Attention

Set this parameter to ON only if you are absolutely sure your backup strategy enables you to restore a file which has been deleted.

5.3.1.11 Enable Disk Read After Write Verify

In NetWare, this read-after-write verify capability complements the hot fix function. This allows the system to prevent any file from being written to a bad disk block by attempting to read the data after it has been written to disk. NetWares read-after-write capability and hot fix function are implemented in software.

This value is normally determined by the device driver and normally defaults to ON.

On all IBM disk controllers, this read-after-write operation is completed at the hardware level. Leaving this parameter ON will degrade disk subsystem performance.

You can modify this value using the set command in the AUTOEXEC.NCF file as follows:

SET ENABLE READ AFTER WRITE VERIFY=VALUE

NetWare 3.12 and 4.1: Default = ON

This value can be viewed and set by using the MONITOR.NLM utility.

5.3.2 Network Subsystem

Poor network design or network traffic congestion can have an adverse effect on the server and workstation performance. The following sections highlight some important factors to consider in order to optimize the performance of the network subsystem.

5.3.2.1 LAN Device Driver Efficiency

The device driver is responsible for communicating between the NetWare operating system and the LAN adapter hardware. It assembles and disassembles the IPX packets on the LAN as they come through the driver.

The NetWare device drivers produced by IBM and Novell are checked for performance before they are released. If they do not perform better (or at least as fast as the old driver), they are not released. Therefore, always use the latest device driver unless otherwise stated.

Some of the software LAN adapter device drivers are written with command line options which can be used to change the behavior of the device driver. For example, some third party manufacturers have a command line option to switch the early token release option on or off. This option is available on most 16 Mbps token-ring adapters.

182NetWare Integration Guide

Page 194
Image 194
IBM SG24-4576-00 manual Network Subsystem, Enable Disk Read After Write Verify, LAN Device Driver Efficiency