NAS: the next best

[Yogeeraj_1]

Dear experts!

I have a SAN subsystem has the following specifications:

Performance data
================
Maximum sustained I/O rate from cache 11,800 I/O per sec
Maximum sustained I/O rate from media 4,600 I/O per sec
Maximum sustained transfer rate from media 170 MB/sec

Host/drive connections
======================
Eight 2-Gb Fibre Channel host-side connections
Four 2-Gb* Fibre Channel drive-side connections

14 x 36GB FC disks (in which the usable area which far more than i will need in 5 years!!)

This is not HP!

For my next purchase, i want to choose HP.

What are the better solutions that i should look at?

thanking you in advance for your replies!

kind regards
yogeeraj

[Pete Randall · Accepted solution]

Yogeeraj,

HP's latest greatest is the EVA series, but I found them to be prohibitively expensive! I went with a VA7410 and have been extremely happy with it:

http://www.hp.com/products1/storage/products/disk_arrays/midrange/va7410/index.html


Pete

[Dave Hutton]

We currently have an EVA3000 and 2 EVA5000's and its extremely easy to use.

From an administrative standpoint it's easy to present and carve up disks. The EVA is constantly active, even if thereâ s no disk I/O from hosts. It's trying to level out the data and move hot spots, to optimize performance.

But you can't define raidsets on the backend to stripe the way you want it. Which is good and bad. That being said you don't have to worry about it either. The newer 4000/6000/... versions are supposed to be even faster then the ones we have.

Adding disks to it is very easy and really reliable for us. We have lost a few disks since we've had them over the last year or so. But it doesn't even hick-up it just keeps moving until we can get a replacement disk.

For redundancy it reserves a spare disk, along with it creates RSS groups.

Depending on the model you may look at, you can add a boatload of disks, so you can scale them way up.

[Yogeeraj_1]

hi again!

thank you for your replies.

Where can i find comparable performance data for EVA/VA?
(because i would not like to go for a NAS that gives me lower performance...)

more suggestions are most welcomed.

kind regards
yogeeraj

[Uwe Zessin]

Yogeeraj,
a NAS box and a SAN box simply serve different business purposes.

NAS is about sharing of files on a network - usually a LAN.

SAN is _usually_ about sharing of block devices on a Fibre Channel based storage network.

They are not enemies and in the HP world (and some competitors) you are even free to combine them. You can connect a 'NAS head' to a SAN box. The NAS box serves files to the cliends, but stores them on the SAN box. The SAN box can be used concurrently by other servers, e.g. for databases.

--
For 8 host ports you would need the EVA-8000 unless you can accept a 'scale-out' to two smaller arrays.

It is highly unlikely that you can achive the desired performance figures with just 14 disks:
4600 IOPS / 14 disks = 328.5 IOPS per disk !!

[Bill Hassell]

NAS is a cheaper solution in many cases, but be very careful about performance. All your performance inside the array is strangled with this tiny pipe called a LAN. 100Mbits is really 10Mbytes when *fully* saturated. And 10Mbytes/sec is way slower than most modern disks. If you can use a Gb LAN, you may have reasonable performance but this all depends on whether there is one client for the entire array, or many clients all trying to use the same little wire to the NAS box. Now if the NAS supports multiple LAN cards in the box, then a reasonably fast switch may be able keep data flowing pretty quickly.

SO I would look at NAS through the network pipe and ignore the internal disk and cache performance as this won't make it through the network at those speeds. But if a large, lowcost storage box is needed and perfromance is not the highest priority, NAS looks pretty good. Be sure to get the HP-UX NFS book by Dave Olker for tuning your client(s).

[Yogeeraj_1]

hi again,

thank you for the clarifications about NAS.

In fact, i had wrongly mentioned about NAS when i wanted to mean SAN.

So, which one of the HP SAN will be giving me better performances? (taking into consideration that our Disk space requirements is very low -- 1 TB would be too much!!)

regards
yogeeraj

[generic_1]

xp series is the best san from HP :)
Its faster and is designed for mission critical data.