/ 2005-09-17 14:27:10 +0800 \ Bear Wolf: > I also found the process dead, that is "pdflush" > there're 2 "pdflush" always running on my system, > but one is dead after I create the 3rd snapshot volumes and access the > source volume then sync it is not "dead", it is in "uninteruptible sleep". that is a big difference. yes, those are the kernel threads responsible for the sync. there are initially two of them per cpu. if they (try to) sync to some device mapper target which is suspended, they themselves get suspended. this can hang the system: no io possible, nothing possible anymore that needs io... > -bash-3.00# ps x > PID TTY STAT TIME COMMAND > 1 ? S 0:01 init [2] > 2 ? S 0:00 [migration/0] > 3 ? SN 0:00 [ksoftirqd/0] > 4 ? S< 0:00 [events/0] > 5 ? S< 0:00 [khelper] > 6 ? S< 0:00 [kthread] > 8 ? S< 0:00 [kacpid] > 70 ? S< 0:00 [kblockd/0] > 73 ? S< 0:00 [khubd] > 129 ? S 0:00 [pdflush] > 130 ? D 0:00 [pdflush] > 132 ? S< 0:00 [aio/0] > 131 ? S 0:00 [kswapd0] > 134 ? S< 0:00 [xfslogd/0] > 133 ? S 0:00 [cifsoplockd] > 135 ? S< 0:00 [xfsdatad/0] > 136 ? S 0:00 [xfsbufd] > 723 ? S< 0:00 [kseriod] > 773 ? S 0:00 [scsi_eh_0] > 777 ? S< 0:00 [ata/0] > 801 ? S< 0:00 [kcryptd/0] > 934 ? S< 0:00 [kcopyd] > 1330 ? Ss 0:00 syslogd -m 0 > 1334 ? Ss 0:00 klogd -x > 1343 ? Ss 0:00 /usr/httpd/bin/httpd > 1353 ? Ss 0:00 crond > 1359 ? Ss 0:00 /bin/profamd > 1479 tty1 Ss 0:00 -bash > 1481 tty2 Ss+ 0:00 -bash > 1483 tty3 Ss+ 0:00 /sbin/mingetty tty3 > 1485 tty4 Ss+ 0:00 /sbin/mingetty tty4 > 1487 tty5 Ss+ 0:00 /sbin/mingetty tty5 > 1903 ? S 0:00 [xfssyncd] > 1915 tty1 D+ 0:00 sync > 2037 pts/0 R+ 0:00 ps x -- : Lars Ellenberg Tel +43-1-8178292-0 : : LINBIT Information Technologies GmbH Fax +43-1-8178292-82 : : Schoenbrunner Str. 244, A-1120 Vienna/Europe http://www.linbit.com : _______________________________________________ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
