Red Hat SummitChapter 5. Trim options on an LVM-VDO volume
The following are different available trim options for an LVM-VDO volume:
discard-
Performs online block discard operations to automatically discard unused blocks. For immediate discarding, use the
mount -o discardcommand. fstrim- Performs periodic discarding. The admin needs to schedule and monitor an additional process.
It is currently recommended to use fstrim application to discard unused blocks rather than the discard mount option because the performance impact of this option can be quite severe. For this reason, nodiscard is the default.
5.1. Enabling discard mount option on an LVM-VDO volume
You can enable the discard option on your LVM-VDO volume.
Prerequisites
- An LVM-VDO volume exists on your system.
Procedure
Enable the
discardoption on your volume:# mount -o discard /dev/vg-name/vdo-name mount-point
5.2. Setting up periodic TRIM operation
You can enable a scheduled TRIM operation on your system.
Prerequisites
- An LVM-VDO volume exists on your system.
Procedure
Enable and start the timer:
# systemctl enable --now fstrim.timer
Verification
Verify that the timer is enabled:
# systemctl list-timers fstrim.timer NEXT LEFT LAST PASSED UNIT ACTIVATES Mon 2021-05-10 00:00:00 EDT 5 days left n/a n/a fstrim.timer fstrim.service
You will not see any reference to a VDO volume, because the fstrim.timer runs across all mounted file systems.
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