online verifications regularly during low-load periods, for example once a month. Also see the notes on data integrity below.

bsrsetup new-path resource peer_node_id local-addr remote-addr

The new-path command creates a path within a connection. The connection must have been created with bsrsetup new-peer. Local_addr and remote_addr refer to the local and remote protocol, network address, and port in the format [ address-family:] address[:port]. The address families ipv4, ipv6, ssocks (Dolphin Interconnect Solutions' "super sockets"), sdp (Infiniband Sockets Direct Protocol), and sci are supported ( sci is an alias for ssocks). If no address family is specified, ipv4 is assumed. For all address families except ipv6, the address uses IPv4 address notation (for example, 1.2.3.4). For ipv6, the address is enclosed in brackets and uses IPv6 address notation (for example, [fd01:2345:6789:abcd::1]). The port defaults to 7788.

bsrsetup connect resource peer_node_id

The connect command activates a connection. That means that the bsr driver will bind and listen on all local addresses of the connection-'s paths. It will begin to try to establish one or more paths of the connection. Available options:

--tentative Only determine if a connection to the peer can be established and if a resync is necessary (and in which direction) without actually establishing the connection or starting the resync. Check the system log to see what bsr would do without the --tentative option.

--discard-my-data Discard the local data and resynchronize with the peer that has the most up-to-data data. Use this option to manually recover from a split-brain situation.

bsrsetup del-peer resource peer_node_id

The del-peer command removes a connection from a resource.

bsrsetup del-path resource peer_node_id local-addr remote-addr

The del-path command removes a path from a connection. Please note that it fails if the path is necessary to keep a connected connection in tact. In order to remove all paths, disconnect the connection first.

bsrsetup cstate resource peer_node_id

Show the current state of a connection. The connection is identified by the node-id of the peer; see the bsrsetup connect command.

bsrsetup del-minor minor

Remove a replicated device. No lower-level device may be attached; see bsrsetup detach.

bsrsetup del-resource resource

Remove a resource. All volumes and connections must be removed first ( bsrsetup del-minor, bsrsetup disconnect). Alternatively, bsrsetup down can be used to remove a resource together with all its volumes and connections.

bsrsetup detach minor

Detach the lower-level device of a replicated device. Available options:

--force Force the detach and return immediately. This puts the lower-level device into failed state until all pending I/O has completed, and then detaches the device. Any I/O not yet submitted to the lower-level device (for example, because I/O on the device was suspended) is assumed to have failed. 

bsrsetup disconnect resource peer_node_id

Remove a connection to a peer host. The connection is identified by the node-id of the peer; see the bsrsetup connect command.

bsrsetup down {resource | all}

Take a resource down by removing all volumes, connections, and the resource itself.

bsrsetup dstate minor

Show the current disk state of a lower-level device.

bsrsetup events2 {resource | all}

Show the current state of all configured bsr objects, followed by all changes to the state. The output format is meant to be human as well as machine readable. The line starts with a word that indicates the kind of event: exists for an existing object; create, destroy, and change if an object is created, destroyed, or changed; or call or response if an event handler is called or it returns. The second word indicates the object the event applies to: resource, device, connection, peer-device, helper, or a dash (-) to indicate that the current state has been dumped completely. The remaining words identify the object and describe the state that he object is in. Available options:

--now Terminate after reporting the current state. The default is to continuously listen and report state changes.

--statistics Include statistics in the output. 

bsrsetup get-gi resource peer_node_id volume

Show the data generation identifiers for a device on a particular connection. The device is identified by its volume number. The connection is identified by its endpoints; see the bsrsetup connect command. The output consists of the current UUID, bitmap UUID, and the first two history UUIDS, folowed by a set of flags. The current UUID and history UUIDs are device specific; the bitmap UUID and flags are peer device specific. This command only shows the first two history UUIDs. Internally, bsr maintains one history UUID for each possible peer device.

bsrsetup invalidate minor

Replace the local data of a device with that of a peer. All the local data will be marked out-of-sync, and a resync with the specified peer device will be initialted.

bsrsetup invalidate-remote resource peer_node_id volume

Replace a peer device's data of a resource with the local data. The peer device's data will be marked out-of-sync, and a resync from the local node to the specified peer will be initiated.

bsrsetup new-current-uuid minor

Generate a new current UUID and rotates all other UUID values. This has at least two use cases, namely to skip the initial sync, and to reduce network bandwidth when starting in a single node configuration and then later (re-)integrating a remote site. Available option:

--clear-bitmap Clears the sync bitmap in addition to generating a new current UUID. This can be used to skip the initial sync, if you want to start from scratch. This use-case does only work on "Just Created" meta data. 

bsrsetup new-minor resource minor volume

Create a new replicated device within a resource. The command creates a block device inode for the replicated device (by default, /dev/bsr minor). The volume number identifies the device within the resource.

bsrsetup new-resource resource node_id,

bsrsetup resource-options resource

The new-resource command creates a new resource. The resource-options command changes the resource options of an existing resource. Available options:

--auto-promote bool-value A resource must be promoted to primary role before any of its devices can be mounted or opened for writing. Before bsr 9, this could only be done explicitly ("bsradm primary"). Since bsr 9, the auto-promote parameter allows to automatically promote a resource to primary role when one of its devices is mounted or opened for writing. As soon as all devices are unmounted or closed with no more remaining users, the role of the resource changes back to secondary. Automatic promotion only succeeds if the cluster state allows it (that is, if an explicit bsradm primary command would succeed). Otherwise, mounting or opening the device fails as it already did before bsr 9: the mount(2) system call fails with errno set to EROFS (Read-only file system); the open(2) system call fails with errno set to EMEDIUMTYPE (wrong medium type). Irrespective of the auto-promote parameter, if a device is promoted explicitly ( bsradm primary), it also needs to be demoted explicitly (bsradm secondary). The auto-promote parameter is available since bsr 9.0.0, and defaults to yes.

--cpu-mask cpu-mask Set the cpu affinity mask for bsr kernel threads. The cpu mask is specified as a hexadecimal number. The default value is 0, which lets the scheduler decide which kernel threads run on which CPUs. CPU numbers in cpu-mask which do not exist in the system are ignored.

--on-no-data-accessible policy Determine how to deal with I/O requests when the requested data is not available locally or remotely (for example, when all disks have failed). The defined policies are:

  • io-error System calls fail with errno set to EIO.

  • suspend-io The resource suspends I/O. I/O can be resumed by (re)attaching the lower-level device, by connecting to a peer which has access to the data, or by forcing bsr to resume I/O with bsradm resume-io res. When no data is available, forcing I/O to resume will result in the same behavior as the io-error policy. This setting is available since bsr 8.3.9; the default policy is io-error.

--peer-ack-window value On each node and for each device, bsr maintains a bitmap of the differences between the local and remote data for each peer device. For example, in a three-node setup (nodes A, B, C) each with a single device, every node maintains one bitmap for each of its peers. When nodes receive write requests, they know how to update the bitmaps for the writing node, but not how to update the bitmaps between themselves. In this example, when a write request propagates from node A to B and C, nodes B and C know that they have the same data as node A, but not whether or not they both have the same data. As a remedy, the writing node occasionally sends peer-ack packets to its peers which tell them which state they are in relative to each other. The peer-ack-window parameter specifies how much data a primary node may send before sending a peer-ack packet. A low value causes increased network traffic; a high value causes less network traffic but higher memory consumption on secondary nodes and higher resync times between the secondary nodes after primary node failures. (Note: peer-ack packets may be sent due to other reasons as well, e.g. membership changes or expiry of the peer-ack-delay timer.) The default value for peer-ack-window is 2 MiB, the default unit is sectors. This option is available since 9.0.0.

--peer-ack-delay expiry-time If after the last finished write request no new write request gets issued for expiry-time, then a peer-ack packet is sent. If a new write request is issued before the timer expires, the timer gets reset to expiry-time. (Note: peer-ack packets may be sent due to other reasons as well, e.g. membership changes or the peer-ack-window option.) This parameter may influence resync behavior on remote nodes. Peer nodes need to wait until they receive an peer-ack for releasing a lock on an AL-extent. Resync operations between peers may need to wait for for these locks. The default value for peer-ack-delay is 100 milliseconds, the default unit is milliseconds. This option is available since 9.0.0. 

bsrsetup outdate minor

Mark the data on a lower-level device as outdated. This is used for fencing, and prevents the resource the device is part of from becoming primary in the future. See the --fencing disk option.

bsrsetup pause-sync resource peer_node_id volume

Stop resynchronizing between a local and a peer device by setting the local pause flag. The resync can only resume if the pause flags on both sides of a connection are cleared.

bsrsetup primary resource

Change the role of a node in a resource to primary. This allows the replicated devices in this resource to be mounted or opened for writing. Available options:

--overwrite-data-of-peer This option is an alias for the --force option.

--force Force the resource to become primary even if some devices are not guaranteed to have up-to-date data. This option is used to turn one of the nodes in a newly created cluster into the primary node, or when manually recovering from a disaster. Note that this can lead to split-brain scenarios. Also, when forcefully turning an inconsistent device into an up-to-date device, it is highly recommended to use any integrity checks available (such as a filesystem check) to make sure that the device can at least be used without crashing the system. Note that bsr usually only allows one node in a cluster to be in primary role at any time; this allows bsr to coordinate access to the devices in a resource across nodes. The --allow-two-primaries network option changes this; in that case, a mechanism outside of bsr needs to coordinate device access.

bsrsetup resize minor

Reexamine the size of the lower-level devices of a replicated device on all nodes. This command is called after the lower-level devices on all nodes have been grown to adjust the size of the replicated device. Available options:

--assume-peer-has-space Resize the device even if some of the peer devices are not connected at the moment. bsr will try to resize the peer devices when they next connect. It will refuse to connect to a peer device which is too small.--assume-cleanDo not resynchronize the added disk space; instead, assume that it is identical on all nodes. This option can be used when the disk space is uninitialized and differences do not matter, or when it is known to be identical on all nodes. See the bsrsetup verify command.

--size val This option can be used to online shrink the usable size of a bsr device. It's the users responsibility to make sure that a file system on the device is not truncated by that operation.

--al-stripes val These options may be used to change the layout of the activity log online. In case of internal meta data this may invovle shrinking the user visible size at the same time (unsing the --size) or increasing the avalable space on the backing devices. 

bsrsetup resume-io minor

Resume I/O on a replicated device. See the --fencing net option.

bsrsetup resume-sync resource peer_node_id volume

Allow resynchronization to resume by clearing the local sync pause flag.

bsrsetup role resource

Show the current role of a resource.

bsrsetup secondary resource

Change the role of a node in a resource to secondary. This command fails if the replicated device is in use.

bsrsetup show {resource | all}

Show the current configuration of a resource, or of all resources. Available options:

--show-defaults Show all configuration parameters, even the ones with default values. Normally, parameters with default values are not shown. 

bsrsetup show-gi resource peer_node_id volume

Show the data generation identifiers for a device on a particular connection. In addition, explain the output. The output otherwise is the same as in the bsrsetup get-gi command.

bsrsetup state

This is an alias for bsrsetup role. Deprecated.

bsrsetup status {resource | all}

Show the status of a resource, or of all resources. The output consists of one paragraph for each configured resource. Each paragraph contains one line for each resource, followed by one line for each device, and one line for each connection. The device and connection lines are indented. The connection lines are followed by one line for each peer device; these lines are indented against the connection line. Long lines are wrapped around at terminal width, and indented to indicate how the lines belongs together. Available options:

--verbose Include more information in the output even when it is likely redundant or irrelevant.

--statistics Include data transfer statistics in the output.

--color={always | auto | never} Colorize the output. With --color=auto, bsrsetup emits color codes only when standard output is connected to a terminal. 

For example, the non-verbose output for a resource with only one connection and only one volume could look like this: 

bsr0 role:Primary
  disk:UpToDate
  host2.example.com role:Secondary
    disk:UpToDate

With the --verbose option, the same resource could be reported as: 

bsr0 node-id:1 role:Primary suspended:no
  volume:0 minor:1 disk:UpToDate blocked:no
  host2.example.com local:ipv4:192.168.123.4:7788
      peer:ipv4:192.168.123.2:7788 node-id:0 connection:WFReportParams
      role:Secondary congested:no
    volume:0 replication:Connected disk:UpToDate resync-suspended:no

bsrsetup suspend-io minor

Suspend I/O on a replicated device. It is not usually necessary to use this command.

bsrsetup verify resource peer_node_id volume

Start online verification, change which part of the device will be verified, or stop online verification. The command requires the specified peer to be connected. Online verification compares each disk block on the local and peer node. Blocks which differ between the nodes are marked as out-of-sync, but they are not automatically brought back into sync. To bring them into sync, the resource must be disconnected and reconnected. Progress can be monitored in the output of bsrsetup status --statistics. Available options:

--start position Define where online verification should start. This parameter is ignored if online verification is already in progress. If the start parameter is not specified, online verification will continue where it was interrupted (if the connection to the peer was lost while verifying), after the previous stop sector (if the previous online verification has finished), or at the beginning of the device (if the end of the device was reached, or online verify has not run before). The position on disk is specified in disk sectors (512 bytes) by default.

--stop position Define where online verification should stop. If online verification is already in progress, the stop position of the active online verification process is changed. Use this to stop online verification. The position on disk is specified in disk sectors (512 bytes) by default. Also see the notes on data integrity in the bsr.conf(5) manual page.

bsrsetup wait-connect-volume resource peer_node_id volume,

bsrsetup wait-connect-connection resource peer_node_id,

bsrsetup wait-connect-resource resource,

bsrsetup wait-sync-volume resource peer_node_id volume,

bsrsetup wait-sync-connection resource peer_node_id,

bsrsetup wait-sync-resource resource

The wait-connect-* commands waits until a device on a peer is visible. The wait-sync-* commands waits until a device on a peer is up to date. Available options for both commands:

--degr-wfc-timeout timeout Define how long to wait until all peers are connected in case the cluster consisted of a single node only when the system went down. This parameter is usually set to a value smaller than wfc-timeout. The assumption here is that peers which were unreachable before a reboot are less likely to be reachable after the reboot, so waiting is less likely to help. The timeout is specified in seconds. The default value is 0, which stands for an infinite timeout. Also see the wfc-timeout parameter.

--outdated-wfc-timeout timeout Define how long to wait until all peers are connected if all peers were outdated when the system went down. This parameter is usually set to a value smaller than wfc-timeout. The assumption here is that an outdated peer cannot have become primary in the meantime, so we don't need to wait for it as long as for a node which was alive before. The timeout is specified in seconds. The default value is 0, which stands for an infinite timeout. Also see the wfc-timeout parameter.

--wait-after-sb This parameter causes bsr to continue waiting in the init script even when a split-brain situation has been detected, and the nodes therefore refuse to connect to each other.

--wfc-timeout timeout Define how long the init script waits until all peers are connected. This can be useful in combination with a cluster manager which cannot manage bsr resources: when the cluster manager starts, the bsr resources will already be up and running. With a more capable cluster manager such as Pacemaker, it makes more sense to let the cluster manager control bsr resources. The timeout is specified in seconds. The default value is 0, which stands for an infinite timeout. Also see the degr-wfc-timeout parameter. 

bsrsetup forget-peer resource peer_node_id

The forget-peer command removes all traces of a peer node from the meta-data. It frees a bitmap slot in the meta-data and make it avalable for futher bitmap slot allocation in case a so-far never seen node connects. The connection must be taken down before this command may be used. In case the peer re-connects at a later point a bit-map based resync will be turned into a full-sync.

bsrmeta

bsrmeta [--force] [--ignore-sanity-checks] { device} {v06 minor | v07  meta_dev index | v08 meta_dev index | v09  meta_dev index} { command} [cmd args...]

DESCRIPTION

The bsrmeta utility is used for creating, displaying, and modifying bsr's on-disk metadata. Users usually interact with the bsradm utility, which provides a more high-level interface to bsr than bsrmeta. (See bsradm's --dry-run option to see how bsradm uses bsrmeta.)This utility can only be used on devices which are not currently in use by the kernel.The first argument ( device) specifies the bsr device associated with a volume, or “-” if no device is associated with that volume. If the bsr device is specified, the bsrmeta utility makes sure that the bsr device does not currently have a volume attached to prevent meta-data of an active volume from being destroyed.The second argument specifies the metadata version to use (v06, v07, v08, v09). In most metadata versions, the third argument ( meta_dev) specifies the device which contains the metadata; this argument can be the same as device. The fourth argument ( index) can be one of the keywords internal (for internal metadata), flex-internal (in v07 for variable-sized metadata; v07 otherwise defaults to fixed-size internal metadata), flex-external (for variable-sized external metadata), or a numeric matadata index (for fixed-size external metadata). See the meta-disk parameter in bsr.conf(5).

OPTIONS

--force

Assume yes as the answer to all questions bsrmeta would ask.

--ignore-sanity-checks

Normally, bsrmeta performs some sanity checks before writing to the metadata device: for example, if the device appears to contain a file system, it refuses to destroy the file system by writing into it. Use this option to ignore these checks.

COMMANDS

create-md [--peer-max-bio-size=val] (metadata versions v06, v07, and v08),

create-md {number-of-bitmap-slots} [--peer-max-bio-size=val] [ --al-stripes=val] [--al-stripe-size-kB= val] (metadata version v09)

Initialize the metadata. This is necessary before a bsr resource can be attached. If bsrmeta finds an older version of bsr metadata on the device, it asks if the format should be converted. When bsradm calls bsrmeta's create-md command for a device, it sets the number-of-bitmap-slots argument to the number of peers in the resource. To reserve additional bitmap slots (which allows to add more peers in the future), call bsrmeta directly instead. When a device is used before being connected to its peers the first time, bsr assumes that peers can only handle 4 KiB requests by default. The --peer-max-bio-size option allows to set more optimistic values; use this if the versions of bsr that this device will connect to are known. bsr supports a maximum bio size of 32 KiB since version 8.3.8, of 128 KiB since version 8.3.9, and of 1 MiB since version 8.4.0. If you want to use more than 6433 activity log extents, or live on top of a spriped RAID, you may specify the number of stripes ( --al-stripes, default 1), and the stripe size ( --al-stripe-size-kB, default 32). To just use a larger linear on-disk ring-buffer, leave the number of stripes at 1, and increase the size only: 

  • bsrmeta 0 v08 /dev/vg23/lv42 internal create-md --al-stripe-size 1M To avoid a single "spindle" from becoming a bottleneck, increase the number of stripes, to achieve an interleaved layout of the on-disk activity-log transactions. What you give as "stripe-size" should be what is a.k.a. "chunk size" or "granularity" or "strip unit": the minimum skip to the next "spindle". 

  • bsrmeta 0 v08 /dev/vg23/lv42 internal create-md --al-stripes 7 --al-stripe-size 64

get-gi [--node-id=id]

Show the data generation identifiers for a device on a particular connection. bsr version 9.0.0 and beyond support multiple peers; use the node-id option to define which peer's data generation identifiers to show.

show-gi [--node-id=id]

Similar to get-gi, but with explanatory information.

dump-md

Dump the metadata of a device in text form, including the bitmap and activity log.

outdate

Mark the data on a lower-level device as outdated. See bsrsetup(8) for details.

dstate

Show the current disk state of a lower-level device.

check-resize

Examine the device size of a lower-level device and its last known device size (saved in /var/lib/bsr/bsr-minor-minor.lkbd by bsrsetup check-resize). For internal metadata, if the size of the lower-level device has changed and the metadata can be found at the previous position, move the metadata to the new position at the end of the block device.

apply-al

Apply the activity log of the specified device. This is necessary before the device can be attached by the kernel again.

EXPERT COMMANDS

The bsrmeta utility can be used to fine tune metdata. Please note that this can lead to destroyed metadata or even silent data corruption; use with great care only.

set-gi gi [--node-id=id] 

Set the generation identifiers. The gi argument is a generation counter for the v06 and v07 formats, and a set of UUIDs for v08 and beyond. Accepts the same syntax as in the get-gi output. bsr version 9.0.0 and beyond support multiple peers; use the --node-id option to define which peer's data generation identifiers to set.

restore-md dump_file

Replace the metadata on the device with the contents of dump_file. The dump file format is defined by the output of the dump-md command.

bsrcon

bsrcon command {argument...}

DESCRIPTION

COMMANDS

/nodelayedack [ip|guid]


/delayedack_enable [ip|guid]


/m [letter] : mount


/get_log [ProviderName]


/minlog_lv dbg [Level : 0~7]


/write_log [ProviderName] "[LogData]"


/handler_use [0,1]


/bsrfsflt_status


/info


/status

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