RHBA-2015:0367 - Bug Fix Advisory

Topic

Updated device-mapper-multipath packages that fix several bugs and add various
enhancements are now available for Red Hat Enterprise Linux 7.

Description

The device-mapper-multipath packages provide tools that use the device-mapper
multipath kernel module to manage multipath devices.

Bugs:

• Previously, multipath prioritizer functions had default timeouts that could

last up to 5 minutes. Consequently, if a multipath device failed after the
checker function claimed it was usable, the prioritizer became unresponsive.
Now, the timeouts of prioritizer functions can be set with the checker_timeout
option, thus fixing this bug. (BZ#1069811)

• When multipath had multiple paths per pathgroup, and the path selector was set

to round-robin, these paths could be ordered in a way that caused the I/Os to be
suboptimally distributed between controllers. Consequently, multipath load
balancing was not causing sufficient performance boost. This update enhances the
multipath ordering, and multipath load balancing now performances optimally.
(BZ#1080038)

• When a multipath device was reloaded outside of the multipathd daemon and if

existing paths were removed from the device, mutipathd still treated them as
belonging to the multipath device. Consequently, multipathd could try to access
a non-existent path_group and terminate unexpectedly. Now, multipathd correctly
disassociates removed paths, thus fixing the bug. (BZ#1080055)

• Previously, the user_friendly_names binding file in initramfs under certain

circumstances did not match the file in the normal system. A multipath device
could thus be assigned a user_friendly_name that conflicted with the name
already assigned by the normal system. Consequently, multipath in some cases
attempted to update an incorrect device, causing data corruption. With this
update, multipath checks whether device's paths user_friendly_name is already in
use, and assigns a new name if it is. (BZ#1086825)

• Previously, when multipath performed a rename, it did not reload the device

table as well. Consequently, if the user changed the device configuration, only
the name was changed on the first reload and the rest of the changes appeared
only after a second reload. With this update, multipath performs both the rename
and the table reload, thus fixing the bug. (BZ#1104605)

• If the multipathd daemon failed to add a path to the multipath device table,

it orphaned the path incorrectly, which caused multipath to treat the path as if
it belonged to a multipath device. Consequently, multipathd in some cases
repeatedly attempted to switch to a non-existent pathgroup. To fix this bug,
multipathd now oprhans paths correctly, thus fixing the bug. (BZ#1110007)

• When the "parted" utility created partitions on an existing multipath device,

it triggered race conditions with the kpartx utility to create the partitions,
which could cause device- or resource-busy errors. With this update, kpartx only
creates partition devices when the multipath device is activated, and it no
longer automatically creates partitions when "parted" is run on existing
multipath devices. (BZ#1148979)

Enhancements:

• A new multipath.conf option, deferre_remove, has been added. If set to

"yes", the multipathd daemon performs a deferred remove instead of a regular
remove when the last path device has been deleted. It defaults to "no".
(BZ#631009)

• A number of wildcard expressions have been added for the "multipathd show

paths format" command, which facilitate the association of multipath paths with
specific Fibre Channel hosts and targets as well as their ports, and thus allows
users to manage their storage configuration more effectively. (BZ#979474)

• The device-mapper-multipath utility has been enhanced to verify the

multipath.conf configuration file more reliably. Now, if multipath.conf contains
any unparseable lines, device-mapper-multipath reports an error and ignores
these lines. (BZ#1110013)

Users of device-mapper-multipath are advised to upgrade to these updated
packages, which fix these bugs and add these enhancements.

Solution

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

For details on how to apply this update, refer to:

https://access.redhat.com/articles/11258

Affected Products

• Red Hat Enterprise Linux Server 7 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.7 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.6 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.5 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.4 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.3 x86_64
• Red Hat Enterprise Linux Server - AUS 7.7 x86_64
• Red Hat Enterprise Linux Server - AUS 7.4 x86_64
• Red Hat Enterprise Linux Workstation 7 x86_64
• Red Hat Enterprise Linux Desktop 7 x86_64
• Red Hat Enterprise Linux for IBM z Systems 7 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.7 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.6 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.5 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.4 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.3 s390x
• Red Hat Enterprise Linux for Power, big endian 7 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.7 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.6 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.5 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.4 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.3 ppc64
• Red Hat Enterprise Linux for Scientific Computing 7 x86_64
• Red Hat Enterprise Linux Server from RHUI 7 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.7 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.6 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.5 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.4 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.3 x86_64
• Red Hat Enterprise Linux Server - AUS 7.6 x86_64
• Red Hat Enterprise Linux Server - AUS 7.3 x86_64
• Red Hat Enterprise Linux Server - TUS 7.7 x86_64
• Red Hat Enterprise Linux Server - TUS 7.6 x86_64
• Red Hat Enterprise Linux Server - TUS 7.3 x86_64
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 7.7 x86_64
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 7.6 x86_64
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 7.4 x86_64
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 7.3 x86_64

Fixes

• BZ - 1069584 - multipathd core dumped if the fast_io_fail_tmo is set but no value is provided.
• BZ - 1104605 - multipath devmap reload ignores other config changes when device is renamed
• BZ - 1109995 - multipath may hang if tur checker thread becomes unresponsive
• BZ - 1110007 - multipathd stuck trying to switch to group that does not exist
• BZ - 1159337 - multipathd crashes during iSCSI login and logout

CVEs

(none)

References

(none)