Use a typical cache block size
Use a typical cache block size

Devicemapper seems uncomfortable with such small blocks on such a large
cache. This should have the effect of postponing the point at which the
cache metadata sub-device runs out of room, for a long time but not
indefinitely. Once a cache device is setup, it is necessary to stick with
the cache block size. Stopping the cache and making a whole new one with
a different cache block size is something we may find that it is advisable
to do, but is a future project.

Excerpt from devicemapper logs:
[Mar29 10:06] device-mapper: cache: You have created a cache device with a lot of individual cache blocks (128183735)
All these mappings can consume a lot of kernel memory, and take some time to read/write.
Please consider increasing the cache block size to reduce the overall cache block count.

Signed-off-by: mulhern <7b51bcf507bcd7afb72bf8663752c0ddbeb517f6@redhat.com>

stratis-storage/stratisd,trgill/stratisd,mulkieran/stratisd,stratis-storage/stratisd,trgill/stratisd,mulkieran/stratisd,stratis-storage/stratisd