NAME
hfs_revra_per_disk — maximum HFS file system blocks to be read in one read-ahead operation when sequentially reading backwards
DESCRIPTION
This tunable defines the maximum number of file system blocks
to be read in one read-ahead operation when sequentially reading backwards.
Who Is Expected to Change This Tunable?
HP Field engineers, but not customers directly.
When Should the Value of This Tunable Be Raised?
The value of this tunable should be increased if there is a
large number of reverse sequential file I/O on file systems with small file
system block size.
What Are the Side Effects of Raising the Value?
The system will consume more memory in the buffer cache.
When Should the Value of This Tunable Be Lowered?
The value of this tunable should be lowered when there is a smaller number of
reverse sequential file I/O on files systems with large
file system block size.
What Are the Side Effects of Lowering the Value?
The file throughput rate will be decreased.
What Other Tunables Should Be Changed at the Same Time?
None.
WARNINGS
All HP-UX kernel tunable parameters are release specific.
This parameter may be removed or have its meaning changed in
future releases of HP-UX.
Installation of optional kernel software, from HP or other vendors,
may cause changes to tunable parameter values. After installation,
some tunable parameters may no longer be at the default or
recommended values. For information about the effects of
installation on tunable values, consult the documentation
for the kernel software being installed.
For information about optional kernel software that was
factory installed on your system, see
HP-UX Release Notes
at
http://docs.hp.com.
AUTHOR
hfs_revra_per_disk
was developed by HP.
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