Ever since discovering the joys of networked streaming audio delivery around the house I’ve had a need for a centralised location to store our music (currently around 560GB of lossless FLAC files).
As is often the case with these things, old bits of hardware are re-purposed to do the job, being replaced when they become too slow or break.
The current server was never built for power efficiency and the drives are fast, power hungry devices. A recent check of the SMART stats of the drives shows that 3 of the four drives have continuous power on hours of almost 4 years and are out of warranty – time for a new build with some greener credentials.
The current server is around 4 years old and based on a dual-core Pentium mobile based industrial motherboard, with a single boot disk and a RAID5 disk array for our main storage, all built into an old case I had kicking around. It runs Mandriva 2010 with the RAID array being managed by the Linux software raid tool MDADM with Logical Volume Management (LVM) for flexibility in storage allocation.
LVM has been a real bonus as it allowed re-sizing of partitions to suit the size of the data being stored. Whilst this is better than not having this ability it’s still a manual process to re size a partition and a nerve wracking one (although it should be noted I’ve never lost data as a result of these changes, a testament to the maturity of Linux and it’s tools).
The RAID array originally consisted of 3x 750GB drives, giving around 1.5TB of usable storage, with redundancy in the event of a single drive failure. Another 750GB drive was added a year or so later, bringing total storage up to ~2TB. In the four years it’s been running I’ve had one drive failure after 2 years (replaced under warranty) and more recently another drive failure, which I haven’t replaced yet so the array is now running without redundancy and at risk of total failure. Fortunately I keep regular current backups so this state of affairs is acceptable for a short period of time.
The server’s usefulness has also grown over the years, changing from a simple file server for music, to one that stores video (which grew from SD to HD), digital photos, files and ultimately into a virtualisation platform (using KVM) to run several virtual machines (Vortexbox for media distribution, several Minecraft servers etc.).
As one can’t really put a price on irreplaceable personal data I decided to finally invest in some cold hard cash in some decent hardware.
I looked at NAS solutions but all the consumer grade products have limited functionality given my existing useage pattern. They are also surprisingly pricey, I’m aiming for 4-6TB of redundant storage and NAS boxes that are capable of this are expensive and less capable than a PC based solution. I’m also a geek that loves learning new stuff, so building my own custom solution and gaining knowledge along the way appeals to me.
My initial thoughts therefore were towards the excellent HP Microserver range. With £100 cashback available they can be bought for just £150.
These compact. power efficient and incredibly well-built boxes have similar CPU horsepower to the existing server, using an AMD Turion II N40L CPU. The increasing use of virtualisation though lead me to think a bit more CPU grunt might be useful.
The trade off here is usually between power consumption and speed; a quick look at the E3-1220 Xeon based ML110 G7 servers left me thinking both idle peak power consumption was a bit high for my liking, and also the server was much pricier at around £400.
I then stumbled across the HP ML110 G7 G840 mini tower server, this is only £20 more expensive than the Microserver, but also has a £100 cashback, bringing total cost to £168. The CPU, whilst only dual core single threaded, had a lot more grunt that the Turion, idle power consumption is only slightly more than the Turion and peak power was sensible.
You can get a good guide to HP server power consumption as HP has made a great tool called HP Power Advisor to allow you to virtually configure any of their servers (adding drives / memory etc.) and get a good estimate of idle and peak power useage. Obviously there will be differences as the online calculator only uses HP products, with some low power green hard drives this should make a good performing, but greener, solution.
The ML110 is lovely bit of kit, with some advanced features. It’s well build, heavy and solid, has easily accessible front drive bays and is very quiet. Even with it’s three fans it makes little more than a whisper. As a product aimed at (low end) enterprise it has built in HP Integrated Lights Out (iLO3) capability.
This means that providing the server has a power and ethernet connection you can manage it. Even powered down access is available via ssh terminal or a nice Web UI, allowing remote power up / down, sensor monitoring (there’s a sea of sensors on this thing!) and even remote console access, allowing you to see the video output even during boot. this latter feature does seem to need an (expensive for home use) licence for continued use.
Hard drive pricing is all over the place still at present, after the flooding in Thailand, but prices are coming back down to sensible levels. Warranty lengths have dropped though, from 3-5 years down to 2 in many cases. I opted for 4x 2TB WD20EARX green drives with a peak power consumption of just over 5W / disk and idle powers of <1W. These disks use the new advanced format (AF) 4096 sector size which needs to be taken into account when using them to ensure performance does not suffer, these technical details will be covered in a later article.
That pretty much covers the hardware, for a total cost of around £400 (~£170 for server ~£240 for hard drives) I have a very powerful, efficient and solid hardware base to build on.
In the next installment I’ll discuss software and OS choices for the new build, including the awesome be-all and end-all of filesytems, ZFS.