Red Hat GLOBAL FILE SYSTEM 4.6, Руководство пользователя

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9.1. Mount with
noatime
A standard Linux mount option,
noatime
, can be specified when the file system is mounted,
which disables
atime
updates on that file system.
Usage
mount -t gfs BlockDevice MountPoint -o noatime
BlockDevice
Specifies the block device where the GFS file system resides.
MountPoint
Specifies the directory where the GFS file system should be mounted.
Example
In this example, the GFS file system resides on the
/dev/vg01/lvol0
and is mounted on
directory
/gfs1
with atime updates turned off.
mount -t gfs /dev/vg01/lvol0 /gfs1 -o noatime
9.2. Tune GFS
atime
Quantum
When
atime
updates are enabled, GFS (by default) only updates them once an hour. The time
quantum is a tunable parameter that can be adjusted using the
gfs_tool
command.
Each GFS node updates the access time based on the difference between its system time and
the time recorded in the inode. It is required that system clocks of all GFS nodes in a cluster be
synchronized. If a node's system time is out of synchronization by a significant fraction of the
tunable parameter,
atime_quantum
, then
atime
updates are written more frequently. Increasing
the frequency of
atime
updates may cause performance degradation in clusters with heavy
work loads.
By using the
gettune
flag of the
gfs_tool
command, all current tunable parameters including
atime_quantum
(default is 3600 seconds) are displayed.
The
gfs_tool settune
command is used to change the
atime_quantum
parameter value. It
must be set on each node and each time the file system is mounted. (The setting is not
persistent across unmounts.)
Usage
Displaying Tunable Parameters
Chapter 4. Managing GFS
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