Hi,
dm-cache is a hot-spot cache. Ie. you need multiple accesses to the same
block to get it promoted into the cache (depending on the policy plugin
btw).
If your patterns is one-time-only access type, it ain't warm the cache.
Heinz
On 07/26/2013 05:24 PM, Dave Pitts wrote:
Hello:
I've been trying to do some performance testing for a client and can't
seem to get the dm-cache warmed. The values displayed in the "dmsetup
status" command seem too low. I've been trying to use the "raw"
devices setup for the cache and NOT use a file system or database.
I've tried sequential writes/reads to the devices (ie. dd ) and
dividing up the space to be tested and do I/O over a number of
segments to try to break any sequential I/O tests. Any ideas as to
what I may doing wrong? Do I need to randomize the I/O?
System: RHEL 7.0 Alpha3, 3.9.7 kernel
Thanks in advance..
--
dm-devel mailing list
dm-devel@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/dm-devel
