Improving Disk Reads

On a server that is read-intensive, the following procedures can improve the speed of disk reads.

• Changing Concurrent Disk and Directory Writes for Faster Reads.
• Changing the Turbo File Allocation Table (FAT) Wait Time for Faster Reads.

For instructions on using MONITOR, see MONITOR in Utilities Reference..

Changing Concurrent Disk and Directory Writes for Faster Reads

Use this procedure if your server is slow to respond to read requests.

NOTE:  This procedure requires that you decrease the values of the Maximum Concurrent Disk Cache Writes parameter and the Maximum Concurrent Directory Cache Writes parameter. Although decreasing these values increases the speed of read requests, it might decrease the speed and efficiency of write requests.

1. From the MONITOR Available Options, select Server Parameters > File Caching.

   NOTE:  You can also set file caching parameters with the SET command in MONITOR.

2. Decrease the value of Maximum Concurrent Disk Cache Writes.

   If the parameter is currently set to the default value of 50, try setting the value to 10.

3. Press ESC to return to the list of categories and then select Directory Caching.

   A list of Directory Caching parameters appears in the upper window.

4. Decrease the value of Maximum Concurrent Directory Cache Writes.

   If the parameter is currently set to the default value of 10, try setting the value to 5.

5. Increase the value of Directory Cache Buffer Non Referenced Delay.

   This parameter specifies how long a directory entry must be cached before it can be overwritten. Increasing this value causes the system to allocate more directory cache buffers and thus speeds up directory access.

   If the parameter is currently set to the default value of 5.5 seconds, try setting the value to 60 seconds.

6. Press Esc until you return to Available Options.

Changing the Turbo File Allocation Table (FAT) Wait Time for Faster Reads

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, use this procedure to increase the time the index is kept in memory.

1. From the MONITOR Available Options, select Server Parameters > File System. For instructions on using MONITOR, see MONITOR in Utilities Reference..

   A list of File System Parameters displays in the upper window.

   NOTE:  You can also set file system parameters with the SET command in MONITOR.

2. Scroll down the File System Parameters list to Turbo FAT Re-Use Wait Time.

   The scroll thumb to the right indicates that you can use the arrow keys to scroll the list.

3. Increase the value of FAT Re-Use Wait Time.

   You must specify the value in seconds.

   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). The changed value is now persistent.

4. Press Esc until you return to Available Options.