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Change-Id: Ib4101fdb37cf91a547974216425e4a005392d988 Reviewed-on: http://gerrit.openafs.org/10413 Reviewed-by: Derrick Brashear <shadow@your-file-system.com> Tested-by: Derrick Brashear <shadow@your-file-system.com>
81 lines
1.9 KiB
Plaintext
81 lines
1.9 KiB
Plaintext
=head1 NAME
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fs_precache - Set precache size
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=head1 SYNOPSIS
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=for html
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<div class="synopsis">
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B<fs precache> S<<< B<-blocks> <I<size in 1K blocks>> >>>
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[B<-help>]
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B<fs p> S<<< B<-b> <I<size in 1K blocks>> >>>
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[B<-h>]
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=for html
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</div>
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=head1 DESCRIPTION
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The B<fs precache> command configures to what degree the Cache Manager will
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attempt to prefetch cache blocks when an application opens a file for reading.
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If this behavior is enabled, whenever a file is opened for reading, the Cache
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Manager will immediately initiate an asynchronous fetch request for that file.
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This fetch request will fetch the configured amount of data for that file, and
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store the data in the cache. In some scenarios, this can improve performance.
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Note that this prefetching behavior is done by the Cache Manager itself. The
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underlying Operating System may also perform its own prefetching behavior,
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depending on various settings or application hints.
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This command was introduced in OpenAFS 1.5.37.
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=head1 OPTIONS
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=over 4
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=item B<-blocks> <I<size in 1K blocks>>
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Specifies how much data to prefetch for each applicable file, in 1024-byte
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blocks. Specify 0 to disable prefetching behavior. By default, prefetching is
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disabled.
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=item B<-help>
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Prints the online help for this command. All other valid options are
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ignored.
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=back
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=head1 OUTPUT
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If the specified precache size has been set successfully, the following message
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will be printed:
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New precache size set.
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=head1 EXAMPLES
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The following command configures the Cache Manager to prefetch the first 100
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kilobytes of any file that's opened for reading:
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% fs precache -blocks 100
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New precache size set.
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=head1 PRIVILEGE REQUIRED
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The issuer must be logged in as the local superuser C<root>.
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=head1 SEE ALSO
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L<afsd(8)>
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=head1 COPYRIGHT
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Copyright 2013 Sine Nomine Associates
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This documentation is covered by the BSD License as written in the
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doc/LICENSE file. This man page was written by Andrew Deason for
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OpenAFS.
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