What are the most important aspects to consider when choosing a SAN for a small office virtualization project?
I am in the process of consolidating 6 physical servers running 6 different operating system flavors (don't ask) into two identical physical servers (Dell PowerEdge 2900), using the free VMware ESXi 4.0 platform. We will install an iSCSI SAN over a 1GbE network, and store all virtual machine images on the SAN. Each physical server would run 3 VMs, and in the case of a physical server failure, we would manually switch over the other 3.
These are all internal servers, while important, they can tolerate some amount of downtime (say <1h) to keep cost and complexity associated with HA down.
I now need to choose the SAN to be used for the setup, on a low budget. We currently have about 2TB of data, but of course I want to able to grow, do backups of VM snapshots on other drives and remove them to a different location, etc. So what I would like to know is:
- Which are the must have features for this setup, without which using a SAN is not worth it?
- We are mostly a Dell shop, so I have been looking at the EqualLogic PS4000E High Availability model. Any opinions, anecdotes, bad experiences with this model? (This is one of the few models which could accomodate our existing disks from the physical servers.)
- If you can recommend something that is not Dell, but it has better value, I would most definitely consider it, but be sure it is included on the VMware Compatibility Guide.
- Caveats, things to look out for?
Update:
I have dropped the EqualLogic model due to the higher price and disk incompatibility. The MD3000i you guys recommended looks great, but I still want to consider other alternatives before deciding.
Can anyone comment on the Fujitsu ETERNUS DX line?
I am still waiting for a quote from our Dell representative for the MD3000i, but I have an idea from the web page for the ballpark. I also have some preliminary prices on the Fujitsu ETERNUS DX60, which suggest that even if I reuse disks in the Dell, the Fujitsu will cost less with the same config, buying new disks.
Decision:
We also took a look at the HP StorageWorks P4300 G3 and P2000 G3 lines. The P2000 G3 line has FibreChannel/iSCSI combo controllers, and is more expensive than the Dell and Fujitsu, even without any disk. The P4300 G3 line has iSCSI only models, but they force you to buy a system with all 16 disks, so it ends up too expensive as well.
We got very similar quotes of about 6K Euros for both the Dell and Fujitsu with 4 x 1TB Nearline SAS disk in RAID10. Since we Dell already supplied us various hardware and we have a good relationship with them, we chose the PowerVault MD3000i.
Many thanks to everyone for your input!
I'm no expert on equallogic, but Dell's md3000i might cover all your needs: 15 drives in the basic setup, and you can expand it with up to 2 (or maybe even 3, can't remember) MD1000 boxes, 15 drives in each.
The boxes are well supported on ESX or any other hypervisor you might choose
Small shop? Dont go hardware. BUy a decent server that ALSO does virtualization SAN.
You can easiyl get servers that can host a lot of discs. Good value is a Case from SUpermicro - 2 rack units, 24 disc slots. OTherwise get a significant (i.e. large) case with many 2.5" slows and put in SuperMicro 2.5.25" to 8x2.5" trays - 8 discs in 2 2.5" slots with SAS backplane.
Make the server decently powerfull. RUn on it what you want. Anyhow...
StarWind has a nice relatively low cost ISCSI target software for windows. Use it to expose ISCSI targets as needed. FOr high performance dump out and expose a compelte RAID set on the host.
I Think this gives you a lot better valuie for the money than buying a dedicated box.
If that is still too high a budget (btw., I run a setup like that - very happy with it), you can use a Thecus / QNAP etc. NAS / SAN combo. The QNAP SS839 looks really nice - as does the 859. put in fast discs WD Velociraptor) and it should be "good enough" in a positive sense. For a much better price. AND noise - actually given 2 decent servers and a QNAP - you can make without server room. Any rack equipment is NOISY.
In your planning make sure to take into account the cost to expand beyond the basic SAN unit. If the basic SAN unit holds 15 drives, how much does it cost to add the 16th? Can you add a cheaper disk tray/chassis, or in the case of the Equallogic do you have to buy an entire additional SAN unit?
If it is going to be a mixed use SAN, what is the performance needs of your use cases?
BTW, i've got a quote for an MD3000i with 4TB+ of SATA II 1TB drives (with sparing, RAID5) in the $7K range.
Before you commit to a SAN, look at getting a NetApp NAS (can use iSCSI or NFS). Deduplication technology, plug and play off-site hot/cold failover down the road.