San decision help!!

[[Darkend]Viper]

Hi people,

I've got a few questions regarding a new SAN we're wanting to implement. We're currently using esxi 4.1 free version with direct storage, and our sql server isn't virtulised. We have't got any fault tolerance between our esxi hosts so looking at new servers and storage unit.

I;ve got the servers sorted, so no probs there. But what is really confusing me is the SAN. We've had 3 quotes for 3 different systems, the first an EMC VNXe san, a dell powervault md3220 and a hp version.

Now the EMC is a unified storage system so will do windows shares from it, the other 2 won't. It's also an iscsi unit. Now what i'm wanting to know is will this slow it down compared to the other das sas 6gbp/s units?

Has anyone any experience of any of these units?

We will be virtualising the sql server, 20gb database, maxium 100 users at once. along with a load of other servers like dc's, web, wsus, sophos.

This is for a school environment, with 440 client pc's, 650 users, of which maxium 380 accessing it at once.

We're after a unit that will perform well, I like the EMC as it's got 15k sas disks for the virtual machines and 7.2k NLSAS for the storage of windows shares. The others are 10k SAS drives. We're looking for about 10tb of space in total.

Any help is appreciated.

 

[[Darkend]Viper]

Well i've still made no head way, been trying to get my head round the benefits of a DAS as opposed to a unified storage unit, and the price differences between, nearly 25k!!! But to be fair the DAS only has 10k disks where as the unified unit has 15k disks.

I understand the 15k disks will give superior performance for things like SQL and exchange due to their higher IOPS?

 

[[Darkend]Viper]

At the moment it sounds like you're looking at solutions for a problem you don't know the size and shape of.

How many servers are you running currently?
I say this because there is a point at (roughly) 8 servers, where direct storage [with a robust backup solution] makes more sense than having a SAN.

A 20GB SQL database doesn't sound too bad, but that doesn't tell us anything about the usage of the database - Peak IO, Average IO etc. consider this on top of what Skilldilliplop already said about RAM utilisation on SQL servers making them poor virtualisation candidates.
Is there an IO peak at 9am when the lessons start?
Are the peaks spread throughout the day at the start of each lesson?
How high are the peaks?
For instance, if they are awkwardly high (1000+) local RAID1 SSDs may be preferable.

Which version of Exchange are you running?
How big are the mailboxes and how many?
Exchange 2010 will gobble up at least 20GB of RAM if given the opportunity, this makes it another awkward virtualisation candidate without proper foresight.

Web, WSUS and Sophos aren't very intensive (assuming light / basic web services), so no problems there! They may need their SQL instances restricting in memory usage, but nothing that good practice doesn't already state.

I love SANs but storage needs a holistic approach.
The £/GB for SANs is higher because of their management and advanced functionality, but do you really need those?
I know High Availability and Fault Tolerance sound nice, but a school is not a 24/7 business.

Edit: If you have a blank cheque for a new system, definitely go with EMC and a load of beefy servers.

For the SQL it's peak is twice a day when about 100 people login for attendance, and thats am and pm, for maybe 20 mins!!

We're currently running 13 servers, and am planning on keeping our TS server physical along with a DC. Just purely for backup options, these are in a seperate building.

My main concern is the SQL database, as it's slowish now on some machines, but not sure if it's the server or client, it's hard to pinpoint when the same hardware and same image is used and there's a difference, but not had time to check.

DAS is seeming to make the more financially viable option rather than a SAN. But going to get the supplier to quote for 15k disks not 10k. And maybe a bit extra storage.

 

[[Darkend]Viper]

We bought a VNXe 3300 with 12TB of storage (6TB 15k, 6TB 7.2k) ~ £30k

Virtualized the 20 or so servers at the same time into 3 Dell R710 hosts with 48GB RAM each.

VMs are all Server 2008 R2, roles include

2 x DC (4GB RAM)
2 x Exchange 2010 (16GB RAM)
1 x SQL (SIMS 16GB RAM)
1 x WSUS (4GB RAM)
1 x Application Server (4GB RAM)
1 x ISA Proxy (2GB RAM)
1 x Print Server (2GB RAM)
1 x Bromcom Register Server (4GB RAM)
4 or so Linux boxes (Web servers etc) (1 - 4GB RAM)

Not had any issues with it so far. Using vSphere 5 with NFS linking the SAN to hosts (was quicker than iSCSi on bench tests)

CIFS shares straight out to windows clients work a charm.

This is virtually identical to us!! The specs of the VNXe are even very similar.

Can I ask what sort of speeds you get from the vnxe?

I'm guessing from sims and bromcom, your an education establishment?

 

[[Darkend]Viper]

Just after a general idea of how fast serving files via cifs is and how fast the nfs connection is.

Have you found it's been worth the cost? and do you know what other units you were looking at when choosing?

 

[[Darkend]Viper]

Yeah your a bigger school, we're just wanting to get something that will last 5 years, without costing the earth and be quick. I know in this sector quick and costing the earth don't go together!!

We've got 700 users, 440ish machines, and high expectations!! They expect sims to load instantly!!

I'm trying to find anything I can out about having this over the dell powerevault, as i'd prefer this as it means one less server needed to virtualize!!