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WolfFlag for United Kingdom of Great Britain and Northern Ireland

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How do I add an additional HDD to a Raid 5 setup after disk failure?

I have an Hp Proliant DL380 G5 server which had a failed HDD, it had the Red/Orange light on it.  Unfortunatly while waiting for a replacement drive to be delivered the server rebooted itself and all the lights on the faulty HDD went out.

The new HDD has been delivered and after swopping the old for new the lights still remain out on the new HDD, but the other 3 seem to be fine.  I've checked on HP Systems Insight Manager and its now showing that three of the HDD are in Raid 5, but the 4th drive is only a "SPARE".

Is there a way of adding the 4th drive into the Raid?

Thanks
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TheCapedPlodder
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Were all four disks in the RAID array before or we three in the array with the fourth as hot spare?
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ASKER

All four disks were in the array before the disk failed
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Does the Raid Manager show a Degraded RAID?  Do you have the same amount of Space on the Array? If not your setup was originally setup with a HOTSPARE which automatically replaced the degraded drive and the new drive has become the hotspare.

If the above is true you wanting to add this drive into the array - you will get more capacity but lose the resilience you have just experienced.
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How do I check if it was part of the array before or not?  I'm not very knowledgable on arrays
Ignoring my post above because you have just answered it.

Has the total drive size decreased?
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I can't be 100% sure that it was part of teh array before hand, as the server was built about 6 months ago
Is there a way of checking?
You should be able to calculate it from the hard drives you have in the server.

Simplistically:

RAID5 size = <Number of Drive in the Array > x <hard drive space>- 1 x <hard drive space>

so if you have 72Gig HDs

with 3 Drives and 1 HS = 144Gig Capacity in Total (3 x 72 - 72) + HS = 4 drives
with 4 Drive and no HS = 216Gig Capacity in Total (4 x 72- 72) = 4 drives.





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ASKER

I have 4 146Gb drives in the server, and Computer Management it is showing as:
c: Capacity 19.53Gb
D: Capacity 253.87Gb
Its definatly setup as a single logica drive though
Not quite sure how i work it out from that?
In that case you had a RAID 5 array with three disks and fourth disk dedicated as hot spare.

Plod
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Wadski
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Thanks very much for your help :)