Re: Mirroring on i5/OS -- MIDRANGE-L

Wayne,

Both you and Pete were correct on this (I think). I started out with the two drives, unprotected, and wanted to mirror them to the two non-configured drives I had. When I couldn't do that with iNav, I just figured it was a "feature" in iNav. I think it was, instead, an issue with one of the two drives being the load source and needing to be individually mirrored first. I was trying to mirror BOTH in iNav. What I ended up doing was to mirror the drives in DST. However, even though I *thought* was was mirroring the pair, even in DST I ended up with my two configured but unprotected disks being mirrored to each other, going from 254GB to 127GB in capacity. I followed what I thought was the correct steps, confirmed by Lukas, to take the option to select the two configured, unprotected drives and start mirroring and it would "automagically" find the non-configured pair and use them to mirror. Not so. The two I selected were mirrored to each other as the load source.

When that was done I saw what had really happened in iNav. So I took the option in iNav to add disks to the mirror protected "disk pool" and it would only allow me to add the unconfigured *pair* to the pool, which makes sense. When I took that option, I eventually ended up with two mirrored pairs in the pool.

So, you were correct, I just needed to first mirror the load source and THEN use the unconfigured pair to add to that mirrored pool. I probably just misunderstood your instructions. Pete was correct in that it could be done from DST pretty clearly (it WAS a bit clearer in DST).

So again, thanks. 4 hours of machine time got the job done and all is well and protected.

Pete

Wayne McAlpine wrote:

Your two disks are each more than half full, with one being the load source, so they can't be mirrored. When you add two more disks, you should be able to have two mirrored pairs.

Pete Helgren wrote:

I am still not understanding I guess.

I have (had) two disks in the pool that had no mirrored protection. I had two other non-configured units that I could use for mirroring (I assumed). What I need are the steps for creating the mirror. When I first went into iNav, and went to "Disk Units" under Hardware, there was one pool: "Disk Pool 1". I had two disks in that pool. Taking the option for Mirroring --> Start Mirroring I got a message saying "There are no eligible disk pools for the action "Start Mirroring" "
So the question is: With two disks allocated to Disk Pool 1 and given that there aren't any disk pools eligible for mirroring, how do I create a disk pool that IS eligible?
The bummer is, while I was waiting for a post back, I added the two non-configured units to the asp and now I can't remove them. I think I'll go to DST and straighten this out. The iNav route isn't getting me there.

Pete

Wayne McAlpine wrote:

If you add a pair of disks to the mirrored storage pool, they will automatically be mirrored. It has its own algorithms to figure out the most effective mirroring configuration, i.e., bus level, controller level, or disk level.

Pete Helgren wrote:

What is throwing me is whether I need to add the non-configured disks to the pool first and then implement the mirroring or start mirroring and indicate that I want the non-configured units to be the mirrors. Seems like a chicken or egg thing: If I add the non-configured units to the asp, they won't be available to be the mirrored pair (I think).

With raid 5 you just add the units to the asp and tell it to start RAID protection and it all seems to work. With mirroring, I not sure how to tell the configuration tool that the non-configured units are the ones I want to be mirrors. Even in iSeries Navigator, it isn't clear. I guess I'll try adding the non-configured units and then see if I can start mirroring after they are added to the pool.

Otherwise, I'll try Pete's approach and see what my options are at IPL time.

Thanks

Pete

Wayne McAlpine wrote:

I believe you can also do it from iseries Navigator. Click on Disks-->Disk Pools-->right click on the pool to mirror and take the option to start mirroring.

Pete Massiello wrote:

Pete,

Try booting up in Manual mode and go into DST and WORK WITH DISK
Configuration. From there you will see what you need.

Pete

Pete Massiello
iTech Solutions
http://www.itechsol.com

-----Original Message-----
From: midrange-l-bounces@xxxxxxxxxxxx
[mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Pete Helgren
Sent: Wednesday, November 12, 2008 1:52 PM
To: Midrange Systems Technical Discussion
Subject: Mirroring on i5/OS

I thought this would be easy but I must be a little slow this week...

I have my JS12 configured with 4 drives allocated to i5/OS (More accurately I have VIOS allocating 4 drives to the JS12 from the 6 available in the BCS). Two of which I have configured as part of ASP1. All is well. However, I'd like to get some protection on these drives and my understanding was that mirroring is my only option. So, how to I achieve that ? Disk hardware status shows this:

Serial Resource Hardware ASP Unit Number Type Model Name Status 1 1 YWEB5KZWKZRX 6B22 050 DD004 Operational
1 2 Y9EJAR7L8YMZ 6B22 050 DD003 Operational
Y384SV9UX3VE 6B22 050 DD001 Operational
YJA2X8PBPAUR 6B22 050 DD002 Operational

So, as far as I understand it, the two drives that are unallocated could be used to mirror the other drives but I don't see any option in SST to use these drives in a mirrored arrangement. Work with Device Parity protection show the following menu:

1. Display disk configuration 2. Include unit in device parity protection 3. Start device parity protection - RAID 5 4. Start device parity protection - RAID 6 5. Start device parity protection - RAID 5 with hot spare
6. Start device parity protection - RAID 6 with hot spare
7. Select parity optimization No mention of mirroring.....

So, how do I mirror these things? I get plenty of hits on mirroring "Concepts" in the infocenter but precious little about implementation. Running IBM i 6.1 on a JS12.

Pete