I built up my home lab back in late 2011 after finally deciding that I needed something that was completely mine and not a shared lab with others. I built pretty much an identical lab to Jase McCarty’s (http://www.jasemccarty.com/blog/?p=1516) and have been very happy with it. The only problem I’ve had is with my home lab storage.
A funny thing happened on the way to figuring out what storage to use in my home lab. Faced with the prospect of using a home NAS with 4 SATA drives, I wanted to see if I could find something that would give me better performance. I had the opportunity to get my hands on a server that had 6 x 146GB 10K RPM drives and I jumped at the chance. That server ended up being an old DL380 G4 (possibly even G3, not sure). It seemed so smart at the time – why use 7200 RPM consumer SATA drives when I could use 10K RPM enterprise SCSI drives and get better performance. I didn’t factor in one important thing: cache, or lack thereof.
After seeing miserable performance I researched and bought some battery backed write cache – a whopping 128MB worth that had to be split between reads and writes. Even with that, and using iSCSI software that let me create a RAM cache, I still had pretty bad performance. How bad? This bad.
Yep, that’s over 4,000ms of latency. It wasn’t consistently this bad but trying to do multiple operations at once, like rebooting two VMs at once, would cause it. The server was old, not true 64-bit, and just not the right fit. There were probably other contributing factors beyond the lack of cache as well. Not to mention the electricity cost of running a true server class computer in my house. I realized my mistake and knew I needed to replace it with dedicated NAS storage.
I know I could have used something like Nexenta Community Edition to get better performance out of the DL380. For a variety of reasons that didn’t make sense in this situation.
After much research and quite a bit of unnecessary delaying on my part (with the appropriate amount of ribbing from @ChrisWahl and @Millardjk) I finally decided on the Synology DS1812+. I loaded it up with 4 x Sandisk 240GB SSD and 4 x Western Digital Red 2TB SATA drives and plan to use it for my home lab as well as for backing up my PC, pictures, videos, etc.
So how well does it work? Is it a worthy replacement to the DL380? Seriously, what isn’t a worthy replacement to that old server?
I have been extremely impressed with the Synology DSM software and how easy it is to set up volumes, create iSCSI targets, and configure link aggregation (more on that in a bit). It also has lots of great features to use it as a home NAS so I’m very happy with my choice. Performance has been great both on the SSDs and on the Western Digital Red drives. The days of seconds of latency are gone – as you can see in the screenshots from esxtop I’m able to push extremely high I/O (both reads and writes) with less than 3ms of latency. I may do some more detailed testing with the I/O Analyzer fling but for now this is good enough for me.
My only disappointment is that I cannot configure true 802.3ad Dynamic Link Aggregation. Unfortunately the switch I use in my home lab, a Dell PowerConnect 2816, only supports static link aggregation and not dynamic. There are many posts on the Synology forum complaining about this but it’s really Dell’s issue and not anything wrong with the DS1812+. I consider that a “nice to have” for a home lab but certainly not worth investing hundreds of dollars in a new switch that supports the proper link aggregation configuration.
All in all I’m very happy with the addition of the Synology DS1812+ into my home lab. The performance is great, the DSM software is very good, and there are some great things coming in the new DSM 4.2 (currently in beta). I highly recommend any of the Synology models to folks who are looking to upgrade their home lab storage.