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| Info |
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The files used in the configuration file of the SB handler must be described as absolute paths. |
Compatibility
Describes compatibility issues that arise from working with third-party products. Most compatibility issues in BSR appear as errors because the functionality or behavior of another program or module affects the operation of BSR.
Volume references
BSR maintains dereferencing of volumes internally during resource operations. Volume reference count is used to manage the lifecycle of BSR volumes by incrementing when a reference is acquired and decrementing when a reference is de-referenced.
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Device reference errors
BSR internally maintains reference count for backing devices. The reference count is incremented when a device is opened by a particular process and decremented when it is closed to manage the lifecycle for the device and to force a particular process to no longer reference the device volume.
Problems arise when the reference count is non-zero, either at the beginning of configuring the BSR resource or during the process of umounting the device. Because some process opened the device and never closed it, BSR detects this and treats it as an error.
Resource configuration errors
If any process is referencing the BSR resource BACKING DEVICE, attaching the device will fail with the following error. 16 The error code corresponds to EBUSY.
| Info |
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[open_backing_dev] [DRIVER:140] bsr_erro<3> bsr bsr0/0 bsr0: Failed to open("/dev/sdb1") backing device with -16 |
DOWN Errors
If the number of references to the device is not zero at the time of resource down, down will fail and the following log will be output.
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bsr volume(r0) Secondary failed (error=0: State change failed: (-12) Device is held open by someone |
To resolve this issue, you must need to identify the process or module that is referencing the BSR volume and take steps to reduce the number of references to the volume, such as disabling forcing the behavior of that modulemodule to stop (fuser -ck).
For example, on Ubuntu 20.04 and later, multipath-tools (0.8.3) must be prevented from making references to the bsr volume through have the following exception handling in multipath.conf . Otherwise, to prevent references to the bsr device from occurring, otherwise multipath-tools will continue to reference the bsr volume, making it impossible to bring down.
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blacklist {
devnode "^(sd)[a-z]"
devnode "^(bsr)[0-9]"
}
|