I have a PowerEdge R520 with 6, 600 GB SAS drives in RAID5 running as VM host for critical SP and ERP servers. Last week the server crashed. I went to the data center and found out that one of the six drives had a blinking orange light and the server was in BIOS mode unable to load the OS. Upon restarting, "Foreign Configurationmessagege popped up. I impoted the Foregon config and was able to Boot to OS. The server stayed up in this state for few hours before crashed again. I ordered a new drive and took it to the data center today. The server was again in the crashed stage. I inserted the new drive by replacing the old one and got the BIOS message about the "foreign configuration. Pressed C and another messages showed up in BIOS about the controller configuration being changed and it is an irreversible process. I left everything at that point to get some advice before moving forward. Here are two questions I have.
1) In RAID 5, single disk failure should not take the server down. Why is my server keep crashing? I did not find anything related to the controller when I was able to boot to the OS earlier this week.
2) In which order should I swap the drive. Should lI put the old bad drive back in the system? Import the Foreign config and boot to the OS and do a hot swap?
3) If i start the server by inserting the new drive then what should I do with the Foreign config message and the message about "you are about to change the configuration on the controller". Is this the safest route.
The whole idea behind this long message is to avoid any DATA LOSS. I have not pressed any wrong keys at this point, therefore all of my current data is intact and I can boot to the OS using the old disk which will crash in few hours. I certainly don't want to lose any data and config at this point.
Thanks