raid5 question

[michaewlewis]

I'm working on a plan for a new nas server and have six hard drives right now that I can set up in a raid 5 array. Ultimately I want to have 10 hard drives in the array.
Does anyone know if I can add the four extra drives to the array later without having to completely rebuild the array? Or would I have to copy all of my files to another hard drive and delete the array, add the four other drives and rebuild?
I think that's what I'll have to do, but wanted someone else's opinion.

[michaewlewis]

If anyone is interested, in order to be able to add capacity or make any changes to a raid volume, the raid controller must be capable of RAID level migration. Some controllers will even let you make the changes on a live system.
Intel, Promise, and 3ware controllers have this capability. I'm not sure about any others.

[patio]

Changing live ? ?
That's pretty impressive i wasn't aware this could be done.
Course Marge Simpson is probably more fluent in RAID than i am...
 

[michaewlewis]

I didn't know it could be done either, neither could my supplier. But then I got wise and looked at one of my intel raid controller boxes and it said in bold letters that all intel controllers could do it. Sooo I did all my research to see if it could be done, only to find the answer on a box on my desk.

[patio]

Which RAID modes can this be done with or all of them ? ?

[Spoiler]

Controllers out today let you expand the array by adding drives and than going into the configuration software and telling to use the new drives. Its dynamic and just refigures the strip set to not only use the new drives but it also changes the old drives to the new strip set. It’s all done automatically.

Its pretty cool stuff....

[michaewlewis]

Which RAID modes can this be done with or all of them ? ?

I think it can be done with all arrays...

[Spoiler]

http://www.intel.com/design/servers/raid/SRCSASBB8I/index.htm

Fault tolerant features 
Online capacity expansion