I'm considering getting a fully loaded Drobo Pro and using it to store VHDs that would run our on a pair of Hyper-V host machines. The host machines would connect to the Drobo Pro via iScsi.
Anyone have experience with the Drobo Pro and Hyper-V? My main questions/concern is about speed - is the Drobo fast enough to handle say a dozen VHDs all running concurrently?
I am on the Product Marketing team at Data Robotics, so I'm hoping I can shed some light on the questions around the DroboPro, performance, and virtualization.
Regarding DroboPro performance, there are a few independent reviews that have posted performance numbers. One is GeekBrief.tv and the other is the LA Final Cut Pro User Group.
Here is the LAFCPUG review and the Geekbrief one can easily be found at Geekbrief.tv
http://www.lafcpug.org/reviews/review_drobopro.html
Feel free to check out the full reviews. In terms of iSCSI performance, LAFCPUG used a tool called Blackmagic and saw ~80MB/s read and ~70MB/s write. GeekBrief.tv used a tool called AJA and saw ~74MB/s read and ~79MB/s write. Burst speeds will certainly be higher as darthcoder alluded in his post, but 80MB/s is close to the limit in terms of sustained throughput on a single GbE.
One thing to note in the Geekbrief.tv review is that there was no mention of attaching the DroboPro directly to a switch which is very easy to do by simply assigning a fixed IP via the USB management port prior to attaching the switch. The latest version of our Dashboard management software has support for multi-host and up to 16 x 16TB virtual volumes.
Regarding virtualization, Data Robotics is in the process of certifying the DroboPro with VMware ESX which is the top priority due to market share. Having said that, we will be doing similar certifications with Microsoft Hyper-V and Citrix XenServer once the VMware certification is complete. While we have not yet officially performed testing with Hyper-V or Xenserver, we are aware of several customers that are successfully using Drobo and DroboPro with VMware, Hyper-V, and Xen.
In regards to your question of whether or not DroboPro is fast enough to handle a dozen VHDs all running concurrently, it should work just fine, but it really depends on the workload.
Hope that helps clarify things.
Over a gigabit ethernet connection, you're only going to get a maximum of 120MB/sec. And that's best-case, you'll probably top out at 100, and that's even if the Drobo can keep up with that (though I've heard it can).
I've used iSCSI from an EMC Celerra over the same transport - it did relatively well for 10 or so low-usage hosts, 1 SQL server doing maybe 250-500tps and a Clearcase server doing probably triple that.
Personally until there's more information out there on the Drobo Pro's I would avoid them. The regular Drobo is not enterprise grade equipment and has lackluster performance. I would have to be convinced that the Pro is up to enterprise grade before deploying it in a production environment.
I know a while back on the Xen mailing list there was at least one thread with a user trying to use a Drobo Pro for the storage for Xen Virtual Machines. And they were running into IO errors with it. So you may or may not run into the same or similar issues with Hyper-V. So be prepared to do some testing.
I bought a 4TB Drobo Pro to run hyper-v for some of my development boxes. I'm using the iSCSI interface, and carved the drives up into 3 1GB partitions. I get good performance copying to and from the drobo, but as others had said the hyper-v performance is quite bad if you have a heavy IO load. I've been able to make it usable by moving some of the .vhd files to the different partitions.
Just to add my 2c to an already well answered question, if you are looking at storage for VMs it's a really good idea to think about each VM as an individual, with it's own storage needs, rather than being just part of a clump of VMs. For this reason, it may be fine to consolidate your VM system boot files on one volume of SATA drives, but if you're after performance and running a SQL database then it's best to have separate heads for data, logs, temp and so on. Similar scenarios would apply to media streaming, backup servers, anything were there are sizeable amounts of IO.
I've not used Drobo, but I appreciate they offer a simple solution to SMBs and to those developers who are hardware/sysadmin averse (i.e. most developers in my experience). There are so many good iSCSI solutions around at the moment, and standalone iSCSI target software is getting really good. If I were to build an iSCSI system now, I would probably look on ebay for a mid-range DAS shelf with about 12 SAS disks and couple it with a rack server that has a good raid card (or two) and is running an iSCSI target (Windows Storage Server 2008 r2 would be perfect in your case). It won't be as pretty as a Drobo (or nearly as quiet), but it will be flexible, adaptable and if you configure it well, you'll get better performance.
I can second Michael's statement that the DroboPro works well with Windows hosts and am seeing the good file copy numbers he is seeing.
The bad news is that we are trying to use the DroboPro to house VMWare ESXi 3.5 datastores and are seeing poor performance in that use case. We've configured the DroboPro per the VMWare best practices whitepaper, have it filled with 8x750 Gb 32 meg cache 7200 rpm Samsung drives with double parity on the storage and are getting substandard VMWare performance. We haven't been able to get much more than 10 MB/second despite the direct connect 1Gbps full duplex network connecting the DroboPro to our Dell PowerEdge 2900 ESXi server.
After 10 days of troubleshooting with support the answer we were given was "In regards to the performance issue, this will require a firmware update on DroboPro. This is currently being worked on and we hope to release jan/feb. time frame."
