[dm-devel] RHEL6.6 dm-cache and dm-era

[Romu Hu]

Hi,

According to 
https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6-Beta/html-single/6.6_Release_Notes/index.html#bh-storage, 
dm-cache and dm-era have been added into RHEL6.6 as technology preview, 
but I couldn't find any other documentation about using dm-cache and 
dm-era.  I found the following utilities in

/usr/sbin/era_check
/usr/sbin/era_dump
/usr/sbin/era_invalidate

/usr/sbin/cache_check
/usr/sbin/cache_dump
/usr/sbin/cache_repair
/usr/sbin/cache_restore

I guess these utilities are related to dm-era and dm-cache, 
respectively.  There are only manpages for the cache utilities. After 
reading the manpages I still have no clue how to use these 
technologies.  I want to do a sanity check of these technologies on my 
SAN storage.  Is it possible to try dm-cache and dm-era without a SSD?  
e.g. using ram to imitate a fast block device..

Any idea?


Thanks
Romu