ESXi Ent Plus - SSD Cache

[COS]

I've been doing some reading on this. I read a lot about it's "Read Cache" but really nothing about write cache.

VMware KB: Virtual Flash feature in vSphere 5.5

Does the "Cache" feature on SSD's have the ability to cache "Writes"? If so, how do you configure it?

Thanks

[vervoortjurgen]

i think its enabled automatically

• Increased storage write speeds due to a reduction in common storage read operations.

[a_p_]

I doubt that you can use the SSD as write cache. Doing write caching on the local SSD would most likely result in data corruption on  the shared storage in case the host unexpectedly fails, i.e. cannot flush the cache to the VM's virtual disk before going down.

André

[COS]

Yeah, I thought about that too but I was still curious.

Thanks everyone!

BTW, where did the points go?!?!?!?!?

[VRBitman]

The technology does not do anything for write operations, it only accelerates reads. Hence the name.

[COS]

Yeah, I gathered that. It's kind of a waste of SSD's to only use half of the best features of expensive SSD's.

I think I will take a look at the SanDisk product as seen from VMworld. Seems promising.

[VRBitman]

An interesting alternative to vSphere Flash Read Cache that you might consider is PernixData FVP. FVP accelerates both reads and writes using flash-based devices.