Novell Open Enterprise Server 2, Руководство системного администратора, Страница: 46 / 55

46 OES 2: NetWare Traditional File System Administration Guide
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7.2.2 Change the Turbo FAT Wait Time for Faster Reads of
Traditional Volumes
When a program randomly accesses a file that contains more than 64 file allocation table (FAT)
entries, the file system builds a turbo FAT index for the file so that the information in the file can be
accessed quickly.
The Turbo FAT Re-Use Wait Time parameter specifies how long a turbo FAT index remains in
memory after the indexed file is closed. When the turbo FAT index is in memory, files can be opened
and information accessed faster.
If network users frequently access files larger than 64 blocks, increase the value of FAT Re-Use Wait
Time , using “ SET ” in the OES 2: Utilities Reference . You must specify the value in seconds.The new
setting is persistent through a server reboot. If the parameter is currently set to the default value of
329.5 seconds (5 minutes 29.6 seconds), try setting the value to 600 seconds (10 minutes).
7.3 Improving Disk Writes for Traditional
Volumes
For a write-intensive server, the following procedures can improve the speed of disk writes:
Š
Section 7.3.1, “Increase the Number of Concurrent Writes,” on page 46
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Section 7.3.2, “Change Disk and Directory Caching for Faster Writes,” on page 47
Š
Section 7.3.3, “Turn Off Read-After-Write Verification,” on page 47
7.3.1 Increase the Number of Concurrent Writes
You can increase the speed and efficiency of disk cache writes by increasing the number of write
requests that can be executed at one time.
To determine whether you must increase the number of concurrent writes, first compare the number
of dirty cache buffers to the total number of cache buffers. These statistics are found on the General
Information screen in the
monitor
utility. Dirty cache buffers contain data that has not yet been
written to disk.
The ratio of dirty cache buffers to total cache buffers is an indicator of the efficiency of disk cache
writes. If the number of dirty cache buffers is greater than 70% of total cache buffers, increase the
number of concurrent write requests.
NOTE: Increasing the number of concurrent disk cache writes slows disk cache reads. You might
want to balance the speed of disk writes and reads to meet the needs of users. If your server’s
processing load is write-intensive, you can favor disk writes. If it is read-intensive, favor disk reads.
Increase the value of Maximum Concurrent Disk Cache Writes , using “ SET ” in the OES 2: Utilities
Reference . The new setting is persistent through a server reboot. If the parameter is currently at the
default value of 50, try increasing it to 100.