fsck is failing to clean a filesystem
smithi at nimnet.asn.au
Wed Feb 10 10:57:09 UTC 2016
On Wed, 10 Feb 2016 10:22:36 +0100, Polytropon wrote:
> On Wed, 10 Feb 2016 20:11:03 +1100 (EST), Ian Smith wrote:
> > On Tue, 9 Feb 2016 22:10:14 -0800, Paul Beard wrote:
> > > > On Feb 9, 2016, at 9:14 PM, Ian Smith <smithi at nimnet.asn.au> wrote:
> > > >
> > > > I know your problem is with /usr, but I
> > > > find the fact that /var is full or too nearly so rather concerning, and
> > > > wonder whether that might have contributed to your problem in some way,
> > > > and whether freeing up some space there might yet help?
> > >
> > > Yeah, itÿÿs a mess, running a full system in a 64Gb virtual disk is
> > > probably asking for trouble. I think there is some cruft in /var
> > > (databases that are no longer in use) that can be pitched.
> > 64GB should be plenty, depending on usage of course. A full /var is a
> > worry, especially if it runs short of room for logging.
I did makethe latter point, at least, from experience :)
> When fsck is running, it usually happens in a mode where only /
> is mounted read-only, and all other file systems (such as /usr
> or /var) are not. So I'd say that fsck doesn't do logging
> somewhere into /var/log because it doesn't exist at that time.
> Single user mode is a state of heavily reduced system functionality,
> but usually sufficient for solving file system problems.
It's true that /var/log/* can't be written then, but it's all buffered
in dmesg, saved to messages [& console.log] once syslogd starts. From
single user you can say, '# dmesg >/root/dmesg.save' or a scratch disk.
> > > > Also, does 'du /usr/lost+found' reveal anything?
> > >
> > > It was full of stuff /usr/src, best I could make out. Not sure why it
> > > all ended up in there.
> > Well at least /usr/src is easily replaced. Might be worth just deleting
> > all that, though of course you need a read-write mount first .. perhaps
> > after booting from a memstick or live CD?
> Which is still risky, assuming that the file system has not
> been marked clean.
Absolutely. I'm assuming that at this stage the choice is to newfs /usr
and restore backups, unless some magic spell turns up. Once apparently
losing or damaging '..' from anywhere, you're pretty much in trouble.
Paul, another question: with /usr unmounted, is there anything in /usr ?
> > You might also check (before and after deleting anything) that /usr
> > isn't running short of inodes (df -hi)?
> Good suggestion.
Only what I read; newfs defaults have always been generous for my usage.
> > Just stabbing in the dark .. scrambled filesystems are the pits!
> And a good occassion to read more about UFS (McKusick et al.) - to
> develop a better understanding of what's happening. :-)
Good suggestion :) I envy people who've got the time these days ..
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