9.1-STABLE, live lock up, seems that it is ZFS lockup in "zfskern{txg_thread_enter}" state "tx->tx"

[Lev Serebryakov]

Hello, freebsd-fs.

  I have 9.1-STABLE (r244958) system, amd64, 8GiB memory.

  Two SATA disks, 750Gb each.

  Disks are partitoned into 7 (BSD) partitons (exactly the same), 5 of
 these pairs are joined into gmirrors for "system" FSes (UFS2), one
 pair is used for swaps and 7th pair is used as zmirror for /usr/home.

   Tonight system becomes unusable, as every process which try to read
 directories in /usr/home (like "ls ~" or "find /usr/home -type f")
 hangs forever. I could login to system, login shell starts, but if I
 run "ls" right after -- it hangs. Every periodic process, which try
 to read home FS (directories, not files!) hangs. It looks, like
 stat() calls on this FS hangs, but not open()/read()/write()/close().

  One thing I fins suspicious in different system diagnostics, is
  kernel thread "zfskern{txg_thread_enter}" which is shown in state
  "tx->tx" forever.

  Disks looks completely OK according to smartd/smartctl, no hardware
 errors in dmesg, etc.

===============================================
# zpool status
  pool: pool
 state: ONLINE
status: The pool is formatted using a legacy on-disk format.  The pool can
        still be used, but some features are unavailable.
action: Upgrade the pool using 'zpool upgrade'.  Once this is done, the
        pool will no longer be accessible on software that does not support feature
        flags.
  scan: resilvered 32.1G in 0h34m with 0 errors on Sat Jun  2 16:22:59 2012
config:

        NAME         STATE     READ WRITE CKSUM
        pool         ONLINE       0     0     0
          mirror-0   ONLINE       0     0     0
            ada0s1h  ONLINE       0     0     0
            ada1s1h  ONLINE       0     0     0

errors: No known data errors
================================================


-- 
// Black Lion AKA Lev Serebryakov <lev at FreeBSD.org>