hi All,
thanks for the responses.
After being dropped into the
# Filesystem repair
prompt,
( on account of “inode 27344909 has illegal blocks” )
following warm reboot (via “reboot”) after finding (SAN ) filesystem in read-only
mode yesterday morning (possibly because of HBA fault on SAN) , I ran
fsck –r /data
(Linux version 2.6.18-92.1.18.el5 , Red Hat 4.1.2-42 , ext3 filesystem)
This took a couple of hours or so , prompting me for various changes
all of which I accepted. This appeared to complete OK, but then the
system would not boot, with the following error from the qla2xxx driver.
.
.
qla2xxx 0000:05:0d.0: Mailbox command timeout occurred. Scheduling ISP abort.
qla2xxx 0000:05:0d.0: Mailbox command timeout occurred. Scheduling ISP abort.
.
etc
However after powering down the system and cold-booting, the system was able
to boot up and mount the repaired filesystem without any obvious damage, but with
abnormal not to mention scary looking boot messages and ongoing warnings from
multipath.
This morning (as I sort of expected) the filesystem had dropped back down to read-only mode, but meanwhile
the source of our woes was identified, a fibre port on the SAN controller which was degraded but not
completely failed, so that there had been no clean failover to the twin controller, and therefore a degraded
virtual device was presented to the O/S, with consequence for the filesystem.
After that port and controller was quarantined, this time around I did a cold power-off reboot
of the server , and this time there was a more normal looking boot and the filesystem
came up normally without any repair being requested.
(My hypothesis is that in this situation – i.e. ext3 filesystem has put itself in read-only mode –
a warm boot , via reboot, does not cleanly remount the filesystem and apply the journal
quite like a cold power-off reboot does. I think it is likely that the lengthy
session of me answering “yes” to fsck’s interactive repair, the first time around, simply applied all of the
fixes that would automatically have been done from the journal , had I cold-rebooted in the first place.
However that is only a hunch. But I will be making sure to do cold power-off reboots in general, in
future.)
Another lesson is that a sophisticated system of twin SAN controllers with failover does not protect
against a situation where a device is degrading rather than failing completely.
Thanks again for the responses and sorry if my questions were a bit basic but I have
been dropped in a little out of my depth with this system.
Cheers
AMcC
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