Expand Capacity with RAID 5

Ivannovish

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Feb 25, 2014
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I am using a motherboard with Z68 chipset with oROM (Intel RST v. 10.0.6.0.1002). I created a RAID 5 with 3x 466GB HDDs [WD5000BPKT] 5 or 6 years ago, when the system was new. This gave a usable volume of about 932GB. I recently added one 932GB disk [WD10JPLX], and expanded the volume to include the new drive (about 1398GB or 3x 466GB). Then one at a time, I swapped out the original 3 drives, rebuilding the "degraded" array each time, until I ended up with a RAID 5 on 4x 932GB HHDs [WD10JPLX]. After everything was done and happy, I ended up with only 1/2 the total usable storage in the volume that I expect (~1.4TB instead of ~2.8TB). Even though it recognizes that I have 4x 932GB, it behaves as though I have 4x 466GB (original drive size). How do I expand the capacity to use the whole of each HDD? I STRONGLY prefer NOT to wipe and rebuild.

BTW: This is not my boot drive, this is my data drive, using Win7-64, I have all my user data and user libraries and such pointed to the array, in order to keep the boot drive available for installed programs. Boot drive is 1TB Samsung 850 Pro SSD.


Thank you for the help!!
 
Solution


That is generally the recommended way ahead.

I have a 4x3TB RAID 5, about to change it (1 drive at a time) to 4 x 4TB RAID 5. Linux based NAS.
If it does not increase automatically, I'll simply copy all the data off to the backup 8TB drive, rebuild the array with hte larger drives, and copy the data back over.

(you should really have a backup anyway...:) )
Most raid controllers won't rebuild with the higher capacity. Even though you put a larger drive in, it only used the original 466GB when it rebuilt.

The way around this is to back it up, blow away the raid and rebuild it with the larger disks - utilizing the full size of the disks.
 

USAFRet

Titan
Moderator


That is generally the recommended way ahead.

I have a 4x3TB RAID 5, about to change it (1 drive at a time) to 4 x 4TB RAID 5. Linux based NAS.
If it does not increase automatically, I'll simply copy all the data off to the backup 8TB drive, rebuild the array with hte larger drives, and copy the data back over.

(you should really have a backup anyway...:) )
 
Solution