Dirk Paessler's questions

VMware and many network evangelists try to tell you that sophisticated (=expensive) fiber SANs are the "only" storage option for VMware ESX and ESXi servers. Well, yes, of course. Using a SAN is fast, reliable and makes vMotion possible. Great. But: Can all ESX/ESXi users really afford SANs?

My theory is that less than 20% of all VMware ESX installations on this planet actually use fiber or iSCS SANs. Most of these installation will be in larger companies who can afford this. I would predict that most VMware installations use "attached storage" (vmdks are stored on disks inside the server). Most of them run in SMEs and there are so many of them!

We run two ESX 3.5 servers with attached storage and two ESX 4 servers with an iSCS san. And the "real live difference" between both is barely notable :-)

Do you know of any official statistics for this question? What do you use as your storage medium?

What options do I have to monitor a SAN server that provides iSCSI storage to a network for availability and performance? (Windows options preferred)

We are in the process of setting up two virtualization servers (DELL R710, Dual Quadcore Xeon CPUs at 2.3 Ghz, 48 GB RAM) for VMware VSphere with storage on a SAN (DELL Powervault MD3000i, 10x 500 GB SAS drives, RAID 5) which will be attached via iSCSI on a Gbit Ethernet Switch (DELL Powerconnect 5424, they call it "iSCSI-optimized").

Can anyone give an estimate how much faster a fiber channel based solution would be (or better "feel")? I don't mean the nominal speed advantage, I mean how much faster will virtual machines effectively work?

Are we talking twice the speed, five times, 10 times faster? Does it justify the price?

PS: We are not talking about heavily used database servers or exchange servers. Most of the virtualized servers run below 3-5% average CPU load.