Chapitre 9. Enabling caching to improve logical volume performance
You can add caching to an LVM logical volume to improve performance. LVM then caches I/O operations to the logical volume using a fast device, such as an SSD.
The following procedures create a special LV from the fast device, and attach this special LV to the original LV to improve the performance.
9.1. Caching methods in LVM
LVM provides the following kinds of caching. Each one is suitable for different kinds of I/O patterns on the logical volume.
dm-cacheThis method speeds up access to frequently used data by caching it on the faster volume. The method caches both read and write operations.
The
dm-cachemethod creates logical volumes of the typecache.dm-writecacheThis method caches only write operations. The faster volume stores the write operations and then migrates them to the slower disk in the background. The faster volume is usually an SSD or a persistent memory (PMEM) disk.
The
dm-writecachemethod creates logical volumes of the typewritecache.
Ressources supplémentaires
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lvmcache(7)man page
