MSA1500 - Active/Active Yet?

[SAKET_5]

Hi Guys,

Just after confirmation - my understanding is that MSA1500 with the current FW V.4.98 does not support Active/Active controller configuration. Could someone please confirm this for me. I obviously do not get to play much with the MSA1000/1500s :(

Anyone knows when V5.x of the FW is expected and will it definitely bring the controllers to behave "Active/Active" for different LUNs?

Regards,
Saket.

[Uwe Zessin]

The next date for MSA Active/Active failover I got told was december 2005, but if I remember it was only for the MSA1500. It's my understanding that you can have different logical disks owned by different controllers, so it works somewhat similar to the EVA XL.

[Luk Vandenbussche]

Hi,

MSA1500 is not supported in active/active mode yet

see

http://h18000.www1.hp.com/products/quickspecs/11945_div/11945_div.pdf

[John Kufrovich]

Uwe is correct, December time frame. We have a few more kinks to work out. The 1500 will be initially supported. The 1000 in a few months after. Expect v6.xx FW.

[SAKET_5]

Thanks guys,

any particular reason as to why HP-UX is only supported in single controller configuration? Also, the limitation on the number of cluster nodes(Windows) that can connect to the MSA1000/1500cs - is it just a test/certification issue or one that is strictly technical in nature?

[Vincent Fleming]

The reason MSA is only single connect on HP-UX is because it's not active/active; I believe that the SecurePath (aka AutoPath) software was not modified to handle the MSA failover as-is is because: 1. VA7xxx exists, and 2. active/active has been scheduled to be here soon.

As for the Windows clustering, I'm not sure, but I'm sure it's a combination of both techical reasons, testing capacity, and the idea that if you have more than 16 nodes, you should be in an EVA instead of an MSA anyway - ie: the target market is too small to bother with the testing.

Regards,

Vince

[Basil Vizgin]

I hope, that MSA active/active will be different from VA realisation. In VA array all load via second controller goes to disk through first controller...

[Vincent Fleming]

Basil,

Other than cache-centric arrays, they all work that way... even from our competitors.

Regards,

Vince

[Uwe Zessin]

It depends on the type of VA:
true for the VA71x0, which has only one redundancy group (RG1).

The VA74x0 has two RGs. In a two-controller configuration, each controller is responsible for one RG - so you can divide your load through both controller's performance paths, unless you only make use of one LUN (leaving the other RG empty).

[Basil Vizgin]

Vincent, but why cannot we split cache for controller part and mirror controller part?
Yes, we loose half of the cache capacity, but wins in controller performance, which is weak (30K I/O's) in MSA.
Also can you point me to competitors models, which work in such "two pathes one controller" way, as you say? I didn't find such info nor in IBM, nor in EMC or even Adaptec documentation...
Thank you in advance!

[Vincent Fleming]

In all (midrange) arrays, only one controller actually does writes to a set of RAID disks.

They do this because of the overhead that would be required to coordinate activities between the controllers would be so much that it is not worth doing - there would be no benefit to the scheme. Maintaining cache coherency and locking are the most heavyweight activities.

So, what's typically done is I/O's are forwarded to the "owner" controller, thereby removing the need for cache coherency and locking.

[Basil Vizgin]

MSA is entry-level array. All midrange EVAs, as I understand, can do cache mirroring and both controllers can work simultaneously (LUN balancing).

[John Kufrovich]

The MSA will support both methods, Automatic and Manual(preferred_path).

In the Automatic mode, the first controller will proxy over cmds to the second controller. If that LUN on the second controller gets busy, the FW will automatically move that LUN under the first controller.

In Manual mode, you will be able to select which controllers get which LUNs.

[Basil Vizgin]

Thank you, John!

And what about MSA1000? When planned active/active fw for MSA1000?

[Jefferson Humber]

Basil,

I thought I read on here a little while ago that was still coming to the MSA1000, but maybe not until v.6 for the F/W. Might of dreamt it, but I'm sure I sure it somewhere here.

Jeff

[Jefferson Humber]

Basil,

I thought I read on here a little while ago that it was still coming to the MSA1000, but maybe not until v.6 for the F/W. Might of dreamt it, but I'm sure I sure it somewhere here.

Jeff

[DanDelcroix]

Any update on the release for the active/active FW for the MSA1000 and/or MSA1500 ?
Thanks and regards,
Vermaanen

[Fabian_Nowee]

Jep, we're testing with 5.02 but we see no active/active components yet.

[Basil Vizgin]

Found this new documents:
HP MPIO Full-Featured DSM for Windows for MSA Disk Arrays 1.00.00 release notes
http://search.hp.com/redirect.html?type=REG&qt=mpio&url=http%3A//h20000.www2.hp.com/bc/docs/support/SupportManual/c00586805/c00586805.pdf&pos=1
and HP MPIO Full-Featured DSM for Windows for MSA Disk Arrays 1.00.00 installation and reference guide:
http://search.hp.com/redirect.html?type=REG&qt=mpio&url=http%3A//h20000.www2.hp.com/bc/docs/support/SupportManual/c00586802/c00586802.pdf&pos=9

From release notes:
-----
The HP MPIO MSA DSM supports the following disk array:
â ¢ MSA1500 with firmware version 6.x.
Coexistence with Secure Path on same server* Yes
Coexistence with HP MPIO basic failover for EVA arrays on same server* Yes
Coexistence with HP MPIO basic failover for MSA arrays on same server* No
---
Release day is coming?:)

[Basil Vizgin]

John, any news yet?

[John Kufrovich]

We can almost see the light.

Training sessions have already started. White papers have been generated.

[Mark Bridgett]

Another 4 weeks and still no firmware? I also hear that the active/active will not be supported on XP as External Storage for perhaps a further 6 months!

[Basil Vizgin]

Officially announced for homogeneous HP-UX/Windows/Linux/OpenVMS/Tru64 environment.

[Jefferson Humber]

Basil,

Do you have a link for this news ?

J

[Basil Vizgin]

Jefferson, look into quickspec:)
Official start May 8.