Re: mount prob: "log inconsistent or not a log"

["Jonathan C. Detert" <Jonathan.Detert@msoe.edu>]

* David Chinner <dgc@sgi.com> [071219 19:59]:
> On Wed, Dec 19, 2007 at 07:18:48PM -0600, Jonathan C. Detert wrote:
> > * Timothy Shimmin <tes@sgi.com> [071219 18:53]:
> > > Hi Jonathan,

-- snip --

> > > Jonathan.Detert@msoe.edu wrote:
> > > >This is what /var/log/messages has to say about the mount attempt:
> > > >-=-=-=-=-=-=-=--=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
> > > >Dec 19 17:42:30 quartz kernel: [ 9701.960000] XFS mounting filesystem sdb
> > > >Dec 19 17:42:30 quartz kernel: [ 9701.960000] XFS: Log inconsistent or not 
> > > >a log (last==0, first!=1)
> > 
> > --snip --
> > 
> > > >-=-=-=-=-=-=-=--=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
> > > >
> > > Every 512 bytes of the log is stamped with the cycle#.
> > > The cycle# is effectively the number of times the log has wrapped
> > 
> > -- snip --
> > 
> > > An "xfs_logprint -d /dev/sdb" will show what the cycle#s are
> > > and where the log records are. It might give an idea of the
> > > extent of the corruption.
> > 
> > Something occurred to me to point out:  the snapshot from yesterday has
> > the same problem.  How can that be?  Is is possible that the log has
> > been hosed for some time, and that the problem only reared its head now
> > because I had to remount?  I.e. is it possible for an xfs fs to be
> > mounted and used, even while the log is messed up?
> 
> No, it should not.
> 
> BTW, does "lost it's iSCSI connection" == "iSCSI server crashed"?

I'm not sure what you mean by 'iSCSI server'.  The linux 2.6.20
box (named 'quartz') is running the 'open-iscsi' 'iscsi initiator' software
(v2.0.730).  The ethernet cable connecting quartz to the iSCSI SAN switch
got accidentally removed while the SAN volume was mounted and in use as
/dev/sdb on quartz.  After the ethernet cable was reconnected, I was
unable to ls(1) the contents of the /dev/sdb's mountpoint.  So, I
rebooted quartz.  Incidentally, quartz had another SAN volume mounted as
/dev/sda, also with xfs on it, and it is able to mount /dev/sda just
fine.

> If so, is it possible that the iSCSI server is corrupted in some way?

if by that you mean the software that the iSCSI controller is running on
the iSCSI SAN hardware, then I suppose so.  I have a call into the
vendor on this already, and am waiting for a call-back.
-- 
Jon Detert
IT Systems Administrator, Milwaukee School of Engineering
1025 N. Broadway, Milwaukee, Wisconsin 53202, U.S.A.
--
"Music washes away from the soul the dust of everyday life."  Berthold Auerbach