Versions Compared

Version Old Version 28 New Version Current
Changes made by

헌규임

헌규임

Saved on

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.

...

Info

PrType (Persist Type) 1 : Type1 controls 'Write" of LUN. When use this option, shared disk resource can be used as lock disk. (Exclusive Write)
PrType (Persist Type) 3 : Typ3 controls "Access" of LUN. When use this option, exclusive LUN is needed for lock disk. 

  Small   Small disk capacity of about 1GB is available. But the content is not protected.



Configuration

SCSI-Lock resource can be configured in 2 ways with shared disk resource. Configuration process changes according to the attribute value of SCSI Lock resource.

...

  1. Install MCCS on both nodes
  2. Set group
  3. Add shared disk resource 
  4. Enable shared disk resource and check offline on both nodes
  5. Add SCSI Lock resource (Select new device path which is not assigned for shared disk resource.)
  6. Enable SCSI Lock resource and check Key in resource attribute in MCCS Console
  7. Change PrType 1 to 3 for attribute of SCSI Lock resource
  8. Configure dependency of resources (SCSI Lock resource must go online first)
  9. Test failover from node2 to 1
  10. Test failover from node1 to 2
  11. Customer applications that use the volume setting


Adding

There are two way to add a resource which one is select this from a group name and another is select this from a resource type.

...

Add the SCSI reservation application resource to a group.
Before configuring the SCSI reservation resource, you must configure the volume in advance by using the SCSI3 supporting storage.  

  1. When add a resource from a group name, select a group → right click → 'Add Resource'. 
    Image Removed
    [Figure] Adding Resource in a group

  2. Select 'SCSILOCK' from Resource Type lists and click 'Next' button. 
    Image Removed
    [Figure] Select Resource Wizard View
  3. Next steps are same as adding in resource type.

Adding in Resource Type

  1. ResourceType → Right Click → Click Add Resource
    Image Removed
    [Figure] Adding Resource in a resource type
     If all the information is retrieved, you can select a device path used as the SCSI reservation resource.
    Image Removed
    [Figure] Selecting driver letter View
    When there is no disk for SCSI Lock resource, "Disk Not Found" message appears.
    Image Removed

  2. [Figure] Disk Not Found
     If you select a device path used for the SCSI reservation resource, a name will be automatically recommended.

    [Figure] Select device pathSCSI Reservation Resource Added

  3. Click the 'Finish' and SCSI Lock resource is added.
    Image Removed
    [Figure] Adding SCSI Lock resource is completedbutton to add the SCSI reservation resource.
    You can immediately check the result in the management web console.

Deleting

Select resource type → right click → delete resource.

...

The deleted resource will immediately disappear from the management web console.

Status

The following table explains the status switching of the MCCS resource caused by a user's command and the status.
The command assumes that it is generated by a user.

...

StatusAgent commandDescriptionNote

Online

Disk key is exclusively reserved at an online node.
You cannot register a key at another node.

Offline

It ignores the reservation key stored. It first creates a new reservation key and switches to offline while maintaining the reservation.

 
Monitoring

Compares the key reserved in the disk and check if there is a reservation made on the disk.

 

Offline

1. Disk is reserved but the resource is still offline.
2. The actual offline state where the other node acquired a reservation.

Online

Register a key for a disk reservation and wait for a response from the other node.

 After going online once, the other node reservation is stolen. This is called preempt.

 
Monitoring

Compares the key reserved in the disk and check if there is a reservation made on the disk.

 

Trouble

It occurs when a reservation is stolen while going online.

Online

Register a key for a disk reservation and wait for a response from the other node.

After going online once, the other node reservation is stolen. This is called preempt.

 
OfflineIt ignores the reservation key stored. It first creates a new reservation key and switches to offline while maintaining the reservation. 

 

 

Attribute

Image Removed

[Figure] SCSI Lock Attribute view

SCSI Lock resource provides the following detailed attributes as well.
Setting are available in "Resource Unique Attribute" in resource's attribute tab.
Each attribute value has the following meanings:Display the unique attribute of SCSI reservation resource. 

Attribute

Description

Data Type

DefaultEditNote
DevicePath

Define the device path of disk to be used for reservation.

When register device path, DUID of connected disk will automatically obtain.

STRING X 
DiskDUID

DUID(Device Unique ID, 16 byte as Hex value) of disk is used as identifier. Specify DUID of reserve disk.

This value is secure when DriveLetter atribute us specified. Try not to insert this value yourself.

DUID information can be checked through scsicmd.cmd command and both nodes need to have the same value. 

STRING X 
Key

MAC address is used as Reserved-Key. This key is automatically set by agent. 

STRING X 
PreemptWaitCount

Time waiting for permission of other node before reservation

Waiting time is (PreemptWaitCount * MonitorInterval) seconds.

STRING2 timesO 
PrType

This attribute decides on how to give the permission of reserve disk access as Persist Type specified in SCSI3-PR spec.

There are 6 types bur MCCS uses 1 (Write Exclusive) or 3 (Exclusive Access).

1 (Write Exclusive) is used when same LUN is used with shared disk.

3 (Exclusive Access) is used when only Lock_Disk is used.

In this case, SCSI Lock agent LUN is required.

STRING

Prytpe = 1O 

...