Upgrade to Home Lab – Synology DS1812+ with SSD Cache
A small but effective upgrade to my home lab; originally I was running my two ESXi hosts on local storage. Each Dell PowerEdge R610 host has 2 x 300GB SAS 10K disks in RAID 0.
Obviously I wanted to move to something that provided some redundancy as soon as possible, but performance and capacity was also becoming a factor. My lab currently consists of about 10 VMS; domain controllers, file shares, vCenter server, Exchange server, monitoring, backup server. Performance has begun to get a little sluggish, and by all accounts the bottleneck appeared to be the disk IO. With plans to add another Exchange server shortly, things were only going to get worse.
So I’ve added a Synology DS1812+ NAS, loaded with 7 x 3TB 10K disks and a 120GB SSD, in the hope that the additional spindles and SSD cache will improve things, despite the additional Ethernet journey data will have to take.
I’ve put 6 of those disks into a RAID 10 configuration, a single volume of 8.17TB that I’ve initially split into an iSCSI LUN for a shared vSphere datastore, and a network share as a Veeam backup repository. The remaining disk is a standalone volume used as a secondary backup location for my Lab. This is temporary, as obviously a properly redundant backup would be to a completely separate device. I’ve put enough hours into this lab that I really really don’t want to have to start my lab from scratch again!
The SSD drive is used as a read-only SSD Cache on the iSCSI LUN. I may add a 2nd SSD in RAID 1 to enable read-write cache (having the SSDs in a redundant RAID configuration is a prerequisite to caching write operations), but I’m unsure if this would provide much in the way of a performance boost.
Initial impressions are a decent improvement in VM performance in my lab; OS operations are certainly snappier, although RDP/VMware Console can feel a bit laggy at times. Obviously the redundancy provided is a huge bonus, and the shared storage will allow me to lab some vCenter features I couldn’t previously try with the local datastores.
From a network and topology point of view, the Synology NAS (MIDNAS01) has two bonded LAN uplinks, connecting separately to two access switches to provide redundancy, onto a storage VLAN. Each ESXi host has a single dedicated physical NIC for connectivity to this VLAN. Updated lab network diagram below.