SAN or Server Cluster

Hi Experts.    I'm a storage novice but after a year of playing around with a stand alone server (DAS?) running hyper v and a handful of vm's, I'm ready to move up to a more redundant and scalable solution in a production environment.   Before making a $30k pitch to the check writers I was hoping to get some advice from you.  

You can correct me if I should be looking at another option, but in short, I have a quote for a Powervault MD3220, 6 hard drives, and 2 6gbps SAS controllers and two servers running in HA for about $30,000.  I can add another 2 HA servers or 4 non HA later.     Another quote is for 3 servers in a cluster is around the same amount.  

Other options I have considered in order to reduce sticker shock:   1)go down to one server, for now, on the SAN and live without HA.   I would still need a fast restore plan  2) go down to two servers on the cluster and reduce my vm capacity by 1/3.

One trigger for needing to make this move now is that our new office phone system will be running on a Windows 2008 r2 vm, and that needs to be as redundant, or HA, as possible.   There will also be a few other vm's related to the phone system that do not need to be HA.   Like, I'm ok with 30-60 minutes of downtime on those, although I would like the restore process to be straight forward and well documented so that I'm not the only one that can do it.    Other future vm's would be a file server, sql server, terminal/citrix servers, etc.   I was going to put exchange on this platform but i think we'll go with a hosted solution instead.

We also have a co-location facility on a 100mbps private line where I may want some replication to occur down the road.

Can you give me some guidance on the value of the SAN appliance versus a server cluster?   On this quote we are only using 6 of 18 bays and 4 of 8 connections on the SAS controllers, leaving room for some growth.  That seems like a no brainer, but I could also do this a lot cheaper by just setting up a two server cluster, or one server with the best snapshotting/backup tool i can get.

Thanks in advance

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Aaron TomoskySD-WAN SimplifiedCommented:
I wouldn't really call this a San since it's direct attached storage. It is a nice way to avoid storage network traffic but if you need to scale to more hosts it won't do that.

It depends a lot on your situation and future needs, but Personally I lean toward an actual San/nas over the network with "dumb" servers as hosts that are basically just CPU and ram.

For the San part, you can do a small all ssd array (intel 3700 are very nice)  for the vms, and big cheap slow sas/sata for large file storage. E.g. For an FTP server, attach the os disk to the ssd array, and and a d drive to the spinning array. That can significantly lower costs compared to a large 15k rpm setup.

This keeps the system very flexible so you can add a host cheaply if you need CPU/ram, or increase storage if you need that.

Also, whatever you do, don't forget about backups. Many San systems will have automatic replication to a second system and some have snapshotting capabilities which can be really handy. Better to start with a smaller scalable architecture with a good backup than a larger setup that is less flexible and no backups.
Max SandoStorage EngineerCommented:
Can you provide any more information on your NEEDS?

I initially like where Aaron is going and also prefer a true SAN/NAS, but I work in storage so I might be somewhat bias. As Aaron said an actual SAN solution will have some nice bells and whistles especially when you start talking about replication.

If you do look at solid state for the VM portion the Intels are nice but there are other drives that perform better in some areas that are much cheaper.

If you can give us a bit more information on requirements we can probably toss out some more solid ideas.
Aaron TomoskySD-WAN SimplifiedCommented:
Try to think of how you would solve a problem/situation:
Your vm hosts are out of ram/cpu:
when your using a cluster or DAS, you have to get some specific stuff. For a cluster, if you want to add it's disks to the pool, you need to buy the disks, raid card, etc... For a DAS, you at least need the hba, and you need to have ports on the storage appliance
When using a san/nas, you can get a 2u supermicro with 2x4core xeons and 128gb of ram, with dual 10gbe onboard nics for about $3500. Toss in a usb stick or sata drive to install the os on and add it to your environment. Feel free to buy a dell server, it's still nice to be able to just get whatever and not worry about making it part of the cluster or having special hardware to attach it. Your vm hosts are just ram and cpu.

As to the HA ability of the md3220, it's just a second hba connection incase a cable or hba goes bad. When you are going virtual, HA is the ability to have an entire host die and the vm just spins up on another host. Now thats HA.

Then think about if your storage dies what you would do:
cluster: you don't really care as each host is part of the cluster so you don't have a seperate storage that can fail. if you are setup to only tolerate one failure, you are no longer protected, and things may be slow for a bit, but nothing really really bad happens.
das: you are sol. better have some spare parts around and be able to plug in all your direct attached cables. the entire inventory is down until you can get this back online.
san/nas: if you are replicating to another one onsite, you can change some ip addresses and be up and running with only a small amount of dataloss (the time between replications). To have two of them in an HA setup starts at 50k, so being ok with a few min of downtime can save a TON of money.

So clusters can be cool for small needs. A have found that (vmware sorry, I don't really use hyper-v much) for some clients, a vmware essentials plus (3 servers) and vsan (use local storage on clients to make one virtual san) is a really nice option.
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I am not even sure how you can spend so much $$$ and get so little. You can get two servers, load them with disk and maybe SSD and then use Starwind Software to turn them into a virtual SAN. That would be cheaper and more reliable than what you are talking about. You could have two servers and just use the Hyper-V replica feature to keep copies of your VMs available on the second host.

You need to know what kind of capacity and performance you need before you go looking for storage. Hosting Exchange is probably a good idea.

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alexsupertrampAuthor Commented:
Thanks for your responses.    I think you reaffirmed my understanding that the md3220 appliance provides much more scalability than a server cluster.  For instance, once you configure a server cluster, which can cost as much as an md3220 appliance and two servers, your configuration is set in stone.  No disks or volumes shall ever be added or changed.   But, allegedly, you are more redundant.   Correct?

On the subject of the md3220 redundancy; with two power supplies, two controllers and two HA hosts and proper raid configurations, am I not rather well covered?

I did state my current needs already, but I do like the ability to add more storage and hosts on the appliance.  Our needs fluctuate quite a bit.

I have looked into vm essentials plus before as well..thanks for reminding me about it.     And Kevin, I will look into the  Starwind option you mention...that's a new one to me.  

Thanks in advance for your replies.
Aaron TomoskySD-WAN SimplifiedCommented:
I thought something like starwind was what you meant when you said cluster. a vitrtual san based on the storage of the local computers.
alexsupertrampAuthor Commented:
aaron, you are correct.  i'm just not familiar with Starwind.
Alex, I have no idea what you mean by a server cluster because you don't seem to refer to it like most of us do. When you have multiple servers accessing "shared storage" and hosting VMs, you have a server cluster. It doesn't matter what that shared storage looks can be FC, SAS, iSCSI, NAS, virtual SAN, virtual NAS, etc. If you are using a SAN you are almost always going to be using a server cluster. If you don't have a server cluster you should not be using a SAN. The MD3220 is not a SAN, is is external local storage. Instead of a MD3220 attached to two servers, I would buy two Dell R720xd servers. Each of those servers can hold more drives than the MD3220, and they can run your VMs as well. Add in StarWind Virtual SAN and you can run dozens of VMs without a single point of failure in the storage or computer layers. If one server went completely down your VMs will reboot onto the other node without any loss of data because all changes get mirrored to the storage on both hosts.
alexsupertrampAuthor Commented:
kevinhsieh, ok, I'm trying to get up to speed on the terminology.  i envisioned a server cluster as a group of servers sharing onboard storage, not attached to a storage appliance.    this is one example given in some documentation i read recently.

isn't it true that i lose scalability with the virtual san scenario that you suggest?   like, i will never be able to add more drives or another physical host?   i have heard people suggest going with vmware essentials or other storage appliance-less solutions, like you are suggesting, so i'm just trying to get my head wrapped around why one chooses a storage appliance over a host only solution, and vice versa.    if you could comment on that, that would be great, then i'll wrap this up.   thanks again.
You can add disks, and you can add nodes with storage, and you can probably add nodes without local storage. I don't know why you would ever need more than two nodes at your size infrastructure. The R720xd can hold 31.2 TB of raw 10K RPM storage. It can hold even more capacity when using 7.2K NL SAS drives which can be combined with SSD performance drives which is what I would recommend. You can very cost effectively put 384 GB of RAM in the system, and the system can currently support 1.5 TB of RAM. A Windows datacenter license to license an unlimited number of Windows Server VMs costs many thousands of dollars so it makes sense to take maximum advantage of Windows Datacenter licensing and to not use more licenses than necessary. IMHO a two node setup for you is perfect, and that can scale up far beyond what you are going to need in the near future. You could seriously run over 100 VMs on just a single server. The second server is there for high availability.
alexsupertrampAuthor Commented:
Thanks for the information.  I know a little more about my options now.
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