System information

General System Resource Management 119
To turn off access time updates, mount the file system with the noatime option. To
do so, either edit /etc/fstab directly, or use the Fstab Options dialog when editing
or adding a partition with the YaST Partitioner.
9.3.3 Prioritizing Disk Access with ionice
The ionice command lets you prioritize disk access for single processes. This en-
ables you to give less I/O priority to non time-critical background processes with
heavy disk access, such as backup jobs. On the other hand ionice lets you raise I/O
priority for a specific process to make sure this process has always immediate access
to the disk. You may set the following three scheduling classes:
Idle
A process from the idle scheduling class is only granted disk access when no oth-
er process has asked for disk I/O.
Best effort
The default scheduling class used for any process that has not asked for a specific
I/O priority. Priority within this class can be adjusted to a level from 0 to 7 (with
0 being the highest priority). Programs running at the same best-effort priority
are served in a round-robin fashion. Some kernel versions treat priority within the
best-effort class differently—for details, refer to the ionice(1) man page.
Real-time
Processes in this class are always granted disk access first. Fine-tune the priority
level from 0 to 7 (with 0 being the highest priority). Use with care, since it can
starve other processes.
For more details and the exact command syntax refer to the ionice(1) man page.