- ordered: It is the default mode. All data is forced directly out to the main file system prior to its meta-data being committed to the journal.
- writeback: Data ordering is not preserved, data may be written into the main file system after its metadata has been committed to the journal. This is rumored to be the highest-throughput option. It guarantees internal file system integrity, however it can allow old data to appear in files after a crash and journal recovery.
- journal: All data is committed into the journal prior to being written into the main file system.
defaults = (rw, suid, dev, exec, auto, nouser, async, and relatime)
- anticipatory (RHEL 4-5)
- Display the scheduler for disk:
- Change the scheduler online:
echo deadline > /sys/block/<disk>/queue/scheduler
- Change the scheduler globally (or write udev rules):
- Install the package:
yum install tuned; chkconfig tuned on; /etc/init.d/tuned start
- List all available profiles:
- Display the active profile:
- Change the profile (conf file - /etc/ktune.d/tunedadm.conf):
tuned-adm profile virtual-host
- Check mount options: