MSA-1000 or VA?

[Derek_31]

I'm using several MSA-1000 for small sets of servers (less than 10) and have been happy with them. However, I do miss the hardware snapshot capability and limited LUN expansion options (can't delete a LUN, expanding the first lun forces all of the others to move, etc.).

I now have a set of 40 Windows servers that I need to connect to a SAN. Total data storage is about 200 to 300 GB, and it will have a fairly light user load (less than 200 average office users).

My first inclination was to get an MSA-1000 with 28 72GB disks and make various RAID-5 and RAID-1 sets for my applications (mainly SQL, Exchange, and file sharing).

Because of the 16 host limit of the MSA-1000, I might need to expand to 2 MSA-1000s.

I've never used the VA line of arrays and so I don't know how easy/hard they are to manage and if they would be better for my environement.

Anyone have an opinion?

[Uwe Zessin · Accepted solution]

I beleive the VA7000 series storage arrays are to go end-of-life next time.

I suggest you take a look at the EVA-3000 instead. It has become more price-attractive, I think (I don't have any numbers, I am not a sales person and I work in Germany).

The EVA can create virtual disks ranging from 1 GByte to 2 TByte in 1 GByte steps. You can expand the size of a virtual disk and delete it at any time and in any order. You can put additional disks in a disk group and you can even remove disks from a group provided that there is enough free space.

The array has two controllers with two ports, each. You can only do I/O to a certain virtual disk through a single controller, but you can use both ports of that controller. However, you can split your virtual disks over both controllers, because this is an active/active configuration.

You can take snapshots. As far as I know the VA7000 series always reserves 100% space for a snapshot. The EVA can do that, too, but it can also do 'demand allocated'. Finally, you can create a SnapClone - that is a new virtual disks which starts like a snapshot, but the array automatically makes a full copy of the data over time. In the end you have a completely independed virtual disk, which can even live in a different disk group.

Management of the EVA is done through a Web browser. It connects to a dedicated server, the Storage Management Appliance (SMA), which is _required_ to manage the EVA. A command line oriented scripting utility is available, too (it sends commands through the SMA).

When you need snapshots you buy Business Copy EVA (BC EVA). It includes the snapshot license for the EVA and a framework for taking snapshots that runs on the SMA. It can assist by providing automatic undos, for example.

Here is a link to the EVA-3000:

http://h18000.www1.hp.com/products/storageworks/eva3000/index.html

Please, do not attempt to find out all necessary part numbers on your own! It is easy to forget an important piece.

[Andy McCreath]

I'm going to side with Uwe on this one the EVA-3000 is the one for you.
Don't go crazy on the unit, buy just what you need and make sure you get at least a Priority Plus maintenance agreement on it!

I would also suggest if you have 40 host servers and these are planned to be dual pathed you opt for a Brocade 12000 Silkworm core switch. This will give you a 2 x 64 port configuration with ZERO downtime.

It looks like you have already grown out of the MSA market, time to trade up.

Godd Luck,

[Derek_31]

Thanks for the input. I'm fairly familiar with the EVA-5000 and know it's very pricey, which is why I was shying away from the 3000 since I didn't expect it would be that much less. I'll contact our reseller and see what they can get me a 3000 for.

Does anyone have guideance on the physical disk to server ratio I should look at? I'll have 25 to 35 servers on the SAN, possibly all using boot from SAN. I would think having just 25 to 35 disks would NOT be remotely enough I/O capacity to not start impacting performance. We won't be doing any heavy OLTP or things like that..just normal office type work with SMS/MOM/HPOV using SQL.

[Uwe Zessin]

Derek,

you can put up to 56 disks (4 enclosures * 14 bays/ enclosure) behind an EVA-3000. But I agree that with that many servers there is some homework needed. Can you get some I/O figures from the servers, so you can see how much you really need?

[Mike Naime]

I would also recommend the EVA over the MSA. You will have more room for later expansion in the EVA than you do in the MSA. Also, you are truly managing space, not spindles!

Your big cost is actually in the disk drives themselves. I would recommend that you purchase more of the smaller disks than buying fewer of the larger disks. 8 disks is the minimum configuration of an EVA, and I think that you will want at least 16 drives to make allowances for the overhead space and sparing. The more drives you can populate, the better. I would look at the cost difference of the 36GB disks, and compare them to the 72GB and the 146GB disks.

The 3000 model has fibre loops to connect the shelves. The 5000 uses multiple internal brocade switches (A SAN within a SAN) to connect up to 18 shelves and 240 disk drives (12 bays are left empty). This gives you 35 TB of raw storage using 240 146GB disks.

I do not have any experience with the VA line, so I cannot comment there.

We use the SNAPSHOT (Space saving) option for backup purposes. we have one entire EVA that has "backup" LUNS that are snapped every day for backup purposes.

Also, purchase the HP onsite installation. Make them deal with the licensing and setup of your EVA and San Appliance. They can get it done in a lot less time than you would spend making phone calls to get the licenses and firmware versions matching and correct.

I'm not sure if you can convert a 3000 model to a 5000 model. A good question for the sales weenies.

Mike Naime

[Uwe Zessin]

Both, the EVA-3000 and the EVA-5000 use FC_AL on their disk back-end. Last time I checked, the loop switches in the EVA-5000 were from Gadzoox. Has that changed, Mike?

It should be possible to upgrade from 3000 to 5000, although I haven't seen any part number, yet - I am not a sales weenie, well, a presales weenie at best ;-)

Last time I checked, we can't even order an EVA-3000 kernel in EMEA - we have to order a cabinet, too .-(

The upgrade will require a complete controller replacement, because the HSV100 has only one loop pair.

[Mike Naime]

I was told by me FE's and Brocade reps that they where from Brocade. I never bothered to pull one apart to check.

I can look tomorrow. I have 2 new 2C18D 5000's waiting on completion of our new data center.

[Andy McCreath]

I'd be interested to hear too, saw the threads a while ago refering to Gadzooks in MSA's. I had (rightly or wrongly) assumed that with the new 2Gb stuff a coulpe of yers back, that they switched to Brocade kit... Let us know...

[Uwe Zessin]

Andy,
we are talking about different things.

The embedded switches on the MSA1000 are front-end (although it sticks in on the back ;-) switches between the MSA controller and the servers. The 6-port switch was from Gadzoox, the 8-port switch is from Brocade. Usually, fabric protocol was and is spoken here.

Mike and I (well I at least) have been talking about the back-end switches on the EVA-5000. They connect the disk drive enclosures with the HSV110 controllers. FC_AL is spoken here (I would not call that a SAN, but I'd say that is personal taste).

My last information, which is a bit dated now, was that they were from Gadzoox. They might have changed to Brocade, now. And that is what Mike is going to look after.

[Andy McCreath]

I'm on about the same things, just worded wrongly mate...

[Uwe Zessin]

Ah, OK. I was confused when you mentioned the MSA - never mind...

[Peter Mattei]

If you want do do SAN boot I suggest reading this guide:
ftp://ftp.compaq.com/pub/products/storageworks/techdoc/san/AA-RS2UH-TE.pdf

Find more good stuff like this or the "HP SAN Design Guide" on
http://www.hp.com/go/sandesign
On page 125 of the "HP SAN Design Guide" you will find the maximum configurations for EVAs.

Cheers
Peter

[Mike Naime]

Well when I looked today, I could not find any markings on the loop switch device without tools. I did not have enough time to mess with it today.

2 of 2 FE's surveyed said "Not real sure..." when queried about the manufacturere of said switch. They did know that it was a loop switch.

Hopefully I have more time to look tomorrow. I may be able to slide out the drive shelf below it, or remove the front-plate to identify it.

[Mike Naime]

Ok, We removed one of the switches this afternoon. (Remove the cover plate, Unplug the cables, pull and remove the switch. Simple!) Nothing from the actual manufacturer on the loop switch. My FE is going to look it up for me.