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Mirroring RAID 0 disk that has OS installed

Occasional Contributor

Mirroring RAID 0 disk that has OS installed


I have a DL380 G4 with a 6i Controller. The servers has 5 x 146 GB drives RAID 5 and 1 x 36 GB 15K drive RAID 0. The 36 GB 15K drive contains my OS. I want to delete the RAID 5 array, remove one 146 GB drive, RAID 5 the remaining 4 x 146 GB drives, install a 36 GB 10K drive, and then mirror (RAID 0+1) the 36 GB 15K drive containing the OS to the 36 GB 10K drive without losing the OS. I've reviewed the HP Array Configuration Utility User Guide, but it seems pretty generic on this issue. Can someone provide me more detailed instructions? Also, any issue with mirroring a 10K drive with a 15K drive other than the 15K drive will run at 10K?

Honored Contributor

Re: Mirroring RAID 0 disk that has OS installed

First thing first:
RAID 0 means stripping across multiple disks, while mirroring is described as RAID 1
(I always found this page quite useful re RAID level terminology:

You could add new drive to the existing one and then mirror them without loosing any data (thanks to a neat feature called Online RAID Level Migration).

Re mixing different speeds: it's not the best practice but you could live with that. In fact both drives will still spin with their nominal speed, but the faster drive will simply wait for the slower one to finish write operation.
Don't panic! [THGTTG]
Prashant (I am Back)
Honored Contributor

Re: Mirroring RAID 0 disk that has OS installed


Refer to think link all about the controller and RAID tech from HP
Go Technical session in this that will help you more.

Where you can mix the dive of different RPM but not recomended.

Prashant S.
Nothing is impossible
kris rombauts
Honored Contributor

Re: Mirroring RAID 0 disk that has OS installed


what you are planning is perfectly possible
, just need a backup from the raid5 data and restore it once the new raid5 array with 4 disks has been created.

The migration of the one disk raid0 to two disk raid1 is possible and can even be done while the server is online.

- First add the 36 GByte disk to the raid0 array, called 'SCSI array A' by doing a "expand array" and adding your new 36 Gbyte disk and save the config.

- when the array "expand" is finished then "migrate" the logical drive in array A from raid 0 into raid0/1 by right clicking the logical drive in the ACY utility and selecting raid 0/1 and save the config change.

Once finished, your boot disk is now protected if one of the disks ever fails.

It's best to set the of the expand priority to high in the controller settings to speed up the process, if not it can take some time.