1.36.  device-mapper-multipath

there was a race condition in the shutdown code for multipathd wherein a lock could be destroyed before all threads were finished using it. This could cause the machine to become unresponsive on multipathd shutdown. The multipathd daemon now waits for all threads to finish using the lock before destroying it, thus removing the race and resolving the issue.

when adding a new multipath-capable block device, a race condition existed between the multipathd daemon and udev to multipath the new device. If udev--through multipath--updated the multipath devices first, then the multipathd daemon would not use the device-specific configurations for the device when it started monitoring the path. With this update, multipathd now correctly configures the device, even when udev notices it first, thus resolving the issue.

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.

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.

Default configurations were added for the Compellent Storage Center and the IBM DS3200, DS3300, DS4700, and DS5000.

It is now possible to set the verbosity level for the multipath and multipathd commands in /etc/multipath.conf.

The TUR path checker retries on more transient errors, so that multipathd will not fail a path due to a transient error.

There is a new priority callout mpath_prio_intel to support the Intel Modular Server.

There is now a multipath.conf.5 man page that explains the /etc/multipath.conf configuration file.