I bought a HP Microserver a little while ago to replace my 15 year oldish raid server. I will be going from a full tower (around 60cm tall), 2.7 TB, 8 drive raid 5 array with 3ware raid controller (with OS on separate HD of course) running Gentoo to a HP Microserver coming in at just 27 cms high, 4 TB on a single drive (for starters), with capacity for 3 other HDs (could have more if I use the 5.25 slot for more HDs...how things change.
Yesterday night I upgraded the paltry 2GB RAM it came with to 8GB RAM (system can handle 16 GB RAM apparently, might bump it up in future). The server is super easy to take apart and get to the motherboard. The HD bay is also really convenient to get to, so when the 4TB HD comes through, it should be a breeze.
I went for the Hitachi 4TB Deskstar (7K4000) in the end. It was the top 4TB recommendation in Toms Hardware tests back in April 2012 and is at a price point within my budget now for the performance. This arrives today to be installed tonight after the bios firmware upgrade and Amahi install.
There are actually a few modded bios firmwares available for the HP (see below link). The one I'm interested in is the one that allows the 6 USB ports to have AHCI enabled. As it will be a server, I like to update the bios to the latest before I install any software, OS or otherwise, so this will be the first thing I do. Luckily both the official and modded firmware are built to be done from a USB stick, so don't foresee any extra work there.
Once the firmware is updated I'm gonna be installing Amahi for all the NAS type things like sharing files, media, music and a whole host of other things.
Amahi recently changed their install process from "install OS yourself, then install Amahi" to "here is an ISO that you need to burn to DVD and do the installation". Currently that is the only supported method. I don't have a DVD reader (and don't intend to have one as I have very little use for one) so can't use that method. However, they have published a how-to for all us unsupported types, so hopefully will have the system up and running tonight. Then I can copy across the existing 1.8 TB worth of data, backup to Bitcasa, and decomm. my 15 year old server...tears will be shed.
Official Microserver Bios Firmware: http://h20565.www2.hp.com/portal/site/hpsc/public/psi/swdHome/?cc=us&lang=en&sp4ts.oid=4310887&ac.admitted=1378208218979.876444892.492883150
Modded Microserver Bios Firmware allowing 6 ports of AHCI SATA 3gb/s: http://www.avforums.com/forums/networking-nas/1521657-hp-n36l-n40l-n54l-microserver-updated-ahci-bios-support.html