Dell PERC 4/SC - Manual (Page 12)

1. Shut down and turn off the system as well as all peripherals attached to the system.
2. Remove the system cover.
See the system Installation and Troubleshooting Guide for detailed instructions.
3. Label the SCSI connectors that connect to the 3/DC, 3/DCL and 3/SC controller connectors.
4. Disconnect the connectors attached to the PERC 3/DC, 3/DCL and 3/SC controller and remove the controller from the system.
See the system's Installation and Troubleshooting Guide for instructions.
5. Install the PERC 4/DC or 4/SC controller and install the SCSI cables you removed in step 4.
See the documentation provided with the controller kit.
6. Close or replace the system cabinet cover.
7. Reconnect the system and peripherals to their power sources.
8. Boot the system.
The configuration data on the hard drive is used automatically if there is configuration mismatch (assuming the new controller has no configuration).
9. Microsoft detects the new hardware and prompts you for the new driver diskette that contains the driver for PERC 4/DC or PERC 4/SC.
Changing the Write Policy
If your new PERC 4/DC controllers have different battery backup settings than the previous controllers, you must change the write policy of the logical drive to
obtain additional performance improvements or avoid data corruption in the event of power loss.
For example, PERC 3/SC and PERC 3/DCL controllers do not include a battery backup unit, while the PERC 4/DC and PERC 3/DC do have a battery backup unit.
If you are upgrading from a PERC 3/SC to a PERC 4/DC, you should change the write policy from Write-Through to Write-Back for additional performance
improvements.
If you are upgrading a PERC 3/DCL to a PERC 4/DC with the same battery backup settings, you do not need to change the write policy.
To change the write policy settings, perform the following steps:
1. From the PERC BIOS Configure Utility, select Object —> Logical Drive menu.
2. Select the logical drive and press <Enter>.
3. Select View/Update Parameters and press <Enter>.
4. Select Write Policy and press <Enter>.
5. Select WrBack or WrThru according to the battery unit setting.
If the new adapter does not include the battery backup unit, select WrThru. Otherwise, select WrBack.
6. Press <Esc> as many times as necessary to return to the Logical Drive Menu.
CAUTION: If the SCSI connectors are not properly identified with their channel identification, the PERC 4 firmware may be unable to convert to
the correct logical drive configuration (performed in the next procedure.)
NOTE: If you have configured a RAID 5 system with more than four physical drives, the disk activity LED blinks after the BIOS configuration is
complete. This is an indication of normal background consistency checking being performed by the PERC 4 controllers. Consistency checking could
take hours to complete, depending on the size of the logical drives. The server is usable, although I/O response may be slow. Performance should
be back to normal after consistency checking.