don't throw away failed snapshot

[lnussel]

On one of my systems I repeatedly have a problem where zypper dup fails with exit code 107 when run from transactional-update dup. The snapshot is thrown away then. Running it from within transactional-update shell works though. So hard to debug, esp since zypper has to download all packages again. Would it be possible to add a config option or command line switch to not throw away the snapshot even if whatever happened failed? That way it would be possible to inspect the inside after the failure.

[lnussel]

ha, found the reason. The error messages and the mkinitrd output at the end were misleading

update-alternatives: error: unable to create file '/var/lib/alternatives/gs.rpm-tmp': Read-only file system
warning: %post(ghostscript-9.52-2.2.x86_64) scriptlet failed, exit status 2

anyways, the request to keep also failed snapshots stays

[thkukuk]

And who cleans up the failed snapshots?
For debugging, there is "transactional-update shell dup"
One of our marketing promises is, that failed updates are deleted immediately so that they cannot harm in any way, not even by eating up disk space. One of the biggest concerns in all talks with customers.

[laenion]

Agreeing to what Thorsten said: the shell option is supposed to be used for debugging.

However from a user's perspective it may indeed be an idea to introduce a --keep option. However we'd still have to think about how to clean up such a snapshot. One idea may to to fill snapper's userdata field with a dedicated value, e.g. transactional-update-failed=yes (similarly to the current transactional-update-in-progress=yes to detect power failures) and set a cleanup algorithm for such snapshots on next run.

[lnussel]

a failed snapshot would get cleaned up just like any other, right? So while the mechanism could be optimized for more aggressive cleanup of course it's just that, an optimization. Ie not strictly required. Since the keep option wouldn't be default the risk of having failed snapshots consume disk space would be a consciously taken one. In the situation I had I would have preferred investing disk space over time spent on manual zypper dup.