In the last recipe, we created a pool, cache-pool
, based on SSDs. We will now use this pool as a cache tier for the erasure-coded pool, EC-pool
, that we created earlier in this chapter:
The following instructions will guide you through the creation of a cache tier with the writeback
mode and setting the overlay with an EC-pool
:
ceph osd tier add <storage_pool> <cache_pool>
:# ceph osd tier add EC-pool cache-pool
writeback
or read-only
. In this demonstration, we will use writeback
, and the syntax is: ceph osd tier cachemode <cache_pool> writeback
:# ceph osd tier cache-mode cache-pool writeback
ceph osd tier set-overlay <storage_pool> <cache_pool>
:# ceph osd tier set-overlay EC-pool cache-pool
EC-pool
has tier
, read_tier
, and write_tier
set as 48
, which is the pool ID for the cache-pool
. Similarly, for cache-pool
, the settings will be: tier_of
set to 47
and cache_mode
as writeback
. All these settings imply that the cache pool is configured correctly:# ceph osd dump | egrep -i "EC-pool|cache-pool"
3.133.154.64