Verifying the Disk I/O Scheduler on Linux 7 Systems
Disk I/O schedulers reorder, delay, or merge requests for disk I/O to achieve better throughput and lower latency.
Linux has multiple disk I/O schedulers available, including
deadline
, noop
,
anticipatory
, and Completely Fair Queuing
(cfq
) on Oracle Linux 7, Red Hat Enterprise
Linux 7, and SUSE Linux Enterprise Server 12 systems. You should
consult with your storage vendor for the appropriate I/O scheduler
configuration to achieve best performance on Oracle Automatic
Storage Management (Oracle ASM).
In general, Oracle recommends that you set the I/O Scheduler to
deadline
for rotating storage devices
(HDDs) and to none
for non-rotating storage devices
such as SSDs and NVMe on Oracle Linux 7, Red Hat Enterprise Linux 7,
and SUSE Linux Enterprise Server 12 systems.
root
to verify the configured disk I/O scheduler
value.
cat /sys/block/${ASM_DISK}/queue/scheduler
noop [deadline] cfq
In this example, the default disk I/O scheduler is
deadline
and ASM_DISK
is a
rotational Oracle ASM disk device.
Note:
Contact your storage vendor for more information about how to configure I/O scheduler on Linux for your storage devices.