"io_setup failed" in RedHat and Dell MD12XX - MP1280 - PowerVault - Dell Unofficial Support Forum

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Guru9

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"io_setup failed" in RedHat and Dell MD12XX - MP1280
« on: June 09, 2016, 04:46:54 AM »
Issue

Code: [Select]
[b]$ multipath -ll
io_setup failed
io_setup failed
io_setup failed
io_setup failed
io_setup failed
360a98000486e61396c344f4641434b50dm-19
[size=28G][features=1 queue_if_no_path][hwhandler=0]
_ round-robin 0 [prio=0][active]
_ 4:0:0:0 sdbr 68:80  [active][faulty]
_ 3:0:0:0 sdb 8:16  [active][faulty]
_ round-robin 0 [prio=0][enabled]
_ 3:0:1:0 sdaj 66:48  [active][faulty]
_ 4:0:1:0 sdcz 70:112 [active][faulty]
[/b]
Resolution

This message indicates that there are no more avialable asynchronous I/O contexts available in the system. The direction path checker needs to allocate an asynchronous I/O (aio) context for each path that it must monitor. The number of active aio contexts system wide is limited via the fs.aio-max-nr sysctl parameter. This parameter has a default value which is sufficient for most environments. For workloads that make significant use of the aio interface however this limit may be insufficient leading to the errors shown above.
The value of the sysctl can be increased either temporarily via the /proc file system or persistently by modifying the file "/etc/sysctl.conf".

  • To temporarily increase the available number of aio contexts:

echo N > /proc/sys/fs/aio-max-nr

Replace N with a suitable value.
For a MD1280, try doubling the existing value.

  • To permanently increase the available number of aio contexts add the following line to "/etc/sysctl.conf:"

fs.aio-max-nr = <value>

Following this change the new value will be applied at the next system boot or when the administrator runs the following command:

sysctl -p /etc/sysctl.conf