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RAID5 standby disk

Occasional Contributor

RAID5 standby disk



I wouldl iek to ask if it is possible to use a 1tb hard disk if my existing raid are 72gb?

Also may I ask if there is a available slot on the server can I plug a emtpy hard drive? What will happen if I plug it? 

Please adbvise. Thanks.



Mark Matthews
Respected Contributor

Re: RAID5 standby disk

The usual rule is that when any larger HDD is added to an array of smaller HDDs, the larger drive assumes the size of the smaller drives. So for example you'll only be able to use 72GB total of your 1TB drive.

With regards to a free slot, you should have a HDD blank in any unused slots in the server...

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Occasional Contributor

Re: RAID5 standby disk

Thank you for your reply. 


This helps us a lot.


Follow up question is if I plug empty disk in the server will this automatically be used upon failure of other drive? or do I have to configure it?


Please advise. Thanks.

Jimmy Vance

Re: RAID5 standby disk

As stated by another user, You can use a 1TB drive as a spare for your 73GB drives, the controller will treat it as a 72GB drive. You will need to run ACU (The Array Configuration Utility) to add the new disk as a spare.  One thing to note, make sure the 1TB drive is the same type, SAS or SATA as the existing drives as you cannot mix them in the same physical array

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Respected Contributor

Re: RAID5 standby disk

If you have unused drives installed in the server, they won't be automatically used to replace a failed drive.

You have to specifically configure a drive as a spare (or global spare) for that to happen. Otherwise it'll just sit there not doing anything until you want it to do something.