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Converting a RAID5 to RAID 0+1

Tulip asked
We have a ML350 G3 with a Smart Array 642-Controller and 3 x 36GB HDD in a RAID 5.
My plan is to add 3 more disks and change the array to RAID 0+1.

Is this possible and if so what's the correct procedure for that ??
What stripe size is recommended for that. It's 16k at the moment.
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Distinguished Expert 2019
You only need 1 more disk to migrate from 3 disk RAID 5 to RAID 10. 3 more won't harm of course, you'll just have some extra space.

First upgrade to the latest drivers, firmware and Array Configuration Utility (ACU).  These will be found at http://h20000.www2.hp.com/bizsupport/TechSupport/DriverDownload.jsp?lang=en&cc=us&prodNameId=348783&taskId=135&prodTypeId=329290&prodSeriesId=348488&lang=en&cc=us

Then add extra disks physically.
Then open the ACU select the array and add the disk to it.
Then select the logical disk and migrate RAID level.
Ditto stripe size.

You'll see the options to migrate under common tasks when the disk(s) are fitted and the array or logical disk are selected, for help press the blue ? in top right corner. Note that you will not see the options in the wizard without the extra disk fitted. Some migrations on some smart array controllers are not possible without a battery backed write cache enabler.

Optimal stripe size depends on the application but 64K is normally good for most apps.

RAID level migration and stripe size migration take several hours but can be done online with everything running normally.


Thanks for your reply.

I already upgraded the drivers and ACU software.
But when I started it I was only offered to convert to RAID 0.
I thought I probably had to do it in two steps. First to 0 and after that to 0+1.

So, I only have to add the disks to my array and then the ACU will let me convert it
directly to 0+1 because of those extra disks, right ?!
Can I change the stripe size from 16k to 64k together with the RAID conversion
or should I do this in an extra step afterwards ?
Distinguished Expert 2019

Until a disk is physically added the ACU and added to the array it does not show the option to migrate to RAID 10, (or extend). It's quite annoying; I wish they would show the option but greyed out so you could click on it and it would tell you what was needed to enable the featiure.


yes, this would be less confusing.
Thanks for your help

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