Esx 4.1 and Fusionio 160GB SSD

[jonhutchings]

Hi,

Has anyone done any testing of different VMFS blocksizes and the effects on performance when using the fusionio SSD card in an ESX server. We've just got a coupe of these cards to experiment in host some specific VM's that need maximum performance from disc.  Reading the dosc for the drivers, they suggest creating VMFS with 4MB blocks, which on a 160GB SSD seemed odd, so I was wondering if having a larger block size helps with SSDs or perhaps prolongs life of the device through fewer larger writes ?

Anyone got any experience of these devices?

Thanks

Jon

[mcowger]

Theres no real performance difference for the various blog sizes, and all guest writes are passed through to the underlying device, so the 4MB block size doesn't really matter.

My guess is that they suggest 4MB as a standard for their cards because their largest card is 640GB and a 4MB bock size would allow one to create maximum sized VMDK on a cad of that size (1TB would be the limit for a 4MB block size).