ProLiant Servers - Netservers

raid 5 expansion

 
Craig Shreve
New Member

raid 5 expansion

I am using the array config utility and I show 46304 MB unused space and the current array has 69455 in it already. When adding the unused space to I make the total size = to the used and unused added together?
2 REPLIES 2
Cameron Todd
Regular Advisor

Re: raid 5 expansion

I think that is correct, if you are not changing the RAID level. RAID 5 means one disk in the array will contain redundant data and this will not change if you add another disk.

However, if you were creating a new logical drive that is RAID 5 then the actual usable space would be lower than the total amount added, because of the redundant data area that was also created.
Stephen Gultig
Advisor

Re: raid 5 expansion

RAID 5 is striping over a minimum of 3 disks and if there is a hot fix disk in the array you will will have at least four disks. Assuming NO hot fix and three drives then the system will add the capacity of all three drives together and report that HALF of the total capacity is available.For example 3 x 40G = 120G but only 60G is available to use, the rest is for "backup" data in case one of the disks should fail.

So, to answer your question: Add the two together and double it. That is the total installed capacity but if you intend to keep RAID 5 you will only be able to use the sum of the used and unused.