Why use ISCSI for Virtualization.

justinoleary911
justinoleary911 used Ask the Experts™
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Im in the process of building a HyperV virtual infrastructure and Dell is telling me to use a $17,000 equal logic device to host the VM's.  Is this really what i need, whats the big advantages of using an equallogic vs an internal fast raid array. besides the fact that if the server goes all the VM's are on a SAN.  Can someone tell me why we should spend this much to virtualize 10 servers?
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Commented:
you do not have to use ANY shared storage iSCSI , Fibre Channel or NFS.

you can use local disks to host your virtual machines, but if your single HyperV host fails, all your VMs will be down.

If younuse two hosts and shared storage, you will have higher availability.
To add on to the previous comment. It really just depends on what your business requirements are and your plans for future growth. There is no technical reason why you cannot virtualize without shared storage. With a comprehensive Backup and Restore strategy you may be able to satisfy your business requirements without it

However, shared storage may help you to meet your internal SLA's and RTO/RPO's. Also you do get certain other features, such as the ability to live migrate or power on servers on another host in the event of failure.

The best way to approach this would be to have Dell outline what features you gain in the overall platform by adding shared storage. Then analyze that to determine if it's something you'll need (now or down the road). Keep in mind where the money is! The vendor always has great incentive to add in storage!
That's a lot to spend on a SAN to host 10 VM's.  I would consider looking at other vendors in a lower price range, QNAP and Synology may be something to look at, they both do VMware/MS certified SAN boxes that would be suitable.

I use 2 Synology RS3412xs to provide iSCSI to an ESXi cluster hosting 20 VM's.  The internal RAID on the servers is faster, but its not noticeable in day to day usage by end users and the flexibility that shared storage gives me makes iSCSI win.

Also as recommended above I would also get 2 hosts to provide some high availability and if you do decide to use iSCSI use jumbo frames on it from the start.
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Author

Commented:
can someone tell what is so great in a smaller enviroment about iscsi.  the ability to reallocate storage, or what.  For the price of an iscsi device i can get to servers put them in different locations and run doubletake availability over a wan link.  now i have server failover and site failover.  if i spend $20,000 on an equallogic and theres a fire the equalogic is gone with the server.  can someone explain to me the reasons a medium sized business would benefit from an iscsi device rather than the scenario im brining up.  i can see if we were looking at virtualizing every server and every workstation then i can see the need to centrally manage everything.  I just want to know if I'm missing something this equal logic does for $20,000
Lee W, MVPTechnology and Business Process Advisor
Most Valuable Expert 2013

Commented:
DoubleTake is not on par with a SAN.

Failover with doubletake can be problematic when you fail back.  And at $2500 per server, I don't see how $25,000 is less than $17,000.  Unless you think you'd protect the host OS with it?  Are you sure that's a supported configuration?  It's also an all-or-nothing failover.

And 10 servers is NOT a small environment.  ONE or TWO is.  

Now, if you wait (deal) with the risk for a few months and then upgrade to Server 2012, Hyper-V in 2012 offers replication features which effectively act like doubleTake. (Check out the beta and play with that to better understand).

Further, you could just buy a third server with storage and run Windows Server/Storage Server as that supports iSCSI Target functionality.

I have my doubts you'll recognize the value if you can't see it already with 10 servers.

(The advantage to an EqualLogic box is that it should be optimized and supported for SANs and you'd have ONE vendor to go to for support.  (Maybe two if you could MS and don't get a Dell support package).  Stop and think (better still, do a proper cost/benefit analysis) about how much lost productivity the business would experience if all servers were down).
Top Expert 2014

Commented:
If you want to use the internal bays and have high availability at cheap hardware cost you can use a virtual SAN appliance; HP, Datacore and Starwind have products; there may be more*. It's a virtual machine that makes the local disks into an iSCSI target that hosts all the other VMs, and they all have high availability so the disks in one host are mirrored to those in the other. a third node is normally needed to avoid split-brain syndrome but any old PC is powerful enough for that as it's just there to provide quorum.

*I don't think Open-E hav a Hypr-V VSA, they do have a VMware one.

Author

Commented:
ok leew after all the stuff you said finally at the bottom you said, the value of a $20,000 equallogic is that i can go to 1 vendor?!  the server is dell as well i can still go to one vendor.  your saying i cant see the value, yes please tell me something that makes it work $20,000.  Ive done the scenario with doubletake and it worked more than fine it took about 15 minutes to failover to the DR site.  It doesnt seem like anyone can tell me what are the major benefits of the $20,000 piece of equipment if the server craps out is the virtual enviroment going to keep running on the equallogic I believe Ill have to replace the server.  if theres a disaster at the primary site the server and the equallogic are both gone.  so tell me why leew doubtake scenario with 2 servers is not on par with a premise based equallogic

Author

Commented:
also doubetake availability for hyper V is a little over $3,000 a bit less than the $25,000 quote you have leew, oh also supports unlimited VM replication.  so please tell me why i need to go with a SAN for this scenario
Top Expert 2014

Commented:
At least your Windows licensing costs will be reduced with DoubleTake since you won't have to pay license for each VM on each server.

Author

Commented:
I've requested that this question be deleted for the following reason:

did not get any reason to use iscsi for a small business that has a small virtual environment.  
Top Expert 2014

Commented:
You want to delete because none of us would back Dell sales up with selling you an equallogic array that you don't need? Would you be happier if we made up some reasons?

You can take hardware snapshots on the equallogic, you can't do that with local disks; not much extra functionality for $17K though.
Lee W, MVPTechnology and Business Process Advisor
Most Valuable Expert 2013

Commented:
You can't see the value.  I'm sorry.  There may not be value to your company.  If your servers fail and your company loses $50,000 in lost sales and productivity was the $17,000 item worth it?  MAYBE.  You'll never know.  You're reducing odds going with proven, practical, STANDARD tools.  You can argue doubletake if you want.... just like someone can argue Symantec is fantastic if they want... won't change my opinion.  I spent YEARS piecing together half-assed systems because why should I spend the money on something I know I'm skilled enough to jury-rig myself?  Answer?  Because I sleep better knowing it's someone elses problem if it doesn't work and I'm not going to have answer tough questions if it fails - I went with the proven technology.  I learned that over time.  I suspect you will too... or you'll end up in another field.

Best of luck to you but just because you didn't like our comments doesn't mean we didn't answer your question.

Author

Commented:
if the host server fails is the SAN going to still run all the servers on the network?  No it will not.  and you can take snapshots without a san its called 2 different raid arrays inside the server.  and this is exactly why i wanted to delete the question because youre still not telling me any real reason to have a san in this situation.  i can care less about dell sales,  this is just the san soultion presented by dell.  if i tell a customer get a server and a san and tell them, hey its cool if the server dies youre screwed but i have some cool fuctions with the san. or tell them spend your money on 2 servers and a failover soultion if one dies you have a backup at another location as well.  so leew you can say im wrong and we should have a san over another server but you still have yet to make any argument as to why.  if you can tell me one reason why in this scenario a san is better than 2 servers, id love to hear but i think youre just going to keep saying if i dont see the value now then i never will.  well id love to leew just give me an actual reason.
Top Expert 2014

Commented:
>"you can take snapshots without a san"
Cleverly removed the word **hardware** from that quote didn't you.

>you[']re still not telling me any real reason [not] to have a san in this situation.
Yes we have given you good reason not to get a SAN, $17k's worth.
Top Expert 2014

Commented:
I actually agree with the asker, they may be able to get away without shared storage and clustering. A main host and a backup one might be the best way to go, they don't even need to use Veeam or doubletake replication assuming they back up properly. Failover can be implimented by unplugging the data disks from one box and plugging them into the other if you do it right and if that doesn't work it's back to the tapes for a restore.

But deleting after arguments as to why use shared storage (and why not) have been presented does seem a bit cheeky.

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