Listen to your storage people.

We are also moving to VI3 using Netapp/NAS. So far performance is not an issue and our NAS is currently even faster than our SAN.

It's still too early to fully understand all the NFS benefits, but we see some MAJOR benefits by running VI3 over NFS and NO issues so far!

Here are some of the Netapp NFS benefits as we see it:

1. Snapshots! Snapshots! Snapshots!
Keep X daily and Y weekly snapshots of all your VMs!!!
5 minute restores of a VM or SnapRestore a WHOLE NFS volume if required.

2. Replication
Snapmirror critical VMs to a DR site and keep multiple snapshots remotely.

3. Capacity on demand
Netapp can grow and shrink NFS volumes dynamically.
No wasted space.

4. ESX Level Backups
Backup VMs at the EST level using Netapp NDMP directly to tape/vtl
NDMP will take a Netapp snapshot by default...
You may still need a guest backup solution for file level backups.

5. COST
NO SAN Switches
NO SAN HBA's
NO SAN Fiber Cables
NO SAN Drivers
NO SAN ZONING
NO SLEEPY SAN GUYS

6. Performance
Highly dependant on your Storage guys…

Highly dependant on your VMs needs.
Netapps support 10Gbit if more bandwidth is needed.

7. Other NAS Benefits
- Ability to create multiple NAS volumes on Multiple NAS appliances and VMotion to any NAS volume.
- You can use other NAS solutions (SUN 4U 4500s 25TB!) for staging VMs
- CIFS/NFS copy VMs to/from your ESX NAS storage.
- Snapshots (how did you sleep without them  )

Agreed... However, it's real easy to create a "NFS" only network back to your NAS device(s)... Just dedicate 1-2 gig ports on your ESX server(s) and plug them all into a isolated switch... Virtual SAN!

dp

We have just purchased a FAS3020 which we are going to run our VM's on but we already have a FC backend in place from the old SAN. We are going to use the FC fabric at our main site as we have not really tested iSCSI or NFS.

But at the same time i have bought a little FAS270 which i am now really considering using NFS over FC.

Guess i have lots of testing on my hands.

Well, especially with netapp you have more options than just NFS...

- why dont you use FC with the netapps?

Well, just 5 meters and one wall away there is exactly such a system, but i dont have the time to setup and run proper benchmarks right now.

Actually, what i MIGHT be able to do in the next weeks is a test with esx3 and then nfs vs. iscsi. But i dont have any spare fc-hbas...

If someone can provide them.... *hinthint*

It seems there are many conflicting opinions here, so let's get down to the facts (disregarding the cost for now):

FC is superior in terms of performance, scalability, redundancy and stability. The real benefit is that the fibre carries only SCSI commands and delivers a rock-solid sustained throughput, something not possible on Ethernet.

iSCSI is more like a disruptive technology, as it comes in between. The idea of encapsulating those SCSI commands into TCP/IP packets is brilliant, as your connectivity options expand dramatically. However, in order to get decent performance you need TOEs to get rid of the TCP/IP overhead that will crush your CPUs. So the cost can go quite high too without escaping the Ethernet arena.

NFS/CIFS and the lot are probably the easiest option, but also the most confusing. Performance is not optimal as you're subject to network traffic and you have many potential failure points on a rather meandering path. On 10Gb Ethernet things are certainly much better, but it's still early to adopt it.

You can mix the different technologies in order to exploit each one's benefits, depending on your needs and applications. But when it comes down to relying on solid performance for ESX, FC is (still) the clear winner.

My approach generally is something like this:

ONLINE storage (FC SCSI) for mission critical data
NEAR-LINE storage (FC SATA or NAS processor with SATA arrays) for file shares and non-critical data
OFFLINE storage (FC TAPE library and additional disk storage for virtual backups)

Running clusters of DB servers on ESXs that boot off VMFS and have direct access to the FC SAN for data/logs, has been my solution of choice.

One thing that hasn't been mentioned, that you do LOSE with non-FC storage is the consolidated backup feature of VI-3. VCB requires FC SAN...just wanted to mention since you asked about lost functionality...