Red Hat ENTERPRISE 5.4 RELEASE NOTES, Manual

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Chapter 1. Package Updates
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Updated device-mapper-multipath packages that fix a bug are now available.
The device-mapper-multipath packages provide tools to manage multipath devices by giving the
device-mapper multipath kernel module instructions on what to do, as well as by managing the
creation and removal of partitions for device-mapper devices.
• multipath must be able to open a file descriptor for each path that it monitors, plus 32 other file
descriptors. By default, multipath can open 1024 file descriptors, which is sufficient for it to monitor
992 paths. If multipath is not able to open all the file descriptors that it needs, the multipath daemon
will not function correctly, and in Red Hat Enterprise Linux 5.3, this situation exposes a kernel
memory leak that can cause a system to stop responding. Previously, multipath would not warn
users that it could not open enough file descriptors. Now, when multipath runs out of file descriptors,
it prints an error message. System administrators can allow multipath to open more file descriptors
by setting "max_fds" in the multipath.conf file to a sufficiently high number, or by setting "max_fds"
to "max" to allow multipath to open as many file descriptors as the system allows.
Users are advised to upgrade to these updated device-mapper-multipath packages, which resolve this
issue.
1.36.4. RHEA-2009:1377: bug-fix and enhancement update
Updated device-mapper-multipath packages that fix several bugs and add various enhancements are
now available.
The device-mapper-multipath packages provide tools to manage multipath devices using the device-
mapper multipath kernel module.
This update applies the following bug fixes:
• Occasionally multipathd was ignoring a device's hardware type when configuring it after a path was
added.
• Multiple documentation errors were fixed.
• Multipathd would occasionally hang or crash while shutting down.
• Multipath would always return a failure exit code when removing a device with multipath -f/-F.
• Multipathd wouldn't free its resources when it failed to execute a callout.
• Multipathd would always return a success exit code for interactive commands, even if the command
failed or was invalid.
• The mpath_prio_alua pritority callout was failing on some setups because a buffer was too small.
• Multipathd was holding mount points in the /etc directory busy, even after they were unmounted.
• Multipath and multipathd were racing to create the mulitpath devices for newly added block devices.
This was causing device creation to take a long time on some systems, and could even cause
devices to have incorrect configurations.
This update adds the following enhancements:
• Default configurations were added for the Compellent Storage Center and the IBM DS3200,
DS3300, DS4700, and DS5000.