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: 1. 2. 3. Actual results: Expected results: Additional info:
in main branch: https://sourceware.org/git/?p=lvm2.git;a=commit;h=390ff5be2fd9dda47f2bfd2db96de64acc925002
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)
Clarification: This feature is for cache and writecache origin (slow) volumes only. Pool and Pool meta volumes will not be tested with raid+integrity.
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
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