Learn About RAID Controller Module Diagnostics

Important: During the diagnostics, the  on which the tests are run will NOT be available for I/O.

The Diagnostics option allows a user to verify that a RAID controller module is functioning properly, through the use of various internal tests.

The Diagnostics use a combination of three different tests: Read Test, Write Test, and Data Loopback Test. You should run all three tests at initial installation and any time there are changes to the  or components that are connected to the storage array (such as hubs, switches, and ).

Read Test

The Read Test initiates a read command as it would be sent over an I/O data path. It compares data with a known, specific data pattern, checking for data integrity and  errors. If the read command is unsuccessful or the data compared is not correct, the RAID controller module is considered to be in error and is failed.

Write Test

A Write Test initiates a write command as it would be sent over an I/O data path (to the Diagnostics region on a specified physical disk). This Diagnostics region is then read and compared to a specific data pattern. If the write fails or the data compared is not correct, the RAID controller module is considered to be in error and is failed and placed offline. (Use the Recovery Guru to replace the RAID controller module.)

Data Loopback Test

Important: The Data Loopback Test does not run on RAID controller modules that have SCSI connections between the RAID controller modules and physical disks.

The Data Loopback Test is run only on RAID controller modules that have  connections between the RAID controller module and the physical disks. The test passes data through each RAID controller module's physical disk-side channel, minihub, out onto the loop and then back again. Enough data is transferred to determine error conditions on the channel. If the test fails on any channel, then this status is saved so that it can be returned if all other tests pass.

Notes:

• All test results are displayed in the Diagnostics dialog status area.
• Events are written to the  when Diagnostics is started, and when it is has completed testing. These events will help you to evaluate whether diagnostics testing was successful or failed, and the reason for the failure. To view the Event Log, use the Advanced >> Troubleshooting >> View Event Log in the .

Related Topics

Running RAID Controller Module Diagnostics

Recovering from Storage Array Problems

Managing a Storage Array