5.4. Increasing block map cache size to enhance performance

Procedure

1. Check the current cache size of your LVM-VDO volume:

   # lvs -o vdo_block_map_cache_size

     VDOBlockMapCacheSize
                  128.00m
                  128.00m

2. Deactivate the LVM-VDO volume:

   # lvchange -an <vg_name>/<vdo_volume>

3. Change the LVM-VDO setting:

   # lvchange --vdosettings "block_map_cache_size_mb=640" <vg_name>/<vdo_volume>

   Replace 640 with your new cache size in megabytes.

   注意

   The cache size must be a multiple of 4096, within the range of 128 MB to 16 TB, and at least 16 MB per logical thread. Changes take effect the next time the LVM-VDO device is started. Already running devices are not affected.

4. Activate the LVM-VDO volume:

   # lvchange -ay <vg_name>/<vdo_volume>