4.9. Configuring atime Updates
Each file inode and directory inode has three time stamps associated with it:
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ctime — The last time the inode status was changed
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mtime — The last time the file (or directory) data was modified
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atime — The last time the file (or directory) data was accessed
If atime updates are enabled as they are by default on GFS and other Linux file systems then every time a file is read, its inode needs to be updated.
Because few applications use the information provided by atime, those updates can require a significant amount of unnecessary write traffic and file-locking traffic. That traffic can degrade performance; therefore, it may be preferable to turn off atime updates.
Two methods of reducing the effects of atime updating are available:
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Mount with noatime
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Tune GFS atime quantum
