Bug 2159820

Summary:	allow cache or writecache over raid+integrity LV
Product:	Red Hat Enterprise Linux 9	Reporter:	David Teigland <teigland>
Component:	lvm2	Assignee:	David Teigland <teigland>
lvm2 sub component:	Cache Logical Volumes	QA Contact:	cluster-qe <cluster-qe>
Status:	VERIFIED ---	Docs Contact:
Severity:	unspecified
Priority:	unspecified	CC:	agk, cmarthal, heinzm, jbrassow, mcsontos, msnitzer, prajnoha, zkabelac
Version:	9.1	Keywords:	Triaged
Target Milestone:	rc
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:	lvm2-2.03.21-1.el9	Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:		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 David Teigland 2023-01-10 21:02:45 UTC

Description of problem:

lvm does not currently permit adding a cache or writecache over a raid+integrity LV.  This limitation was originally meant to introduce the integrity feature incrementally, but it's now been in use for some time and we have see interest in using writecache with raid+integrity.

That patch will simply remove the RULE lines in the command line definitions that disallow the commands.

Steps are:
1. create a raid+integrity LV.
2. add a cache or writecache to the LV.

I may limit the commands that can be used to add cache|writecache to the basic variant: lvconvert --type cache|writecache LV.

As to the question of whether the user should be allowed to add/remove integrity from a raid LV while there is a cache|writecache attached, I'm inclined to restrict that somewhat, perhaps only allowing the removal of integrity from raid while cache|writecache is attached.

Version-Release number of selected component (if applicable):


How reproducible:


Steps to Reproduce:
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Actual results:


Expected results:


Additional info:

Comment 1 David Teigland 2023-04-06 16:40:52 UTC

in main branch:
https://sourceware.org/git/?p=lvm2.git;a=commit;h=390ff5be2fd9dda47f2bfd2db96de64acc925002

Comment 2 David Teigland 2023-04-06 17:11:15 UTC

Regarding unique limitations of the caching/raid/integrity combination:

- can remove integrity from raid+integrity while caching
- cannot add integrity to raid while caching
- can remove image from raid+integrity while caching
- cannot add image to raid+integrity while caching
- cannot snapshot raid+integrity while caching (this may be enabled in 2179430)

Comment 4 Corey Marthaler 2023-04-25 16:43:08 UTC

Clarification: This feature is for cache and writecache origin (slow) volumes only. Pool and Pool meta volumes will not be tested with raid+integrity.

Comment 6 Corey Marthaler 2023-05-17 18:43:24 UTC

Initial cache and writecache testing over raid+integrity is complete, with the following caveat, no snapshot filesystem testing has been done yet.

Marking Verified:Tested with the latest rpms.

kernel-5.14.0-306.el9    BUILT: Sat Apr 29 05:45:15 PM CEST 2023
lvm2-2.03.21-1.el9    BUILT: Fri Apr 21 02:33:33 PM CEST 2023
lvm2-libs-2.03.21-1.el9    BUILT: Fri Apr 21 02:33:33 PM CEST 2023

Comment 9 Corey Marthaler 2023-05-31 18:57:36 UTC

Marking VERIFIED now that cache and write cache test scenarios have passed the second build as well. Again, with the caveat that no snapshot filesystem testing has been done yet.

kernel-5.14.0-305.el9    BUILT: Thu Apr 27 03:00:24 PM CEST 2023
lvm2-2.03.21-2.el9    BUILT: Thu May 25 12:03:04 AM CEST 2023
lvm2-libs-2.03.21-2.el9    BUILT: Thu May 25 12:03:04 AM CEST 2023