On Fri, 25 Jan 2019 13:52:55 +0000 Mike Keehan <[email protected]> wrote:
> On Thu, 24 Jan 2019 11:29:50 +0000 > unman <[email protected]> wrote: > > > On Thu, Jan 24, 2019 at 01:00:15AM -0500, Chris Laprise wrote: > > > On 01/23/2019 08:15 PM, [email protected] wrote: > > > > Mike Keehan: > > > > > Hi, > > > > > > > > > > I'm using Qubes Backup to save some of my qubes into another > > > > > VM. The backup VM has 18 Gb of storage available, but > > > > > whenever the backup file reaches 3Gb, the backup process just > > > > > hangs. > > > > > > > > > > No CPU usage, no error messages, just stops. The backup > > > > > window shows 40% complete, but never moves any further > > > > > (different % for different combinations of qubes in the > > > > > backup list). > > > > > > > > > > After waiting a considerable time (well, 5-10 minutes), > > > > > hitting Cancel in the backup window does cancel it. The rest > > > > > of the system is continuing to work without problem. Happens > > > > > every time I try to use Qubes backup. > > > > > > > > > > The Qubes Disk Space widget shows less than 50% disk used > > > > > overall, the backupVM shows only 18% disk used when the 3Gb > > > > > file has been saved. > > > > > > > > > > I'm stumped. > > > > > > > > > > Mike. > > > > > > > > Hi, > > > > > > > > You may have to wait longer than 5-10 minutes. I experience > > > > something similar when doing a full backup, except it's worse > > > > because i'm backing up like 2.5TB. It appears to hang for > > > > several hours at a time (and this happens more than once), but > > > > it does eventually make visible progress again. The whole > > > > process takes over 24 hours. This is why i do full backups very > > > > infrequently. > > > > > > > > For you it shouldn't take nearly as long because it's a lot less > > > > data, but the progress appearing to hang for a while seems to be > > > > normal. > > > > > > > > I'm using 3.2 tho, and i know they made changes to the backup > > > > mechanism under the hood in 4.0, so i'm not sure if this issue > > > > still applies in 4.0. > > > > > > Marek, > > > > > > Isn't this the null bytes bug in GNU tar? > > > > > > https://groups.google.com/d/msgid/qubes-users/f4d997d5-7191-06d0-e7bb-ef42745a7db5%40posteo.net > > > > > > It would be a good idea to update this in dom0. My own backup tool > > > uses GNU tar as well. > > > > > > -- > > > > > > Chris Laprise, [email protected] > > > https://github.com/tasket > > > https://twitter.com/ttaskett > > > PGP: BEE2 20C5 356E 764A 73EB 4AB3 1DC4 D106 F07F 1886 > > > > It seems a little early to judge. > > > > Mike - it looks from your comment as if you have been trying with > > subsets of the qubes? Can you confirm if these are running or > > stopped. > > > > Like jsnow, I'm regularly able to backup far more than 3G without > > issue, so it looks as if there's something particular about this > > scenario. It would be helpful if you could confirm the issue when > > all qubes you are backing up are stopped. > > Then try bisecting the qubes backup group - keep bisecting if you > > hit the problem again until you either find the problematic qubes > > or have backed them all up. > > > > OK, progress:) > > I can backup a list of stopped qubes, running out to a 10Gb file > without any issues. They all verify OK too. However, backing up > running qubes exhibits the problem. > > Starting up one of these qubes and trying to backup causes the > progress indicator to stop at some point, BUT, the data is still > being backed up to disk, and continues flowing for some time. When > the data flow stops, then I have to cancel the backup operation. > However, verifying the backup works OK - file size reported is > correct, and the verify process finishes successfully. I haven't > tried to actually restore one of these yet. > > I tried recording the process status of both dom0 and the backup vm > during the backups, but could not see any particular process dying > when the progress updater stopped moving. The tar processes stopped > in dom0 but I guess that was because they had finished creating the > private.img files. > > So it looks like backing up a live VM causes the backup process to > fail at some point, but not before the data is actually backed up. > > It doesn't look like a tar null issue as the data does get to disk OK. > It's just the control of the backup process getting out of step > somewhere. > > Mike. > I'm trying to debug the backup halting part way when backing up a running VM. (I have restored one of these backups successfully!) The backup.py script shows a debug log can be produced, but I can't find it - do I have to turn it on somehow? Mike. -- You received this message because you are subscribed to the Google Groups "qubes-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/qubes-users/20190128142814.3f0c4357.mike%40keehan.net. For more options, visit https://groups.google.com/d/optout.
