Am Mon, 9 May 2016 13:13:53 -0400 schrieb Nicholas D Steeves <nstee...@gmail.com>:
> On May 7, 2016 7:43 AM, "Kai Krakow" <hurikha...@gmail.com> wrote: > > > > Am Thu, 5 May 2016 08:35:37 +0200 > > schrieb Kai Krakow <hurikha...@gmail.com>: > > > > > Am Tue, 3 May 2016 08:48:14 +0200 > > > schrieb Kai Krakow <hurikha...@gmail.com>: > > > > [...] > [...] > > > [...] > [...] > [...] > > > > > > With the snapshot and sync related bits disabled in my script, I > > > no longer experience freezing df/du/... commands. > > > > Ah well, I still do - it just triggers much less often. > > > > But I can track it down to the automounter now: As soon as I stop > > the automounter of my backup device, du/df/etc no longer hang. > > Still I'm not sure if the problem is originating from btrfs or > > autofs itself. > > Hi Kai, > > If it's anything like what I've encountered it can be worked around > with careful use of sleep, sync, btrfs sub sync and/or btrfs fi sync. > Also, if it's a similar issue to my own then from what I've read on > this list it's a timing or race issue (or maybe a locking issue). > There's a Debian bug where someone is testing out different > values/strategies. The values/strategy I use can be found in > btrfs-borg on github. If I'm correct, you'll probably also need to > script in delays to things time to settle with your automounter. > > Of course, ideally someone will one day spend the time debugging > what's actually going on. Thanks for the pointer... Maybe I could just remove the idle timeout of the automount unit, so it never tries to automatically unmount once mounted. Tho, I prefer if it did that. I don't want the backup FS being online all of the time. Maybe such a race results from btrfs still doing background work (like removing snapshots) while there is no longer a user of the mount point running (processes terminated) - and now, when systemd's automounter tries to unmount, it doesn't work and autofs hangs. If I know experience hanging processes, I can simply "systemctl restart mnt-usbdevice.automount" and the hanging processes start to work again. -- Regards, Kai Replies to list-only preferred. -- 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
