SAN Solution Help

[Chuckster]

My school is looking towards investing in a SAN but we don't know exactly what would be suitable for us.

 

Firstly, let me tell you what we have and hopefully someone should be able to tell me what SAN might seem ideal.

 

First and foremost is to increase storage. Secondly is to move our VMs to something that has more resillience and redundancy. At the moment 4 VMs are sitting on a physical server running ESXi 4.0 - totalling 450GB in size.

 

The infrastructure of the school has Cat5 cabling with 100Mbps 3Com switches.

 

In future we'll be looking to have a file server to store user directories.

 

What SAN might be good for us to store all the VMs?

 

In addition to that, would a SAN come with a tape drive?

[plexer]

Your SAN could come with a tape drive if you specify a d2d2t solution.

 

Ben

[evil-tom]

Well, you actually don't have a vast amount of data there, so I'd ask whether you really need a full-blown F/C SAN, or whether iSCSI SAN will meet your need, providing you make certain that you use a decent GB switch at the back end.

 

A SAN won't solve many problems, just create new ones, so my advice is normally to ask whether you're ready to deal with the delights of live migrations of data, or whether just mirroring of data would be sufficient.

 

T

[Duke]

[...] so I'd ask whether you really need a full-blown F/C SAN, or whether iSCSI SAN will meet your need [...] A SAN won't solve many problems, just create new ones

 

I wouldn't be touching FC for that unless the fibre infrastructure was already in place, which it doesn't sound like. A SAN can solve problems, it just has to be done properly. You're right about it creating new ones though, but hopefully they'll be smaller than the existing problems!

 

Chuckster - Any idea on budgets, do you have 1Gb networking for the server infrastructure, and how long do you need this solution to last for before you get more budget to upgrade it?

 

To do everything you want from one box means going the unified storage route, which basically combines SAN and NAS. You can do block-level iSCSI to your ESXi server (although I'd recommend NFS anyway, and you'd save space there immediately through thin provisioning) and also file-level CIFS shares for your user directories. In this way you can save on buying a file server as both your users and your devices can talk directly to the SAN.

 

Plexer is right about getting a d2d2t solution. Alternatively find a SAN that supports NDMP and get a SCSI connection for it, then hang your tape drive off the back. Alternatively again, make use of snapshots within the SAN and also use backup software to get your files off the SAN to a tape drive.

 

Budgets are the deciding factor I guess. The Sun S7000 Open Storage solution is by far my preferred option currently. It'll scale from small to big, you've got replication, de-dupe's on it's way, great management, and it does every protocol you should need. It's also cheaper than the rest of the big names. NetApp stuff is nice, but extremely costly and you'll get screwed on the licensing. HP and Dell both have nice cheaper solutions. After that you've got OpenFiler and FreeNAS and you could build the box yourself.

 

If you can provide a bit more info on the above I'm sure there'll be a solution out there for you.

 

Chris

[jamesreedersmith]

Openfiler - does all of that and more.

[Duke]

Openfiler - does all of that and more.

 

No argument there, all I'd say is bear in mind your software and OS is from one place, your hardware another, and the overall solution may be from someone else again. I'm not saying it's not a really good solution - it is and a lot of people here use it - but don't underestimate the advantage of buying a whole solution from one place that will support you if something goes wrong. It's the same deal if you buy a server, put Windows on it, then put SANmelody on it. Who do you go to for support when something breaks, and what's to say they won't all just blame each other for the problem?

 

Again, not saying it's a bad idea, it's just something to think about is all.

 

Chris

[nicholab]

Unified storage you don't need file server with Sun or Netapp as their units do file sharing from the SAN box.

[teejay]

Look at the Sun unified storage, they perform really well, easy to setup and would do both your file storage and virtualisation stuff.

Don't go off the prices on the Sun site :-)

[teejay]

Forgot to say, you can get a virtual machine of the Sun Unified Storage to have a play with off the sun website.

[Duke]

Don't go off the prices on the Sun site :-)

 

+1 on that. Talk to Andy @ Cutter, Apaton @ WTL or Phil @ Sun if you're interested in the product. PM me if you want contact details.

 

Best thing to do would be to try the Sun Simulator which shows you just how awesome the BUI is. As far as performance goes, by 7410 beats most things in the same price range.

 

Chris

[cookie_monster]

We're currently running a SUN 7110 2Tb version for 8 busy VM's and it doesn't even break a sweat, we use iSCSI here mainly due to familiarity when setting up NFS would be even faster. The 7110 now comes with 4Tb as well, a 7410 would be nice but the piggy bank is running low at the moment.

[teejay]

We're currently running a SUN 7110 2Tb version for 8 busy VM's and it doesn't even break a sweat, we use iSCSI here mainly due to familiarity when setting up NFS would be even faster. The 7110 now comes with 4Tb as well, a 7410 would be nice but the piggy bank is running low at the moment.

 

Yes NFS is a lot faster and also easier to set up.

[evil-tom]

However both the security and performance knobs will need attention. That's just a delight of NFS.

T

[teejay]

However both the security and performance knobs will need attention. That's just a delight of NFS.

T

 

There is a Sun BigAdmin guide which steps you through this, really easy to do.

[cookie_monster]

There is a Sun BigAdmin guide which steps you through this, really easy to do.

 

 

I'll have to look at that at one point the lack of any security is what put me off NFS, it needs to be completly seperate, but that's for another thread.

[evil-tom]

Not really - you just apply some of the same principles as one might with iSCSI.

 

Keep them away from the public LAN.

 

T

[linescanner]

Look at the Sun unified storage, they perform really well, easy to setup and would do both your file storage and virtualisation stuff.

Don't go off the prices on the Sun site :-)

 

No do not. Edu Essentials is running at the mo and the 7000 is running a big discounts.

[cookie_monster]

Yeh it's just that 2 devices can't mount a LUN so it can't be connected to by another person while in use, you can also password protect it and vlan or physically seperate. NFS doesn't have password security by default or a way to lock out access so you have extra planning for security. I'm merely mentioning it as allot of people don't realise this when planning not as a comparison.

 

Securing NFS

Edited January 15, 2010 by cookie_monster

[DMcCoy]

Yeh it's just that 2 devices can't mount a LUN so it can't be connected to by another person while in use, you can also password protect it and vlan or physically seperate. NFS doesn't have password security by default or a way to lock out access so you have extra planning for security. I'm merely mentioning it as allot of people don't realise this when planning not as a comparison.

 

Securing NFS

 

Yes they can. You will however need a cluster file system to make sure the devices know what they are doing. I've not got a Sun box, but there shouldn't be any restriction to the number of devices accessing a LUN, all of my servers have access to all LUNs on two different SANs.

[evil-tom]

Try OCFS2

 

T

[AIT]

Openfiler - does all of that and more.

 

If you are looking for redundancy, openfiler with redundant second box. We use openfiler (slightly tweaked) doing this and works perfectly can reboot individual storage boxes and no iscsi connection is affected.

[cookie_monster]

Yes they can. You will however need a cluster file system to make sure the devices know what they are doing. I've not got a Sun box, but there shouldn't be any restriction to the number of devices accessing a LUN, all of my servers have access to all LUNs on two different SANs.

 

 

It could depend on setup. When Xenserver connects to one or our LUNs it's locked and won't let anything else connect, more than one device can connect but only if it's part of the same pool, if I try to connect to the LUN using another Xenserver it fails.

[DMcCoy]

It could depend on setup. When Xenserver connects to one or our LUNs it's locked and won't let anything else connect, more than one device can connect but only if it's part of the same pool, if I try to connect to the LUN using another Xenserver it fails.

 

XenServer doesn't use a clustered file system, it leaves that up to the end user / storage provider instead.

 

Hyper-V (R2) and VMware have their own clustered FS/solutions so would both connect to the same LUN

[cookie_monster]

That will by why then.

[apaton]

NFS doesn't have password security by default or a way to lock out access so you have extra planning for security. I'm merely mentioning it as allot of people don't realise this when planning not as a comparison.

 

You can lock NFS share down on the S7000 to an IP Address or Network IP range, but there's no password protection. Check this thread

 

I would recommend a dedicated VLAN for XenSever/VMware and NFS, which address most security issues.