Bug 1794460

Summary:	[RFE] boom: support for multi-volumes snapshots
Product:	Red Hat Enterprise Linux 8	Reporter:	jhouston
Component:	boom-boot	Assignee:	Bryn M. Reeves <bmr>
Status:	CLOSED MIGRATED	QA Contact:	cluster-qe <cluster-qe>
Severity:	low	Docs Contact:
Priority:	medium
Version:	8.1	CC:	agk, amkulkar, bdm, bmader, bmr, eddie.rowe, jbrassow, jentrena, jesper.schmidt, jwesterl, mcsontos, myllynen, ovasik, pdwyer, rhandlin, rtweed, sandkuma, sujagtap, swachira, vchepkov, vcojot, yferszt
Target Milestone:	rc	Keywords:	FutureFeature, MigratedToJIRA, Triaged
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:
Clones:	2177839 (view as bug list)		Environment:
Last Closed:	2023-09-23 15:59:03 UTC	Type:	Story
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:	2190228
Bug Blocks:	2177839

Description jhouston 2020-01-23 16:12:51 UTC

Description of problem:

Like most other enterprise customers, separate out system filesystems for /, /var, /tmp, /var/log, /var/crash, /var/log/audit, /home, etc. When we take a snapshot before patching or another risky activity, we take snapshots of all of these LVs. It would be great to be able to use boom to add a boot entry for snapshots is a situation like above. It is very easy to add a logical volume tag to a number of snapshot LVs (eg "--add tag rhel7.7_snapshot") like the entire list above. What I had in mind is extending the functionality of boom to be able to specify a logical volume tag as the "--rootlv" option instead of just being able to put a specific root snapshot lv. For example:
1. create all the required snapshot lvs for all system logical volumes using option "--addtag rhel7snap" for each.
2. create boom entry using the tag: boom create --title "RHEL7.7 snapshot - 20200121" --rootlv @rhel7snap

Then when the server is rebooted and you specify the "RHEL 7.7 snapshot - 20200121" entry to boot from, it not only boots from the root lv snapshot, but all the lv snapshots associated with all the system logical volumes.

Comment 3 Bryn M. Reeves 2020-01-23 19:47:55 UTC

Thanks for the interest in boom, and taking the time to file a bug. I've edited the title a little to make it more clear that this is asking about support for snapshots of more than just the root file system. Although there is an update to the boom package in the Red Hat Enterprise Linux 8.2 beta released this week that includes a number of new features and improvements booting is still limited to the root file system volume in this release: we do plan to support multi-volume snapshots in a future RHEL update but there is a system wide change needed before we can enable this functionality. This includes a mechanism to override the system fstab at boot time without modifying the snapshot contents. We have some prototypes that we are evaluating and we plan to start working on the snapshot manager features after the next boom release.

Boom is the first step in a plan to deliver improved bootable snapshot management and rollback capabilities: a white paper was published a couple of years ago that describes the full project - it's still fairly up to date with current work, and it might provide useful information in terms of the direction we are taking for these features. You can find it on GitHub here:

  https://github.com/snapshotmanager/snapshot-boot-docs

The boom project is hosted at:

  https://github.com/snapshotmanager/boom/

Feedback and suggestions on boom and the broader snapshot manager work are welcome, either via bugzilla or the upstream project pages. The snapshot manager and fstab substitution work will be delivered in different components, but I'll keep this open against boom for the time being so that we can keep track of it.

Comment 17 Bryn M. Reeves 2023-04-24 16:01:53 UTC

I have a prototype for multi-volume snapshots now that is working well in testing. It consists of a new systemd generator that runs in early boot and allows the content of /etc/fstab to be overridden on the kernel command line. This allows booting into a snapshot of the system state including auxiliary mounts such as /var, /home etc.

We are still reviewing the options for including this in the distribution and whether the functionality would be acceptable for systemd upstream but we hope to have more updates soon and will update the bugzilla as this work develops.

Comment 23 RHEL Program Management 2023-09-23 15:53:58 UTC

Issue migration from Bugzilla to Jira is in process at this time. This will be the last message in Jira copied from the Bugzilla bug.

Comment 24 RHEL Program Management 2023-09-23 15:59:03 UTC

This BZ has been automatically migrated to the issues.redhat.com Red Hat Issue Tracker. All future work related to this report will be managed there.

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