HPE Storage Users Group

First of all I would like to apologize if this has been discussed in this forum before. I am new to the forum (still learning its nuances) and fairly new to 3PAR.
Our 3PAR 8200 has been in service for less than a year and in the last two months we have had 4 FC drives fail so it was suggested to us that we should change the RAID level from 5 to 6. I have never done this before and in my Googling for answers I could not come up with anything specific in my personal knowledgebase that lead me to a specific answer. There was talk of tuning, etc. but not specific commands or how to do so in SSMC. In doing the RAID change is it better to create a new CPG with the new name, FC_r6 then move the VVs to it , or to rename the CPG to FC_r6 from FC_r5 after changing the RAID level?

Simplest method would be to edit the properties of the CPG from raid 5 to raid 6 with setcpg at the cli or within the GUI (CPG, actions, edit). Then either do a tunesys -cpg <cpgname> at the cli or a tune (system, actions, tune) from the GUI which will change the raid layout of existing data to match.

CLI Guide here: http://h20564.www2.hpe.com/hpsc/doc/public/display?docId=c04204279

It's also possible to create a new CPG and tune each volume individually assuming you have dynamic optimization, but it's potentially a lot of work for very little if any gain.

The SSMC GUI will not allow me to change RAID type. I can only change SET SIZE and AVAILABILITY.

If you do change the RAID type of a CPG via setcpg remember that logical devices already created do not get converted to the new RAID6 template, only new ones from that point on will be RAID6 .. so if you have a thin volume that is only half full, and then fill it .. half the logical disks making up that volume could still be RAID5.
Which is why you would need to manually kick off some tunevv's to get the LDs migrated over to the new format.
Changing an existing CPG is messy ... better to create a new CPG and tunevv volumes over.
If you have no license go hassle your HPE sales rep and see if they will get you a "trial" license or something

After changing set size and/or RAID type on a CPG you can also just trigger tunesys which doesn't require a license. Just keep an eye on the tasks to make sure some of them don't fail. If they do you might need to manually tune some LDs. (showld -d will show every LD, their RAID type and set size).

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The views and opinions expressed are my own and do not necessarily reflect those of my current or previous employers.

By the way, when the CPG decides to create a new LD instead of growing an existing one ? How much an LD can grow ? I think the CPG tries to have very little difference in size between LD's ?

I think showld -d will show that as well. Alternativly showld -s. If my memory serves me right it it will rotate to a new LD after growing to 256GB net size.

_________________
The views and opinions expressed are my own and do not necessarily reflect those of my current or previous employers.

Well, I finally got it to work. I had to do a showcpg -sdg to get all the parameters for the CPG then do a setcpg with all of those parameters with the changes needed to go from RAID5 to 6 -
so the command was setcpg -t r6 -ssz 8 -ha mag -p -devtype FC
The tunesys is running now.

Thanks for the help!