Home > Storage > PowerVault > Guides > Dell PowerVault ME5 Series and Linux > IO scheduler
Some applications might recommend a different I/O scheduler than the default scheduler on the Linux operating system. Consult the application documentation for the proper selection.
Query each volume for the current scheduler setting:
# grep -E "*" /sys/block/sd*/queue/scheduler
/sys/block/sdb/queue/scheduler:[none] mq-deadline kyber bfq
/sys/block/sdc/queue/scheduler:[none] mq-deadline kyber bfq
/sys/block/sdd/queue/scheduler:[none] mq-deadline kyber bfq
/sys/block/sde/queue/scheduler:[none] mq-deadline kyber bfq
To set the I/O scheduler persistently, create an udev rule that updates the devices. The following example shows setting the mq-deadline I/O scheduler on all /dev/sd* devices. The udev rule file is created in /etc/udev/rules.d/99-me5.rules.
# cat /etc/udev/rules.d/99-me5.rules
ACTION=="add|change", KERNEL=="sd*", RUN+="/bin/sh -c '/bin/echo mq-deadline > /sys$env{DEVPATH}/queue/scheduler'"
# udevadm control --reload-rules
# udevadm trigger