Affordable iSCSI SAN

[Tony Campney]

Looking for a iSCSI SAN in the ballpark of 7TB raw 15k SAS/FC storage. Budget will allow around 30k (give or take a bit). The plan is to boot either ESX or Hyper-V images from the SAN. Will probably be around 5-10 physical hosts with aroud 30-40 VMs. VMs will be things like Exchange, SQL Server, SharePoint, AD, file server, terminal server, web servers, and other general app servers. We'd like to plan support for 100 users.

Our highest use servers in terms of IO(exchange, sql, file server) combine for about 12MB per sec total I/O on average(roughly 7.5MB reads and 4.5MB writes). Sadly I haven't yet done perf monitoring on all server to know totals of all servers.

Main question is for the above requirements (including budget) is the StorageWorks 2012i Dual Controller Modular Smart Array the best choice in the HP line? Does it seem up to the tasks outlined above?

One of my main concerns is the 2012i says it only supports 16 hosts. Offerings like the Dell/EMC AX4-5i support up to 64 hosts. We are an HP shop and would like to stay exclusively that way, but at the same time need to find the best product for this task.

Any thoughts or help would be much appreciated!

[IBaltay]

Hi, maybe the best HP choice for this is EVA 4400:
http://h18006.www1.hp.com/products/storageworks/eva4400/index.html
for e.g. the following reason:
a) iscsi support
http://h18006.www1.hp.com/products/storageworks/evaiscsiconnect/index.html?jumpid=reg_R1002_USEN
b) SAN support (if needed)
c) flexibility to act also as a NAS storage with the HP Polyserve filer heads
d) very good price/performance ratio

[Tony Campney]

Thanks for the quick reply. I've been trying to avoid any "enterprise" solution as it seems licensing just kills you in pricing. You want more disk space? Pay us $$ for the new drives and then pay us $$$$$ for a capacity upgrade license for the unit, etc, etc. I see with the 4400 if you want to move past 16 hosts (is that just physical hosts or would each VM count as a host?) you need to license additional hosts.

Having to keep paying more for something you've already purchased if you decide to use it differently just annoys me to no end :-)

My initial concern with the 2012i 16 host limit was it was because performance wise it just cannot handle more. Seeing the 4400 iSCSI situation, perhaps this is just a licensing issue to get you to upgrade to more expensive systems?

[IBaltay]

here is the eva iscsi connectivity user guide:
http://bizsupport.austin.hp.com/bc/docs/support/SupportManual/c01519273/c01519273.pdf

here is all eva related iscsi documentation:
http://h20000.www2.hp.com/bizsupport/TechSupport/DocumentIndex.jsp?contentType=SupportManual〈=en&cc=us&docIndexId=64179&taskId=101&prodTypeId=329290&prodSeriesId=1833384

Note:
try to consult the pricing (iscsi licensing included) with the local HP representative, to see why the EVA is said to be the "enterprise" at the "low entry" price pls :-)

[Vincent Steeb]

Tony,

Your correspondent works for HP! We just bought a 4400 with 25 TB....to use with VMWare on HP blades....WHAT A BAD DECISION!
You want to give Dell, or EMC a call as you indicated as the iSCSI opportunities are VERY limited with this system....

Building a SAN
into A Pile of Bricks
Vincent

[Tony Campney]

Vincent,

Could you provide any insight into the issues/weaknesses you have seen in your HP system? Performance? Management? Interoperability? etc?

Appologies if an HP hosted forum isn't the proper place to ask such a question, but as previously stated we are a loyal HP shop and the best way to keep us that way is to ensure we don't buy a HP product that cannot do what we want. So from a customer satisfaction standpoint at least I'll assume such discussion is OK.

[Rob Leadbeater]

Hi Tony,

Is there any particular reason that you're looking at iSCSI over Fibre Channel ? I'm guessing cost ?

Taking a look at the latest SAN guide from VMware:

http://www.vmware.com/pdf/vi35_san_guide.pdf

will show you that none of the HP supported arrays support Boot from iSCSI.

The last time I looked at ESX server (which is a while ago it should be said), it was a little limiting in what it could do with the storage on iSCSI. A number of the HA features, only worked with FC...

Hope this helps,

Regards,

Rob

[chris barnett_2]

I would be a bit carefull with what Dell or EMC say. HP say the Fibre Channel version of these arrays support upto 64 hosts, the iSCSI upto 16. Dell and EMC lump togeather both the FC and iSCSI arrays on the same data sheet. I suspect the Dell and EMC arrays support the same as the HP ones. HP are more up front about things. I dont see why the EVA4400 iSCSI offering is limited, has upto 4 Gb ethernet ports same as everyone elses and 4 ports of Fibre Fhannel but with 26TB of storage and a c-Class blade chassis I would never recommend iSCSI as a solution, mix and match maybe. Fibre Channel for high I/Orequirements , iSCSI for low I/O requirements. Personally i have never been convinced by the iSCSI argument, Fibre Channel is reasonably cheap these days and well understood. Think iSCSI has missed the boat. fibre Channel over ethernet will kill it but it's still an emerging standard.

[Tony Campney]

We basically have 4 reasons for choosing iSCSI over FC.

1) Cost. Not exactly the main reason, but of course is a factor.

2) Internal knowledge. Currently only two dedicated IT resources internally and neither have any experience with FC. We are already streched very thin and adding new technology is a last resort.

3) Complexity. We have office in Cayman Islands and Toronto. If we want to do replication that would require FC-to-IP switch, etc that just adds complexity we cannot handle (see point 2 above)

4) External knowledge/supply. Main office in Cayman Islands means FC supplies and experience isn't that easy to find. FC HBA or switch fails, we'll be waiting for a few days for a new one. Ethernet switch or NIC fails we can get a replacement in a couple hours (even if it is a temp solution until higher quality version can be shipped in).

We don't have heavy IO requirements so it seems iSCSI will work for us today. A few years when 10gig ethernet is in our price range, it certainly won't be an issue.

[Tony Campney]

Also, about booting from iSCSI. Correct me if I'm wrong but I belive that issue is with actually booting the ESX host itself from iSCSI. Booting ESX guest VMs from iSCSI has been supported for quite some time (at least ESX V3.0 I belive) unless I am mistaken.

[IBaltay · Accepted solution]

Hi all,
it seems that i cannot add any other comment here :-)

[Rob Leadbeater]

Hi Tony,

> Booting ESX guest VMs from iSCSI has been
> supported for quite some time

Correct... I read your original post to mean that you were looking to boot the ESX boxes themselves from the SAN, rather than the VMs.

Cheers,

Rob

[Uwe Zessin]

> Booting ESX guest VMs from iSCSI has been
> supported for quite some time

But that requires third-party software (emBoot), because a VM does not have an iSCSI HBA.

[Tom O'Toole]

wouldn't you just boot the guest oses from the esx host OS provided disk, rather than directly to a 'disk' over the network? that seems like a no-brainer...

[Uwe Zessin]

Sure ;-)
The standard way is to put the boot disk as a virtual disk container file (.vmdk) onto a VMFS file system. A VMFS can be stored on an DAS (local storage) or SAN (Fibre Channel or iSCSI attached LUN).

If you twist your mind a bit, you can claim that you are 'booting from iSCSI', even if it's an iSCSI attached VMFS ;-)

[Tony Campney]

Uwe, yeah that is what I was planning. Too much different terminology with storage :-) So I guess you can say instead of "booting from iSCSI" I will be "booting through(?) iSCSI".

[Tony Campney]

Main point being the guest VMs will boot from shared/centralized storage which is accessed by the physcial host via iSCSI.

Anyway, back to the original question (in short version). Seems for my price range the 2012i and the "all in one" systems are the main options. 2012i seems the better system for my needs. Anyone with experience with this to validate if it will be up the the specs throughput in the original post? Thoughts on 2012i vs EMC AX4-5i as far as performance and scalability as that is another system that seems in my price range?

[Uwe Zessin]

Tony,

I really, really suggest that you try to get an idea how many IOPS (read/write) your environment will require so that you can get an idea how many disk drives you need.

I've done some tests with a non-HP iSCSI array and could easily fetch 80 MegaBytes / second via the VMkernel iSCSI initiator. Using the Microsoft iSCSI initiator within a virtual machine, two paths and round robin load balancing, I was able to fetch about 180 MB/s.
So the servers will not be the problem. The question is whether the storage array can perform well and whether it has enough disk drives.