18.09.2017 05:31, Dave пишет: > Sometimes when using btrfs send-receive, I get errors like this: > > ERROR: parent determination failed for <subvolume name> > > When this happens, btrfs send-receive backups fail. And all subsequent > backups fail too. > > The issue seems to stem from the fact that an automated cleanup > process removes certain earlier subvolumes. (I'm using Snapper.) > > I'd like to understand exactly what is happening so that my backups do > not unexpectedly fail. >
You try to send incremental changes but you deleted subvolume to compute changes against. It is hard to tell more without seeing subvolume list with uuid/parent uuid. > In my scenario, no parent subvolumes have been deleted from the > target. Some subvolumes have been deleted from the source, but why > does that matter? I am able to take a valid snapshot at this time and > every snapshot ever taken continues to reside at the target backup > destination (seemingly meaning that a parent subvolume can be found at > the target). > > This issue seems to make btrfs send-receive a very fragile backup > solution. btrfs send/receive is not backup solution - it is low level tool that does exactly what it is told to do. You may create backup solution that is using btrfs send/receive to transfer data stream, but then do not blame tool for incorrect usage. To give better advice how to fix your situation you need to describe your backup solution - how exactly you select/create snapshots. I hope, instead, there is some knowledge I'm missing, that > when learned, will make this a robust backup solution. > > Thanks > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
