Adding space to a RAID without destroying data

[irbk]

A question was posed to me today that I couldn't answer. Say you have a 3 physical disk RAID 5. Space is getting tight on that RAID 5 and you would like to add more space to it by adding another physical disk. Can you add another disk without having to reconfigure (thus loosing all the data on) the RAID? I know that if a spindle dies in a RAID, you can replace the dead spindle and bring the RAID back up with no lost of data, but I don't know about increasing the size of a RAID without data loss.

Thanks in advance.

 

[irbk]

On some more digging, I think I've found that the answer to my question is "It depends on if your RAID controller will allow it or not".

 

[goombawaho]

That would be correct. The better (think server grade) RAID controllers will almost always allow that. It would be very limiting for that NOT to be a feature.

Your el-cheapo ones for home computers aren't nearly as likely to allow it.

Be very careful when you do this as you can destroy arrays and/or logical drives if you don't know what you're doing.