Date: Wed, 15 Oct 2008 19:24:28 +1100 From: Peter Jeremy <peterjeremy@optushome.com.au> To: freebsd-stable@freebsd.org Subject: System hanging during dump Message-ID: <20081015082428.GE26536@server.vk2pj.dyndns.org>
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--ZJcv+A0YCCLh2VIg Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Last night, I attempted a full, compressed backup of my 181GB /home (on a PATA disk) to a remote system. The backup started at 2159 and everything appeared normal until about 0040 when the system became non-responsive and this lasted until the dump completed at 1033. This is the first full backup of /home I've made for several years (due to lack of space). I noticed the non-responsiveness at about 0500 when: - The dump, gzip and fifo pipeline were running normally. - A 'systat -v' I had started was running normally (though it reported an excessive number of 'D' processes). Other values all appeared normal. - No response to return key at a zsh prompt - No response to up/down arrows in mutt [above all done in pre-existing ssh sessions from another host] - telnet to port 22 connected but didn't produce a banner. The duration above is based on system logs - which show nothing happened during this period. At the end, there were various anomolous entries: Oct 15 10:33:27 server ntpd[750]: too many recvbufs allocated (40) Oct 15 10:33:30 server sshd[947]: error: accept: Software caused connection= abort Oct 15 10:33:34 server kernel: TCP: [192.168.123.123]:59516 to [192.168.123= =2E200]:25 tcpflags 0x4<RST>; syncache_chkrst: Spurious RST without matchin= g syncache entry (possibly syncookie only), segment ignored Possibly useful information: The dump pipeline was: dump -uaL0 -C 32 -f - /home | reblock | gzip [stdout connected to socket to remote server] 'reblock' is basically a 200MB FIFO I wrote to desynchronise the (often I/O bound) dump from the CPU-bound gzip. server% uname -a FreeBSD server.vk2pj.dyndns.org 7.0-STABLE FreeBSD 7.0-STABLE #18: Sun May = 18 15:02:39 EST 2008 root@server.vk2pj.dyndns.org:/var/obj/k7/usr/src/s= ys/server i386 server% df -ki Filesystem 1024-blocks Used Avail Capacity iused ifree %iused M= ounted on /dev/ad0s3d 204648864 181911710 6365246 97% 1703016 11353942 13% /= home About the only think that happened at around this time was nightly updates. These start at 0005, fetching CTM cvs-cur updates, applying them to /home/ncvs, then cvs updating /home/ports. Looking at timestamps, /home/ports/graphics/icod/CVS/Entries was updated at 0042 and /home/ports/graphics/imlib2_loaders/CVS/Entries (the next entry) was updated at 1034. Whilst /home is fairly full, I can't see that the snapshot meta and rollback data would have occupied the 20GB free (and no 'out-of-space' messages were generated). Is there some limit on the number of inodes that can be updated whilst a snapshot exists? Has anyone else seen anything similar? --=20 Peter Jeremy Please excuse any delays as the result of my ISP's inability to implement an MTA that is either RFC2821-compliant or matches their claimed behaviour. --ZJcv+A0YCCLh2VIg Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (FreeBSD) iEYEARECAAYFAkj1qLwACgkQ/opHv/APuIeREACgpjCPVxERhgEs0D8grqn3uGc3 +28AniXCh990RNkp/msGrhs3CffIMBtV =XdEX -----END PGP SIGNATURE----- --ZJcv+A0YCCLh2VIg--
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