This section describes configuration procedures that might improve your filer's performance.
An extremely large directory file can use up most of the filer's CPU cycles when a user enters an ls command in the directory. The limit on directory file size is set by the options wafl.maxdirsize command. The default limit, 10 MB, should prevent the system from hanging. A directory of this size accommodates approximately 300,000 files with short file names.
The wafl.maxdirsize option takes the maximum number of kilobytes as its argument. When you reset the maximum directory size, the argument that you supply is rounded up to the next highest 4K boundary. If a user tries to create a file that would cause the directory to grow larger than the specified size limit, the user's command fails.
To balance network traffic among different interfaces, attach multiple interfaces on the filer to the same physical network. For example, if two Ethernet interfaces on the filer named toaster are attached to the same network where four clients reside, specify in /etc/fstab on client1 and client2 that these clients mount from toaster-0:/home. Specify in /etc/fstab on client3 and client4 that these clients mount from toaster-1:/home. This scheme can balance the traffic among interfaces if all clients generate about the same amount of traffic.
The filer always responds to an NFS request by sending its reply on the interface on which the request was received.
If your applications do not depend on having the correct access time for files, you can disable the update of access time (atime) on an inode when a file is read. To prevent updates, turn the no_atime_update option On. Consider turning this option On if your filer has extremely high read traffic, for example, on a news server used by an Internet provider, because it prevents inode updates from contending with reads from other files.
Caution: If you are not sure whether your filer should maintain an accurate access time on inodes, leave this option at its default, Off, so that the access time is updated.
Turning the nfs.big_endianize_fileid option On improves performance on directory lookups for clients that use the file ID in the file handle as a hash key in certain ways. Enable this option if your NFS clients are mainly running HP-UX or IRIX.
Note: If you turn the big_endianize_fileid option On, all NFS clients that have mounted directories from the filer must unmount and remount them; otherwise, they get "stale file handle" errors on all references to files already opened on the filer until they unmount and remount all directories.
If the file access patterns of your clients are random (nonsequential), turning minimal read-ahead On might improve performance. By default, the filer uses aggressive read-ahead, which enhances sequential access, which is more commonly used by UNIX clients and applications. To specify minimal read-ahead, turn the minra option On. By default, the option is Off and the filer does very aggressive read-ahead.
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Part No. 210-02334
File: stats7.htm
Last updated: 04/26/99 08:11:56