Bug 2007803

Summary: VDO may behave badly when its backing store is changed during suspend
Product: Red Hat Enterprise Linux 9 Reporter: Matthew Sakai <msakai>
Component: kmod-kvdoAssignee: Matthew Sakai <msakai>
Status: CLOSED ERRATA QA Contact: Filip Suba <fsuba>
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: 9.0CC: awalsh, cwei, fsuba, pvlasin
Target Milestone: rcKeywords: Triaged
Target Release: ---Flags: pm-rhel: mirror+
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: kmod-kvdo-8.1.1.371-15.el9_0 Doc Type: If docs needed, set a value
Doc Text:
Story Points: ---
Clone Of:
: 2060791 (view as bug list) Environment:
Last Closed: 2022-05-17 15:49:27 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:
Bug Depends On:    
Bug Blocks: 2060791    

Description Matthew Sakai 2021-09-24 23:55:48 UTC 
Description of problem:
If a VDO device is suspended, and a new table is loaded that points to a new backing device, after resuming the VDO will continue to write some metadata to the original device. (This especially affects metadata related to the deduplication index.) It also retains a reference to the original device, possibly preventing the original device from being removed.

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


How reproducible:


Steps to Reproduce:
1. Create a VDO, add some data, and suspend it.
2. Change the underlying device stack, for example by adding a cache or replacing the backing store with a RAID.
3. Load a new table for the VDO reflecting the new backing device, and resume the VDO.


Actual results:
The exact effect likely varies but at a minimum it may result in a loss of deduplication information.


Expected results:
Normal VDO operation

Additional info:
This issue can be worked around by stopping the VDO device completely and restarting it with the new table.
Comment 9 Filip Suba 2022-03-16 09:03:40 UTC 
Verified with kmod-kvdo-8.1.1.371-15.el9_0.
Comment 11 errata-xmlrpc 2022-05-17 15:49:27 UTC 
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 (new packages: kmod-kvdo), and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2022:3919