LVM cache will be supported in RHEL6.7. The feature is already in position, but we need release notes stating this.
QA has verified the the following items required for "full support" in RHEL6.7.
1. The ability to create, remove, report on cache LVs created on top of linear, stripe or RAID LVs.
2. The cache LV components (data and metadata sub-LVs) can be linear, stripe or RAID LVs.
3. The user will be able to select the cache mode (either writeback or writethrough).
(This does not mean they will be able to switch cachemode while the cache is in-use)
4. The user will be able to select the granularity of cache chunks (i.e. chunk size).
5. Cache size, mode, and policy cannot be changed after creation.
Currently open 6.7 bugs from QA cache test cases:
1216214 - "attempt to access beyond end of device" when attempting a raid cache pool on 1k extent VG
1114113 - OOM issues when caching many volumes
1113770 - need a more graceful way to fail when attempting to cache RO devices
lvm2-2.02.118-2.el6 BUILT: Wed Apr 15 06:34:08 CDT 2015
lvm2-libs-2.02.118-2.el6 BUILT: Wed Apr 15 06:34:08 CDT 2015
lvm2-cluster-2.02.118-2.el6 BUILT: Wed Apr 15 06:34:08 CDT 2015
udev-147-2.62.el6 BUILT: Thu Apr 23 05:44:37 CDT 2015
device-mapper-1.02.95-2.el6 BUILT: Wed Apr 15 06:34:08 CDT 2015
device-mapper-libs-1.02.95-2.el6 BUILT: Wed Apr 15 06:34:08 CDT 2015
device-mapper-event-1.02.95-2.el6 BUILT: Wed Apr 15 06:34:08 CDT 2015
device-mapper-event-libs-1.02.95-2.el6 BUILT: Wed Apr 15 06:34:08 CDT 2015
device-mapper-persistent-data-0.3.2-1.el6 BUILT: Fri Apr 4 08:43:06 CDT 2014
cmirror-2.02.118-2.el6 BUILT: Wed Apr 15 06:34:08 CDT 2015
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory, and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.