Preserving User Data: Replacing a Failing RAID Controller with a Foreign Configuration

Preserving User Data: Replacing a Failing AOC-SAS2LP-H8iR RAID Controller (LSI MegaRAID SAS 9260-8i)

In this article, we will discuss the process of replacing a failing AOC-SAS2LP-H8iR RAID controller, specifically the LSI MegaRAID SAS 9260-8i. This guide will provide detailed steps and key concepts to help you preserve your data during the replacement process. We will cover the following topics:

1. Identifying a failing RAID controller

The first step in replacing a failing RAID controller is to identify the issue. Common signs of a failing RAID controller include:

• Disk errors or warnings in system logs
• RAID array degradation or rebuild failures
• Reduced performance or system instability
• Disk or array status alerts in the RAID management software

2. Choosing a compatible RAID controller

When selecting a new RAID controller, consider the following:

• Ensure the new controller is compatible with your server's form factor and backplane
• Check if the new controller supports the same RAID levels as the existing one
• Confirm the new controller is compatible with your operating system
• Consider the number of available ports and the maximum supported drive count

3. Preparing for the replacement

Before replacing the RAID controller, make sure to:

• Backup all critical data
• Document the current RAID configuration
• Ensure you have the necessary drivers and management software for the new controller

4. Replacing the RAID controller

To replace the failing RAID controller, follow these steps:

1. Shutdown the server and replace the controller
2. Connect the drives to the new controller in the same order as before
3. Power on the server and enter the RAID management software
4. Recreate the RAID array with the same settings as before
5. Allow the array to rebuild

5. Verifying the replacement

After the array has rebuilt, verify that all data is accessible and that the system is stable.

Code Block: Example RAID configuration in LSI MegaRAID management software

# Example RAID Configuration
[root@server ~]# megacli -LDInfo -Lall -a0

Adapter 0 -- Virtual Drive Information:
Virtual Disk: 0 (Target Id: 0)
Name                :
RAID Level          : Primary-1, Secondary-0, RAID Level Qualifier-0
Size                : 1.825 TB
Sector Size         : 512
Mirror Data         : 912.5 GB
State               : Optimal
Strip Size          : 64 KB
Number Of Drives    : 2
Span Depth          : 1
Default Cache Policy: WriteBack, ReadAdaptive, Direct, No Write Cache If Bad BBU
Current Cache Policy: WriteBack, ReadAdaptive, Direct, No Write Cache If Bad BBU
Access Policy       : Read/Write
Disk Cache Policy   : Disk's Default
Encryption Type     : None
Bad Blocks Exist: No
Is VD Cached: No
Cache Ratio         : 25:75

Replacing a failing RAID controller requires careful planning and execution to preserve user data. By following the steps outlined in this article, you can minimize the risk of data loss and ensure a smooth transition to a new controller. Remember to always backup your data, document your RAID configuration, and choose a compatible controller before proceeding with the replacement.

References

• LSI MegaRAID Management Software User Guide: https://docs.broadcom.com/doc/12354382

• LSI MegaRAID SAS 9260-8i Datasheet: https://www.broadcom.com/products/storage/raid-on-chip/megaraid-sas-9260-8i

• RAID Configuration Best Practices: https://searchstorage.techtarget.com/tip/RAID-configuration-best-practices-for-optimal-storage-performance