RAID 5 Disk Upgrade

[itboff]

Hi,

I am upgrading the disks in my RAID 5 array from 70Gb to 144Gb ones.

Replace each drive individually eventually moving to all three 144 drives? (Will the array detect its new size).

Or am I better of backing up all the data removing the drives installing the new ones and restoring the data and the shares.

Thanks

[itboff]

Forgot to mention I have an ML350 with a Smart Array 641 Controller.

[mavrick]

Better you backup all your data and create the new RAID5 with large capacity.Otherwise you have to compromise your disk space

[Victor Semaska_3]

As mavrick mentioned you should back up your data and create a new RAID-5 set from scratch.

If you replaced each disk individually only 70 GBs of each of the new 144 GB disks will be used. The rest will remain unused.

Vic

[Amar_Joshi]

Hi Itboff,

I am interested in this topic since you posted but I was waiting for some GURU to answer this. the previous 2 answers are quite justifiable because of the standard practices.

I am somehow interested in your solution of replacing the disks one-by-one with higher capacity, unfortunately no-one is able to answer whether it's possible or not? I know sometimes backup a big amount of data and restoring is a tedious task specially in live environment. Can you (or someone) tell me whether it's possible to replace the small size disk with bigger size disk or not? if YES, then you have the option (though not highly recommended) to replace the disks one by one and at last have it replaced all.

waiting for your reply...

[itboff]

That was the plan, not looing good though. I was wondering if it was possible to expand the array once all the drives had been installed, then I would be able to increase the size of the share on the server (expand the disk windows 2003 server).
We use REV drives and Veritas to backup the system so I think it will take about 5 hours maybe more to back everything up and the same to restore it.

It just means that we will need some down time in order to complete (500 user areas on the server :<)

[Victor Semaska_3]

Hi Amardeep,

The answer is no, you can't increase the size of a RAID-5 set by replacing the disks one at a time.

Vic

[Arakattack_1 · Accepted solution]

People said online raid expansion can be done in windows server. Linux user have to do it with creating LVM to create new partition and map unused space.

[Puneet Arora]

Hi, I am sure we can replace the 3x70GB disks by 144GB disks one by one, still resulting in a RAID 5 but of the original size.
To increase the size of the RAID including all the space provided by 144 GB harddrives, we would need to extend the array, once rebuild is finished, and we can add the additional space to the same array.
So it would not be one step process but 2 steps
1) replace all the hard drives one by one
2) Extend the RAID 5 to include all the additional space.

[itboff]

Is that definatly possible? If so it would save me a huge amount of a lot of time ... (down time).

Thanks for the tip, I hoped that I could increase the array in this way ... think i will give it a go .. if it dosnt work I havent lost anything I can always create a new array once eveything is backed up (i.e. reformat and start again).

I have the disks now and will start replacing the drives tomorrow :)


Thanks

Chris