I'm facing a storage issue after replacing a failed drive in a RAID5 setup, and I could use some advice. We recently had a drive failure, which I replaced, but the new drive appeared as a different device name. After running a bus rescan, the drive showed up as /dev/sdj instead of /dev/sdd1. Now, my software RAID0 configuration (specifically /dev/md20) is broken because it references the missing /dev/sdd1. There's important data on the server that would take a significant amount of time to replace, so I'm hoping to resolve this without starting from scratch. Is there a way to tell the system that the new drive is actually /dev/sdd1? Will that allow it to recognize the drive in the RAID0 setup, or am I misunderstanding how this works?
2 Answers
It looks like you're dealing with a bit of a complex RAID setup. To fix this, first try checking the mdadm configuration. You might be able to use the mdadm --add command to manually add the new device to the md20 array. If mdadm doesn't recognize the drive properly, you could have to remove the failed device from the RAID configuration and then reassemble it. Make sure to backup any critical data if you can, just in case!
Be careful with RAID configurations, especially when drives fail and get replaced. It can get tricky! You can try updating the device in the array definition directly, but it might be easier to re-create the md20 array using the new device if it's giving you too much trouble. Just make sure to account for your data to avoid unexpected losses!
Thanks for the tips! I really want to avoid losing data. I’ll try to follow your suggestion to take a backup and then see if re-creating the array is a viable option.
Definitely back up what you can first! When you add the new drive to the array using mdadm, it should help the system recognize it, but keep an eye on how data is rebuilding. If you're unsure, running some commands to monitor the process is vital.