I have found that there is an issue with unmounting ZFS snapshots: the /sbin/umount "hangs" after unmounting.
The test system is i386, but I can reproduce this issue on amd64 too. # uname -a FreeBSD alpha.vosz.local 8.1-STABLE FreeBSD 8.1-STABLE #0: Tue Oct 19 18:47:05 MSD 2010 r...@alpha.vosz.local:/usr/obj/usr/src/sys/GENERIC i386 How to try to repeat: # zfs snapshot pool/v...@test # zfs list -t all -r pool/var NAME USED AVAIL REFER MOUNTPOINT pool/var 4,86M 2,99G 4,86M /var pool/v...@test 0 - 4,86M - # mount -t zfs pool/v...@test /mnt # mount ... pool/v...@test on /mnt (zfs, local, noatime, read-only) # umount /mnt At this point umount hangs and it's impossible to kill it even with the `kill -9`. >From the working console I can see that: 1. snapshot is unmounted successfully # mount pool/root on / (zfs, local) devfs on /dev (devfs, local, multilabel) pool/home on /home (zfs, local) pool/tmp on /tmp (zfs, local) pool/usr on /usr (zfs, local) pool/usr/src on /usr/src (zfs, local) pool/var on /var (zfs, local) 2. the umount is waiting for disk #ps | egrep 'PID|umount' PID TT STAT TIME COMMAND 958 0 D+ 0:00,04 umount /mnt # procstat -t 958 PID TID COMM TDNAME CPU PRI STATE WCHAN 958 100731 umount - 3 133 sleep mntref Can anybody confirm this issue? Any suggestions? -- Alexander Zagrebin _______________________________________________ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
