Improving I/O performance on Red Hat Enterprise Linux hosts

You can improve I/O performance on Red Hat Enterprise Linux 6 and 7 by using the tuned-admcommand in the enterprise-storage profile. You can use the virtual-guest profile for Red Hat Enterprise Linux as a guest virtual machine. Using these settings can result in marked improvement in throughput and latency on clustered Data ONTAP.

About this task

You can use the enterprise-storage profile for configurations where LUNs from enterprise storage arrays are used. It enables a number of performance fine-tuning measures such as switching the I/O scheduler to deadline from the default cfq, as well as increasing the read-ahead, setting the CPU governor to performance mode, and so on.

The man page for the tuned-adm command contains syntax, default value, and other usage.

Steps

Verify that the currently active profile is default: tuned-adm active

Current active profile: default
Service tuned: enabled, running
Service ktune: enabled, running

Set the profile to enterprise-storage: tuned-adm profile enterprise storage

Example

The output changes based on the number of LUNs presented to the host, and might differ from what this example shows:

Stopping tuned:                                     [  OK  ]
Switching to profile 'enterprise-storage'
Applying deadline elevator: dm-0 dm-1 dm-2 dm-3 sda sdb sdc[  OK  ] sdf sdg sdh sdi sdj sdk
Applying ktune sysctl settings:
/etc/ktune.d/tunedadm.conf:                                [  OK  ]
Calling '/etc/ktune.d/tunedadm.sh start':                  [  OK  ]
Applying sysctl settings from /etc/sysctl.conf
Starting tuned:                                            [  OK  ]

Verify that the profile was changed: tuned-adm active

Current active profile: enterprise-storage
Service tuned: enabled, running
Service ktune: enabled, running