Few SAN Questions.

K.C. Leblanc · 31 Oct 2008 at 13:33

I'm looking into SANs for work. A few Qs.

How do people get round the SAN switch being a single point of failure?

Who's kit do you recommend (we're quite big on HP, but I'd like to consider other options)?

How much better is Fibre Channel then iSCSI?

Origin · 31 Oct 2008 at 13:36

K.C. Leblanc said:
I'm looking into SANs for work. A few Qs.

How do people get round the SAN switch being a single point of failure?

Who's kit do you recommend (we're quite big on HP, but I'd like to consider other options)?

How much better is Fibre Channel then iSCSI?

You have dual pathing (2 switches, 2 controllers, 2 fibre cards) this eliminates a single point of failure. If you're HP, it will be the MSA 2000 either FC or iSCSI.

Depends on what you are doing with the kit as to which will be better for you.

thewanted · 31 Oct 2008 at 13:38

K.C. Leblanc said:
I'm looking into SANs for work. A few Qs.

How do people get round the SAN switch being a single point of failure?

Who's kit do you recommend (we're quite big on HP, but I'd like to consider other options)?

Each server must have two FC interfaces. You route one cable to one fibre switch, and the other cable to another fibre switch and zone them accordingly.

Dell/EMC is my personal favourite but you can have a look at NetApp too.

bigredshark · 31 Oct 2008 at 13:54

Same way you get round ethernet switches being a single point of failure, as already pointed out.

Kit depends on what you're doing, I like Netapp for the features and software extra (snap manager for virtual infrastructure is a great product). HP are good if you want masses of cheap storage. Plenty of other niche providers, 3par have some good hardware, pillar make some interesting kit. EMC are obviously a very big name but I you either like them or Netapp more. HDS are another...

Fibre Channel is infinitely better than iSCSI for a deployment of any size, if it's two servers and ESXi then fine, go for iSCSI if cost is a big issue. If it's a serious deployment then fibre channel is more reliable, faster and the established standard.

K.C. Leblanc · 31 Oct 2008 at 17:10

Cheers for the help guys.

Does anyone know of any manufacturers who make a stroage array that can be upgraded from iSCSI to Fibre Channel.

mdjmcnally · 31 Oct 2008 at 17:43

You tend to find that they have the same model but fitted with two interfaces but that they aren't swappable.

Same as you get the same hard drive with an IDE or a SATA but you can't change the IDE on the disk itself.

HP do FC versions and iSCSI versions of there SAN but aren't swappable from FC to iSCSI.

bigredshark · 31 Oct 2008 at 17:44

mdjmcnally said:
You tend to find that they have the same model but fitted with two interfaces but that they aren't swappable.

Same as you get the same hard drive with an IDE or a SATA but you can't change the IDE on the disk itself.

HP do FC versions and iSCSI versions of there SAN but aren't swappable from FC to iSCSI.

On the very low end MSA products that's true...

bigredshark · 31 Oct 2008 at 17:45

K.C. Leblanc said:
Cheers for the help guys.

Does anyone know of any manufacturers who make a stroage array that can be upgraded from iSCSI to Fibre Channel.

Generally the other way unfortunately, most of the new fibre channel arrays have options to add iSCSI connectivity.

Netapp devices support both though and I believe the license governs which ports are actually live, though if you're on a budget don't even bother with Netapp's price list...

Deathwish · 31 Oct 2008 at 18:33

What do people think of the HP MSA 2000 range ?

We are looking to get our first SAN for use in virtualisation, probably ESX. We are generally a HP house but have a NetApp NAS.

zetec452 · 31 Oct 2008 at 19:02

What are you planning to put on the san? How many VM's? How many users?

MSA 2000 is a good entry point SAN but doesn't set the world alight.

Deathwish · 31 Oct 2008 at 19:43

Well, we are currently running PlateSpin for a month to better understand the candidates but I would say initially 50 servers could be virtualised. Probably looking at getting 2 HP DL580's for a starting point. SAN will just be used for VMs (Probably ESX).

nightmare99 · 31 Oct 2008 at 20:28

MSA2000 tends to be good, for a slightly more basic box the Hitachi SMS 100 is a nice simple system.

Shaz]sigh[ · 31 Oct 2008 at 23:09

There's a few cunning questions missing from this whole discussion....

What's your budget?
What applications do you run?
What's your required throughput (IOPS)
What functionality do you want from the kit?
How much storage do you require now and how much do you envisage needing before the end of the kit's lifetime?

Going back to the original questions....

How do people get round the SAN switch being a single point of failure?

Covered....

Who's kit do you recommend (we're quite big on HP, but I'd like to consider other options)?

Really need the above answering

How much better is Fibre Channel then iSCSI?

Again, will be derived from above. Depending on the workloads, you may find iSCSI the best thing since sliced bread. To do it properly isn't that cheap though...!

paradigm · 1 Nov 2008 at 00:06

K.C. Leblanc said:
Does anyone know of any manufacturers who make a stroage array that can be upgraded from iSCSI to Fibre Channel.

Look at the EMC NS20's.

Shaz]sigh[ · 1 Nov 2008 at 10:11

The NS20 is a NAS device, the CX3 and CX4 both come with FC and iSCSI connectors. The CX4 is also modular so you can move to 10gb/8gb FC etc should you wish to in the future.

Again, it depends on the budget and what you want to do.

If it's just for VMWare then a NetApp NAS could do you dependant on performance reqs.

morfmedia · 1 Nov 2008 at 11:18

IBM DS3300 is a reasonable iSCSI box, used that in a few branch offices etc but generally hosting less than 10 VM's

paradigm · 1 Nov 2008 at 11:23

Shaz]sigh[;12810818 said:
The NS20 is a NAS device

No, its a Celera SAN device, with iSCSI and FC.

Shaz]sigh[ · 1 Nov 2008 at 14:15

The NS series is a NAS. The NS gateway series integrates in to a Symmetrix/Clariion (SAN) for the storage, the NS integrated has it's own disks. The NSX is it's own beast and I'm guessing (although I haven't touched it), is the DMX of the EMC NAS world (Vanilla can fill this bit in).

The Celerra also has it's own FS and uses DART. Whilst it does support FC/iSCSI, it's an IP storage box and thus NAS like.

K.C. Leblanc · 1 Nov 2008 at 14:47

Shaz]sigh[;12809883 said:
There's a few cunning questions missing from this whole discussion....

What's your budget?
What applications do you run?
What's your required throughput (IOPS)
What functionality do you want from the kit?
How much storage do you require now and how much do you envisage needing before the end of the kit's lifetime?

Sadly we're not at that stage yet. At the moment I just want to get a bit of basic understanding. Mostly so I can plant the right big numbers in the ICT manager's head.

We're hoping over the next few years to visualise our servers and want to use a SAN to hold the images.

However until we know what we have to spend I don't know what we can do.

The reason I asked if there were any array that supported both iSCSI and Fibre Channel was because we might start off with the array only attached to one physical server. In this situation the outlay for two FC switches might be something that could be delayed until the second server was brought online.

Thanks for everyone's input. Don't worry about suggesting expensive kit, I work in education, so the pricing doesn't necessarily correlate to what you'll find in industry.

Shaz]sigh[ · 1 Nov 2008 at 15:10

In that case, EMC Clariion, NetApp FAS, HDS AMS, Dell Equallogic should fit the bill. Compellant and Pillar have good products but not sure how they'll cope in a recession as of yet. Xiotech are worth a look in but that's just from the buzz I've seen. 3PAR are a bit OTT.

I don't like the HP EVA and the MSA is like a fishprice 'My first SAN'. I also dislike IBM's stuff at this level (ignoring the rebadged N-series).

Going out on a limb, if you're not storage guys, go talk to Dell Equallogic. It's a solid product, good price point and backed by a big player.

If you don't want to do SAN to SAN replication, talk to NetApp as well as their only real negative is duplicate licensing costs within DR sites. Be careful though cause as soon as you speak to NetApp you'll be in the FUD industry between NetApp, EMC and HDS.