RHBA-2009:1382 - Bug Fix Advisory

Topic

An updated mdadm package that fixes several bugs and adds an enhancement is
now available.

Description

mdadm is used to create, manage, and monitor Linux MD (software RAID)
devices. It provides similar functionality to the raidtools package.

This updated package fixes the following bugs:

• the Linux software raid stack supports data scrubbing (reading disks in

the raid array and looking for bad sectors, and when bad sectors are found
using information from other disks or from parity to rewrite the bad
sectors with good data). However, the mdadm package did not make use of
this functionality. This package adds a cron job to /etc/cron.weekly to
check disks for bad sectors and repair them when found. (BZ#233972)

• the mdadm man page contained several typos and was not clear on the

proper usage of a number of mdadm options. The typos have been removed and
notes and clarifications have been added so that the man page now better
reflects the proper usage and limitations of the mdadm command. (BZ#434670,
BZ#434671, BZ#489476)

• mdadm did not recognize the "-N" and "-Y" short options, although it

recognized their long equivalents ("--name" and "--export") and they were
listed as valid in mdadm --help. Mdadm now recognizes these short options.
(BZ#478977)

• a new raid-check script (see the enhancement note below) attempted to

check arrays that were not checkable. The script first retrieved a list of
active arrays from /proc/mdstat then attempted to write "check" to the
sync_action element of each array's sysfs entry. Non-redundant arrays (such
as linear and raid0 arrays) do not have a sync_action entry in sysfs,
however. Note: this did not prevent the script from checking arrays that
could be checked but did cause cron job output errors to be e-mailed to the
system administrator. The raid-check script now checks for a sync_action
element in sysfs before writing to it. (BZ#513473)

This update also adds the following enhancement:

• with this update mdadm has new functionality to enable "data scrubbing"

on redundant arrays. Data scrubbing looks for bad sectors on drives in
redundant arrays and fixes the bad sectors using data from other drives to
reconstruct sectors that return read errors. Note: data scrubbing is on by
default in this new package. It runs once per week and may cause some
performance degradation while it is running. If users wish to disable this
feature for performance reasons, or if they wish to control what type of
check is performed on arrays, or which arrays to check at all, edit the
file /etc/sysconfig/raid-check. Details of how to set options are included
in the file as comments. (BZ#513200)

This package also updates the upstream source base from mdadm-2.6.4 to
mdadm-2.6.9. For a list of the changes and bug fixes included via this
upstream update, please read the various ANNOUNCE-* files located in
/usr/share/doc/mdadm-2.6.9 after installing the updated mdadm-2.6.9
package.

All mdadm users are advised to upgrade to this updated package, which
resolves these issues and adds this feature.

Solution

Before applying this update, make sure that all previously-released
errata relevant to your system have been applied.

This update is available via Red Hat Network. Details on how to use
the Red Hat Network to apply this update are available at
http://kbase.redhat.com/faq/docs/DOC-11259

Affected Products

• Red Hat Enterprise Linux Server 5 x86_64
• Red Hat Enterprise Linux Server 5 ia64
• Red Hat Enterprise Linux Server 5 i386
• Red Hat Enterprise Linux Workstation 5 x86_64
• Red Hat Enterprise Linux Workstation 5 i386
• Red Hat Enterprise Linux Desktop 5 x86_64
• Red Hat Enterprise Linux Desktop 5 i386
• Red Hat Enterprise Linux for IBM z Systems 5 s390x
• Red Hat Enterprise Linux for Power, big endian 5 ppc
• Red Hat Enterprise Linux Server from RHUI 5 x86_64
• Red Hat Enterprise Linux Server from RHUI 5 i386

Fixes

• BZ - 233972 - Enhancement request to Software RAID to do Data Scrubbing
• BZ - 434670 - mdadm.8 typos
• BZ - 434671 - mdadm.8 says "mdadm -G -x" is valid, but it is rejected.
• BZ - 478977 - mdadm does not recognize "-N" and "-Y" options
• BZ - 513473 - raid-check script attempts to check arrays that aren't checkable

CVEs

(none)

References

(none)