pvebcache

pvebcache is PXVIRT's bcache management tool.

create

pvebcache create is used to convert a disk device into a bcache backend device.

pvebcache create /dev/sdb converts /dev/sdb into a bcache device.

list

The following command can be used to view bcache-related devices.

root@pvedevel:~# pvebcache list
name       type       backend-dev          cache-dev             state           size            cachemode      
bcache0    backend    sdc                  unknown              Running         80GB            writeback       
nvme0n1    cache      unknown              unknown              Running         32GB            unknown         
root@pvedevel:~#

stop

Stop a bcache backend device.

pvebcache stop bcache0

register

Re-register a bcache device.

pvebcache register /dev/sdb

cache create

Create a cache device.

pvebcache cache create /dev/nvme0n1p1

cache stop

Stop a cache device. If the cache device is in use, it cannot be stopped.

pvebcache cache stop /dev/nvme0n1p1

cache attach

Bind a cache device to a backend device.

pvebcache cache attach bcache0 --cache /dev/nvme0n1p1

cache detach

Detach a backend device from a cache device.

pvebcache cache detach bcache0

cache set

Set the cache policy for a backend device.

• cachemode # Cache mode
  • writethrough
  • writeback
  • writearound
  • none
• sequential # Sequential I/O size in KB
• wb-percent # Write-back percentage
• clear-stats # Clear statistics

pvebcache cache set bcache0 --cachemode writeback --sequential 4096 --wb-percent 20

The above command sets the bcache0 cache to writeback mode, with a sequential I/O size of 4MB and a write-back percentage of 20%.