I've been running into an issue with zfs file systems hanging/freezing during our backup processes.
We currently perform backups to two servers, an onsite server and an offsite server. What we found is that when a single process is creating the snap, sending it and deleting an older snap it works fine. However, if we add the second process to do the same thing to the offsite server, we get a stuck process on the snapshot delete that cannot be killed. From what I can tell, the problem occurs when we attempt to delete any snapshot while a "zfs send" is in progress. Some things to note: * Only the volume with the stuck process freezes. Accessing files is fine, only ZFS commands are stuck. * We used different snapshot names, so the delete and send in both processes were not using the same snaps. * We also tried tiering where we would send snaps from the onsite backup server, but processes still froze. * We are using OmniOS. After some advising from Omni I used mdb to walk the threads. Here is the output: http://pastie.org/private/xism3bd6qixbfaugprqyqw They also mentioned it might be related to this bug: https://www.illumos.org/issues/2807 I attempted to do a crashdump, but after 30 minutes it was only 8% complete and we had to force the reboot. The box has 198GB of RAM, so I assume it was taking a while due to that. Does anyone know more about this issue? I am trying to figure out a way that I can run tiered backups to multiple locations without locking zfs. Thanks, Chris ------------------------------------------- illumos-discuss Archives: https://www.listbox.com/member/archive/182180/=now RSS Feed: https://www.listbox.com/member/archive/rss/182180/21175430-2e6923be Modify Your Subscription: https://www.listbox.com/member/?member_id=21175430&id_secret=21175430-6a77cda4 Powered by Listbox: http://www.listbox.com
