Not really a SharePoint specific issue, but something I wanted to share with the community.
Probably like me, many people out there might be running a hyper-v or esx based lab env at home that is used to spin up new version of software for evaluation or to try something out when an idea comes to mind.
Given that most half decent PC’s these days can handle upto 32GB of Ram, this gives plenty of scope to run quite a few virtual machines, however relying on cheap SATA disk’s to run the VM’s on can become a bit of a problem once you have more than a couple of VM’s running at once, especially with SharePoint 2013, when you might want a Domain Controller, SQL server, SharePoint Server, plus an OWA server.
I’d like to tell you about a piece of software I came across the other day that makes a big difference.
I have 4x250GB 7200rpm (RE4) SATA drives in RAID 1 (On intel ICH7R) in my lab server with 16GB of Ram, giving approx 500GB of storage for VM’s, I tend to set them up with a base image for each O/S and a differencing disk for each VM to get the most out of my underlying storage in terms of numbers of VM’s, once more than a couple of VM’s were up and running doing stuff the array would thrash around and the responsiveness of the VM’s would get slower and slower, once 3 or 4 were active it was getting to the point were things were taking a long time to respond.
A pure SSD drive setup giving the same storage volume as I would like is still upwards of £500-£800, so switching to pure SSD setup isn’t justifiable for a home lab, so I brought 2x32GB SAN Disk SSD’s (The Ready Cache Branded Ones) hooked them up to my LSI 8888ELP raid controller and setup them up in Raid 0, this is to spread the write load across more than one SSD (worried about NAND cell fatigue as these drives are MLC) from the 64GB virtual drive I created two 32GB logical Drives, allocating one of them to use a cache volume, the other as a high speed temp storage area, then I used some software from a company called velobit, specifically there hyper cache product, that can cache storage volumes using a bit of RAM and SSD drive’s, to say the results were impressive is an understatement.
Suddently VM’s that would take an age to respond, now spring into life, whereas before a run of crystal disk mark in the VM would stuggle to get more than 30-40Mbytes a sec on linear transfer, with random I/O that was in the 100’sKbytes/s range, now liner I/O in the VM’s is upwards of 250Mbytes/s and even random I/O is up in the 50-80Mbyte/s range, a marked improvement. I can now run 6 or 7 VM’s at once without problems, RAM is now the issue 🙂
Given that the software is free for home use, although it does restrict the size of the SSD cache down to 32GB (Pro version is paid for and unlimited), I would say in terms of Bang for Buck nothing comes close, if you have an SSD or two lying around that is to small to do anything useful this is a great use for it, your VM’s will perform much better without the need to go full SSD for the storage.
I have no involvement with velobit, just think it’s a great product that can make your home lab much more productive.
Have a look you won’t be disappointed with the results.
Update on this subject, seems some of the big storage vendors also think the same way, just got an e-mail saying Velobit have just been acquired by HGST, so I’m not sure if that may change the availability of the free version of the software, will keep an eye out and update this accordingly.
Update 2 : Seems velobit are no longer offering there caching software any more, looks like it will be engineered into an offering from HGST in future, not sure if you will be able to use it at home for free once that is complete. They are allowing people who already have the software installed to continue to use it, but not offering it for download any more, such a shame as the freemium version is very useful for a home hyper-v Lab.