Ext3 users - Jun 2006 - Errors on EXT3 on RHEL3, Can we use e2fsprogs 1.36?

SUMMARY

We are getting many ``Free blocks count wrong for group'' errors when
running e2fsck on a 245-GB ext3 filesystem.  This is when the file
system is cleanly unmounted on a relatively quiet system to do a
resize.  From reading other messages here, my suspicion is that this
is because we have e2fsprogs 1.32.

Questions:

* Should we use e2fsck/e2fsprogs 1.36 and will that probably address this
  problem?

* Is e2fsprogs 1.36 compatible with EXT3 2.4-0.9.19 on RHEL3?


DETAILS

Kernel:  Linux ****** 2.4.21-37.0.1.ELsmp #1 SMP Wed
         Jan 11 18:44:17 EST 2006 i686 i686 i386 GNU/Linux

FS:   EXT3 FS 2.4-0.9.19, 19 August 2002 on sd(8,1), internal journal

----------------------------------------------------------------------
dumpe2fs 1.32 (09-Nov-2002)
...
Filesystem revision #:    1 (dynamic)
Filesystem features:      has_journal dir_index filetype
needs_recovery sparse_super
----------------------------------------------------------------------

As far as I can tell every group is enumerated in the e2fsck output
(see below).  We've unmounted, run e2fsck and extended the filesystem
several times and we saw these errors every time.  Each time we ran
e2fsck on the fs.

This filesystem stores email for  the Cyrus IMAP software.  However,
user trees of sometimes large Berkeley mbox files are copied to this
filesystem, converted to Cyrus message files, then deleted.  So large
collections of large files are created and deleted in a rather short
period of time.

The mounted device is an LVM logical volume and the back end storage is
EMC.

Thanks.

Ken Guyton
Emory University



Output of e2fsck:

----------------------------------------------------------------------
e2fsck 1.32 (09-Nov-2002)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 3A: Optimizing directories
Optimizing directories:  163843 196610 491522 589826 688143 720898...
Pass 4: Checking reference counts
Pass 5: Checking group summary information
Block bitmap differences:  -(12--1033) -(32780--33801) -(65537--65546)...
Fix<y>? yes

Free blocks count wrong for group #0 (6582, counted=7604).
Fix<y>? yes

Free blocks count wrong for group #1 (14316, counted=15338).
Fix<y>? yes

Free blocks count wrong for group #2 (30603, counted=30613).
Fix<y>? yes

...

Free blocks count wrong for group #1006 (13, counted=23).
Fix<y>? yes

Free blocks count wrong for group #1007 (0, counted=10).
Fix<y>? yes

Free blocks count wrong for group #1008 (0, counted=10).
Fix<y>? yes

Free blocks count wrong for group #1009 (0, counted=10).
Fix<y>? yes

Free blocks count wrong (3497725, counted=3523005).
Fix<y>? yes

y
/dev/mailvg/mailvol: ***** FILE SYSTEM WAS MODIFIED *****
/dev/mailvg/mailvol: 2461667/39714816 files (2.1% non-contiguous),
36191811/39714816 blocks
----------------------------------------------------------------------

Hi Ken,

On Thu, 1 Jun 2006, Ken Guyton wrote:
> * Should we use e2fsck/e2fsprogs 1.36 and will that probably address this
> problem?
That'd be a good idea, given the old version you're using atm.
> * Is e2fsprogs 1.36 compatible with EXT3 2.4-0.9.19 on RHEL3?
yes.

Are you running fsck on a (ro-)mounted fs? If yes and the errors persist, 
please try to unmount the fs.

Christian.
-- 
BOFH excuse #38:

secretary plugged hairdryer into UPS

> Are you running fsck on a (ro-)mounted fs? If yes and the errors 
persist,
 > please try to unmount the fs.

No, we've always unmounted the fs before trying fsck.

Thanks!

Ken Guyton

On Thu, Jun 01, 2006 at 01:39:55PM -0400, Ken Guyton
wrote:
> SUMMARY
> 
> We are getting many ``Free blocks count wrong for group'' errors
when
> running e2fsck on a 245-GB ext3 filesystem.  This is when the file
> system is cleanly unmounted on a relatively quiet system to do a
> resize.  From reading other messages here, my suspicion is that this
> is because we have e2fsprogs 1.32.
I'm not certain that the problem is caused by e2fsprogs 1.32, but it
is a very old version of e2fsprogs.  In general though e2fsprogs is
quite careful about backwards compatibility, so it should be safe to
use the latest e2fsprogs 1.39 on an RHEL3 system.  You will have to
compile it yourself from source, though.  (And there have been quite a
lot of bugs fixed between 1.36 and 1.39)

						- Ted