MSA1000 Disk Upgrade.

[Martin Stanjer]

Hello, Does this sound feasable:

We have an MSA1000 with two fully utilised 14 disk arrays in a W2K sever environment.

One array comprises 72GB disks configured with virtual disks that are themselves members of Virtual Replicator Pools (each pool's membership is exclusively from this array)

We want to increase capacity of the Virtual Replicator disks without adding members to the pools, but by swapping the 72GB disks for 146GB disks. (we have another use for the 72GB disks).

Our original plan was to backup everything, scrap the array and the VR pools and disks, recreate the array using the larger drives, recreate the VR pools and disks then restore everything.

But we now think we may be able to do the following:

Hot plug replace each 72GB drive in turn with a 146GB drive (allowing a rebuild after each one). Once all drives replaced we expect the ACU to see the extra unconfigured space.

Use the extension facility in the ACU to grow the existing virtual disks into the new space.

We then expect that VR will reflect the larger capacity by showing larger pools. Then we can use VR online volume growth to increase the size of the VR disks presented to the hosts.

Does this seem a bit too easy to be true?

We would of course back up everything before any config. changes, and make sure we are up to the latest firmware etc. first.
Thanks.

[Brian Plume_1 · Accepted solution]

This sounds like an excellent idea, but I'm afraid I don't think it's going to work.

Well, at least the last part doesn't sound like it'll work to me.

It is my understanding that you will not be able to change the size of a virtual replicator pool by merely changing the size on the MSA1000. I would say this whole thing would have worked had you NOT been using Virtual Replicator. See, then you could have swapped out the 72's for the 146's...one at a time like you mentioned, then the ACU would have seen the extra "unpartitioned space". Then you could have used diskpart.exe, a command line utility from windows, that would allow you to basically concatenate the two pieces together into one large disk.

Good luck with this, but i'm not sure you'll be successful with the virtual replicator pool part of it. My guess is your pools will become corrupt. Let me know what happens.

Brian

[Martin Stanjer]

Thanks Brian
I guessed that the VR part of the procedure might be a problem, so I tried to do this the more conventional way, by adding the new disks first in a new array, with the intention of creating new larger pools, and migrating the data.
Unfortunately, this has not been without problems: First I decided to update to the latest firmware on the controllers, EMU and switches. This went OK, as did the driver and agent update on the servers, but when I upgraded from Secure Path v4 to 4C, this caused blue screening on all servers when the fabric was re-connected. This was before the new drives were presented. After several re-starts, things were returned to normal, only to be faced with the same problem when I presented the new drives to the hosts. Agin several re-starts later, the new drives are seen in device manager (although some are listed as 'disk drive' rather than 'secure path disk').
Now when I try to add new pools in VR, some or all of the new drives are not listed as available drives by the wizard.
I have not yet tried unpresenting and re-presenting the new drives to the hosts, as I do not have the opportunity to re-start the servers at present.
Are there any known issues with Secure Path 4C, or is there anything I may be doing wrong here?
Thanks, Martin.

[Brian Plume_1]

Well, it depends....what service pack level are you at with your (i'm assuming) Windows 2000 servers?

There was a huge issue at one point with SecurePath and service pack 3 blue screening servers. I hated that service pack. hehehe Anyway, go to service pack 4 if you're not already. I haven't seen ANY issues with SecurePath 4.0c. NONE. It is a beautiful thing.

[Martin Stanjer]

Well thank you again Brian!
I am still on W2Ksp3, but I hadn't been concerned about it before because Secure Path 4C install notes say sp3 or 4 is OK. (In fact I was a little worried about going to sp4, because I wasn't certain that VR v3.0A would like it.)
I hadn't heard about this issue; It would be nice if the resolution is as simple as applying service pack 4. In fact Secure Path 4 has been working just fine, but I bet this is the trouble I am experiencing right now.
Did you experience the sp3 problems, or do you know under what conditions the blue screens occur, or where I might find this info?
Thanks,
Martin.

[Brian Plume_1]

I ran into the SP3 issue firsthand at two different client sites. Going to SP4 solved the issue.

SP3 is the devil's tools, my friend. Upgrade to SP4. It is so nice.

[Martin Stanjer]

That's very encouraging! Were your customers' symptoms similar to mine then? And more importantly, were any of them using VR (3.0A)?
None of the VR documentation that I can find mentions anything later than W2Ksp3. Do I assume that it was written before sp4 was out, or cut and pasted from earlier documents, or are we not supposed to use sp4 with VR 3A?.... This concern is the main reason that we have not installed sp4 already. (I am aware of the problem with Microsoft MS03-039 security patch. I guess this is rolled into sp4, but I would stop the VR services before installing the service pack)
Have you any experience of this?
Regards,
Martin.

[Brian Plume_1]

VR 3 is old news. VR 4 has been out for quite sometime now, so I think your assumption that SP4 was not available is correct. That is why it never made it into the release notes. I see no reason why you shouldn't move to Service Pack 4 with your current environment.

[Martin Stanjer]

Thanks Brian.
Actually, the release notes for the later versions don't mention sp4 either, so I think I will go for it on the assumption that this is just an ommision.
Very grateful for your opinion on this. I'll let you know how it goes. (Unfortunately, I can't schedule any downtime for about three weeks, so I'll be avoiding any online configuration in the meantime!)
Best regards.
Martin.

[Martin Stanjer]

Brian.
I've had a chance to try this.
I discovered we had to upgrade to VR 3.0B to allow us to install W2K sp4. (Minimum supported level) Also applied VR 3.0B sp1. Secure Path then seemed to behave itself. (No more blue screens when presenting new drives)
But we experienced problems with VR drive letters becoming mixed up (known problem with this service pack). Using the recommended restore drives utility caused major problems, because we had some new unmapped virtual drives that became mapped to existing drive letters, and previously mapped drives changed again to different wrong letters whilst also losing their labels. Now we had to un-present the new drives to make any VR changes without the VR management service crashing, and even now we have an incorrectly mapped drive letter that cannot be changed either with the GUI or CLI (latter gives â catastrophic failureâ message). I am rather cautious now, but intend to present new drives, and remove redundant drives one at a time. We have not exceeded 8 LUNs maximum per server (including system drives), so I donâ t know why we have had this problem. Incidentally, when adding and presenting new drives using SSP, although the new drives showed up in disk manager, they were not always all available for creating new VR pools: Had to write a signature on those disks affected which we have never had to do before. An