Smart Array 6i Raid 5 to Raid 10 migration idea

[jordanl17]

I've currently got 4 36gb drives in a raid 5 array. The system has 2 open drive bays.
Do you think I could put 2 147gb drives in the remaining 2 drive slots, build a raid 1 container, and then migrate my raid 5 to that raid 1 container.
AND THEN put 2 more 147gb drives in place of the the old raid 5 container, build another raid 1, and then I can convert the raid 1 to raid 1+0.
This is for a Terminal Server, and I was reading that raid 10 is much better for Terminal Server.
Thoughts?

[jordanl17]

Also, just noticed, I do NOT have a battery. I probably need to buy one. right?

[TTr]

A 4x36GB raid5 array can not have more than 100GB of data in it. It might be quicker to backup the data and recreate the 4x146GB raid10 array from scratch.

If it is i/o performance you are after, buying the battery and setting up write cache will help a lot.

Also you can replace the 36GB with the 146GB drives one-at-a-time and allow each drive to rebuild befor replacing the next one.

See page 30 http://bizsupport1.austin.hp.com/bc/docs/support/SupportManual/c00217854/c00217854.pdf

[jordanl17]

so a good alternate plan would be to use Clonezilla to do a disk image dump to a remote location. build a brand new fresh raid 10 array, and then use Clonezilla to restore.. right?

[TTr]

I am also a little sceptic on the raid10 vs. raid5 topic. It is believed that raid10 outperforms raid5. That was generally true in the early years of the raid technology. In the recent years it is not always true. It depends on many factors, the controller processing power, the i/o channels, the disks, the disk spread on the i/o channels, the i/o pattern (small or large reads) etc. If you have the option (it looks like you don't) do some testing with raid5 (now) and raid10 later.

[gregersenj]

Should be possible to go directly from RAID 5 to RAID 1+0 in your case.

You could put in 2 more 36 GB drives, and get a 6 drive RAID 1+0

You could replace 2 of the drives 147 GB ( one at the time), and migrate to a RAID 1
Then replace the last 2 disks (one at the time) Then migrate to RAID 1+0
And extend the logical drive or create an additional drive.

Or you could replace all 4 drives (one at the time) and migrate to RAID 1+0, then extend the logical drive or create another logical drive.

Just have to decide on what is your goal.

You just need to check if you have the need for BBWC to do the Raid Level migration.
I'm not 100% sure. But i don't think BBWC was needed on the old Parallel SCSI Smart Controllers.

Perfomance wise, I don't know for sure.
But not doubt's on the write penalty on RAID 5.

BR
/jag

[gregersenj]

Q&A on the 6i:
http://h18000.www1.hp.com/products/servers/proliantstorage/arraycontrollers/smartarray6i/questionsanswers.html

User guide:
http://bizsupport1.austin.hp.com/bc/docs/support/SupportManual/c00217854/c00217854.pdf

Quick Specs:
http://h18000.www1.hp.com/products/quickspecs/12067_na/12067_na.HTML

Unlike the P end E Smart Arrays, I don't find anything saying that BBWC is needed for RAID level migration.

Also read the ACU user guide, on how to migrate the RAID level.

Just remember You must have the free capacity appropriate to do the migration.

ACU user guide:
http://docs.hp.com/en/9320/acu.pdf

BR
/jag