Take the 2-minute tour ×
Server Fault is a question and answer site for system and network administrators. It's 100% free, no registration required.

So I have just set up a 3x2TB software raid-5 array on my Ubuntu Desktop 10.04. I replaced three existing non-raid disks, but left the boot disk non-raid (the way it has always been).

Q: If the boot disk dies, is the array lost, or can I boot from a LiveCD and still access the array? I have a 10.04 server machine right next to the machine with the array in. Could that take over looking after the array if the bootdisk dies?

To be clear: I asked this over at askubuntu, to no avail. I want to know what to do in the eventuality that my boot disk goes down. Thanks.

share|improve this question

migrated from askubuntu.com Jun 16 '11 at 15:56

This question came from our site for Ubuntu users and developers.

    
You're backing up anyway, right? RAID is not a backup... –  RobM Jun 16 '11 at 19:35
    
Actually, yes. I have offsite backup in the form of an external HDD backing up everything that cannot be replaced. –  Frank_Zafka Jun 16 '11 at 19:54

2 Answers 2

up vote 3 down vote accepted

The answer to your question is NO. The raid metadata is stored on the disks so you can take them to any computer running any modern Linux distribution and use mdadm to detect and start the raid array. I know that the Ubuntu Live CD doesn't include LVM but I'm not sure if it has mdadm or not. That's not really a problem it just means that you may have to run sudo apt-get update and sudo apt-get install mdadm after booting up on the Live CD. And then start the array up and mount it manually.

Other live cd's like System Rescue CD include and automatically look for LVM and mdadm (software raid) volumes. So depending on what you're looking for it may be a better option for system recovery.

share|improve this answer
    
The Ubuntu Alternative LiveCD does include LVM and may also support your RAID array. Give it a try and see what happens. –  KayakJim Jun 16 '11 at 18:42
    
Okay. That all makes me feel a lot better. I was concerned about having to deal with it when it was failing. I will set up a virtual machine and test out rebuilds etc. Thanks. –  Frank_Zafka Jun 16 '11 at 19:55

I would buy an hardware controller, HP makes some nice one's HP p200, p400 or p410

Don't know much about software raid, but if you take backup of the Host OS you should restore it and the raid is working again.

share|improve this answer
    
Good advice. Doesn't really answer my question. I already have the 3tb raid system in place and don't have resources to purchase new equipment. I have to deal with what I got. :) –  Frank_Zafka Jun 16 '11 at 16:22

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.