Re: Serious ext2fs problem

Chris Adams (cadams@ro.com)
Tue, 31 Dec 1996 13:21:15 -0600 (CST)

Once upon a time, Stephen C. Tweedie wrote
> In article <199612311454.IAA18638@sh1.ro.com> Chris Adams
> <cadams@ro.com> writes:
> > In my case, the filesystem error in questions is
>
> > EXT2-fs error (device 08:31): ext2_new_block: Free blocks count
> > corrupted for block group 546
>
> > This is on a 10 gig RAID 0 news spool (on a DPT 3224). The system is
> > running Linux 2.0.27 + the noatime patch and INN 1.4unoff4. When I run
> > e2fsck (1.04 that comes with RedHat 4.0 and 1.06 from tsx-11), no errors
> > are reported.
>
> Bad SCSI bus.
>
> This is almost certainly bad hardware, either the disk or the SCSI
> bus. I'd check your cables and try pushing the bus speed down to 5
> MHz. I have seen almost identical symptoms on a news server myself,
> and it turned out to be hardware. The reason you see the free blocks
> count message is just that this is one place that the kernel is in a
> position to do some self-checking; single-bit errors on the SCSI bus
> in other blocks won't normally be detected.

Once the errors start happening, they keep happening at the same place
over and over again. However, if I stop INN, umount the drive, mount
the drive, and start INN, everything is happy (I had it giving me the
above error twice everytime I tried to tell INN to "go"). Since I
umounted the drive and remounted it, it has been running just fine for
~24 hours. That doesn't seem like hardware to me.

> The fact that ext2fs can't find anything wrong does tend to suggest
> that it is indeed a bit-flip error when the blocks are coming off
> disk. It could also be a memory problem, but either way it's more
> symptomatic of system trouble rather than software trouble.
>
> In my case, switching the two disks (history and spool) onto separate
> controllers fixed the problem entirely.

I already have three 1 gig drives on an Adaptec 2940 (one for OS, swap,
and INN; one for history; and one for overviews). The news spool is
five 2 gig drives in a RAID 0 array on a DPT 3224. I have also had the
problem on the 1 gig drives drives, although not in the last week or two.
These are all drives, cables, and adapters that have worked fine for six
months. And yes, the case is well cooled (we have a thermometer on it
that I check every day or two), so I don't think the drives are all
going bad from heat at the same time.

-- 
Chris Adams - cadams@ro.com
System Administrator - Renaissance Internet Services