3.6 Upgrading from OES 2 to OES 11 SP3

Consider the following issues when upgrading from OES 2 to OES 11 SP3:

3.6.1 Parameter Settings

When you upgrade the server from OES 2 to OES 11 SP3, all NSS-related parameter settings remain the same as they were before the upgrade. For example, server-level, pool, and volume settings are not modified. All future pools and volumes are created with the default settings for OES 11 SP3.

3.6.2 Read Ahead Blocks Setting

The Read Ahead Blocks parameter specifies the number of data blocks that NSS reads ahead for any open file on which read operations are ongoing in the specified server. Its default setting is 16. After upgrading to OES 11 SP3, if you experience read performance problems with an NSS volume, check the volume’s Read Ahead Blocks parameter setting.

You can view or modify the Read Ahead Blocks value by using NSSMU as follows:

  1. In NSSMU, select Volumes to view a list of volumes.

  2. Select the volume, then press Enter to view its Volume Properties list.

  3. Press the arrow keys to go to the Read Ahead Count in Blocks parameter, then press Enter to access the setting.

  4. Type the new count value, then press Enter.

    Valid values are 0 to 1024 blocks, where a block is 4 KB. However, a count of 128 is the practical maximum value. Read-ahead block counts higher than 128 can starve other system components for memory or buffers, which can impair performance or cause the system to hang. As the number of concurrent connections to unique files increase, you should reduce the number of read-ahead blocks.

  5. Press the arrow keys to go to Apply, then press Enter to save and apply the new setting.

You can also modify the value by using the Read Ahead Blocks switches in the NSS Console. For information, see Section A.30, Read Ahead Blocks and Allocate Ahead Blocks Commands.

For more information, on updating see For Servers with EVMS and LVM on the System Device in the OES 11 SP3: Installation Guide.