SSD caching on PowerEdge 2950 6 drive RAID 10 array - possible?

[tankman1989]

I'm curious about a couple things. I have an 80GB SATA II SSD drive that is a little small for the application I intend but I think it could be an excellent cache drive for my 2950 as it is running a RAID 10 array.

I am running ESXi 5.5 and OS's like Server 2008 R2, various Linux flavors and some Windows guests.

Is there a way to use this SSD as a caching drive in this setup?

 

[NetJunkie]

With ESXi 5.5? Yes. You can do read-caching using vFRC (vSphere Flash Read Cache) that comes with the Enterprise feature seat. Or you can buy PernixData FVP for read and write caching. But nothing free.

 

[drescherjm]

How about passing through the drives to a zfs or recent linux guest and let the guest OS do the ssd caching and allow access to the other guests using iscsi

 

[diehard]

With ESXi 5.5? Yes. You can do read-caching using vFRC (vSphere Flash Read Cache) that comes with the Enterprise feature seat. Or you can buy PernixData FVP for read and write caching. But nothing free.

Flash Read Cache requires Enterprise Plus, fyi

 

[tankman1989]

Thanks you for the suggestions. I would like to avoid using products I have to purchase ATM because this is for home use/testing. How does this sound as a possible solution or at least a way to utilize the SSD across all machines in ESXi.

Create a datastore on the SSD and on that create a "virtual drive on each to house the pagefile or swap partition. If my understanding is correct, those two are most frequesntly accessed and act as a "middle-man" between disk and RAM (after it has been read from Disk the first time).

Will that create a benefit at all?

 

[diehard]

You wouldn't need to make a datastore, ESXi can use flash memory for VM pagefile's starting with 5.0, however it will only benefit if you have RAM issues.. i believe.

 

[tankman1989]

You wouldn't need to make a datastore, ESXi can use flash memory for VM pagefile's starting with 5.0, however it will only benefit if you have RAM issues.. i believe.

No RAM issues yet, so are you saying that the pagefile and swap files aren't really used unless I run out of space in RAM?

 

[diehard]

No RAM issues yet, so are you saying that the pagefile and swap files aren't really used unless I run out of space in RAM?

Basically..

You can configure ESXi to use a portion of an SSD-backed datastore as swap memory shared by all VMs. This is only useful if you plan to heavily overcommit the RAM of your host (e.g. in VDI scenarios). Swapping out a VM's memory to disk is the last resort if all other memory reclamation methods (like page sharing and memory compression) have already been fully utilized, and it will usually have a significant performance impact. However, swapping to SSD is less bad than swapping to hard disks and will reduce this impact.

vFRC would absolutely help but again, you need enterprise plus.