Bug 1284661

Summary:	"is already cached" message would be easier to read if attempting to cache a cache
Product:	Red Hat Enterprise Linux 7	Reporter:	Corey Marthaler <cmarthal>
Component:	lvm2	Assignee:	Zdenek Kabelac <zkabelac>
lvm2 sub component:	Cache Logical Volumes	QA Contact:	cluster-qe <cluster-qe>
Status:	CLOSED WONTFIX	Docs Contact:
Severity:	low
Priority:	unspecified	CC:	agk, heinzm, jbrassow, msnitzer, prajnoha, zkabelac
Version:	7.2
Target Milestone:	rc
Target Release:	---
Hardware:	x86_64
OS:	Linux
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Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2020-12-15 07:38:43 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Corey Marthaler 2015-11-23 19:44:26 UTC

Description of problem:

# Already mirrored
[root@host-122 ~]# lvconvert -m 1 vg/mirror
  vg/mirror already has image count of 2.

# Already a thin pool 
[root@host-122 ~]# lvconvert --type thin-pool vg/tpool
  LV vg/tpool is already pool.

# Wouldn't just a "is already cached" message be easier to read here?
[root@host-122 ~]# lvcreate --type cache-pool -n cpool -L 100M vg
  Logical volume "cpool" created.
[root@host-122 ~]# lvcreate --type cache -L 100M -n corigin --cachepool vg/cpool
  Logical volume "corigin" created.

[root@host-122 ~]# lvconvert --type cache corigin --cachepool vg/cpool
  Cache is not supported with cache segment type of the original logical volume vg/corigin.
[root@host-122 ~]# lvconvert --type cache vg/corigin --cachepool vg/cpool
  Cache is not supported with cache segment type of the original logical volume vg/corigin.


Version-Release number of selected component (if applicable):
3.10.0-327.el7.x86_64
lvm2-2.02.130-5.el7    BUILT: Wed Oct 14 08:27:29 CDT 2015
lvm2-libs-2.02.130-5.el7    BUILT: Wed Oct 14 08:27:29 CDT 2015
lvm2-cluster-2.02.130-5.el7    BUILT: Wed Oct 14 08:27:29 CDT 2015
device-mapper-1.02.107-5.el7    BUILT: Wed Oct 14 08:27:29 CDT 2015
device-mapper-libs-1.02.107-5.el7    BUILT: Wed Oct 14 08:27:29 CDT 2015
device-mapper-event-1.02.107-5.el7    BUILT: Wed Oct 14 08:27:29 CDT 2015
device-mapper-event-libs-1.02.107-5.el7    BUILT: Wed Oct 14 08:27:29 CDT 2015
device-mapper-persistent-data-0.5.5-1.el7    BUILT: Thu Aug 13 09:58:10 CDT 2015
cmirror-2.02.130-5.el7    BUILT: Wed Oct 14 08:27:29 CDT 2015
sanlock-3.2.4-1.el7    BUILT: Fri Jun 19 12:48:49 CDT 2015
sanlock-lib-3.2.4-1.el7    BUILT: Fri Jun 19 12:48:49 CDT 2015
lvm2-lockd-2.02.130-5.el7    BUILT: Wed Oct 14 08:27:29 CDT 2015

Comment 3 Jonathan Earl Brassow 2020-09-01 15:20:54 UTC

agreed, that would make things behave the same as other scenarios.  There may be a future where we allow multiple levels of caching, but for now this is a good idea.  Will defer to RHEL8 though.

Comment 5 RHEL Program Management 2020-12-15 07:38:43 UTC

After evaluating this issue, there are no plans to address it further or fix it in an upcoming release.  Therefore, it is being closed.  If plans change such that this issue will be fixed in an upcoming release, then the bug can be reopened.