Ext3 filesystem goes read-only without the underlying storage reporting errors

  • 3605538
  • 27-Feb-2008
  • 08-Nov-2012

Environment

SUSE Linux Enterprise Server 10, prior to Support Pack 2
SUSE Linux Enterprise Desktop 10, prior to Support Pack 2
Novell Open Enterprise Server 2 (OES 2)

Ext3 filesystem

Situation

An ext3 filesystem is remounted read-only by the kernel.
No errors are reported from the storage layer underlying the affected filesystem.

Resolution

Status (Last updated: 2008-07-07)

This issue is fixed as of SLE10 SP2. Refer to TID 7000387 - How to update to SLES/SLED 10 SP2 for details on the process of updating to SP2.

For systems which cannot be updated to SLE10 SP2 (e.g. systems running Open Enterprise Server 2 GA), this issue is fixed as of kernel version 2.6.16.54-0.2.8 which is available as an on-line update.

Workaround


When a kernel update (as discussed above) is not an option, the problem can als be worked around by explicitly disabling barrier support for the affected filesystems, e.g. by specifying
barrier=0
in /etc/fstab's mount options field for the affected filesystems.

Additional Information

Root cause

Error handling code in the ext3 filesystem code is not properly handling the case where a device has stopped to accept barrier requests, which can happen with software RAID devices, LVM devices, device-mapper devices and with third party multipathing software like EMC PowerPath.

Background

For background on I/O barriers, please refer to KB 3907838 -JBD error message "barrier-based sync failed".

Related issues


Pre-service pack 1 installations can be affected by an issue with similar symptoms. That issue is covered in KB 3735930 - Filesystem goes read-only without the underlying storage reporting errors.

VMware guest installations can also be affected by an issue with similar symptoms. That issue is covered in KB 7005154 - Filesystem goes read-only in VMware.