LVM¶
Read/Write Cache¶
Enable Cache¶
Create ${CACHE_LV}:
lvcreate --type raid1 -m 1 -n ${CACHE_LV} ${VG} ${CACHE_PV1} ${CACHE_PV2}
Enable cache:
lvconvert --type cache --cachepool ${CACHE_LV} --cachemode writeback --chunksize 256 ${VG}/${LV}
Tip
Only use ~75% of an SSD to ensure good performance.
Run TRIM on the empty space (blkdiscard(8)).
Disable Cache¶
lvconvert --splitcache ${VG}/${LV}
Run Raid Check¶
lvchange --syncaction check ${VG}/${LV}
Tip
You can use --maxrecoveryrate ${RATE} to reduce the impact on performance.
Rate is per device. Default unit is KiB/s/device.