This is Part 3 of a series of blog posts on building a Home NAS & Server using Linux. For the full index and other details, please see the Index
Once the software choices had been settled on, it’s easier to get a clearer picture on what I want to get from the hardware along with quite what spec I need.
Having initially wanted to make the new case fit into a 3U max space (which is what I happen to have free in my cabinet at the moment) I was getting a bit nervous when trying to find options. What I began to find was that the vast majority of the available options will easily fit in 2U or 3U, but most end up requiring 26″ depth, which I don’t have. The smaller cases were largely ruled out as they required boards that couldn’t take the amount of RAM I’d want, or didn’t have the requisite disk / expansion slots to cater for the storage side of things.
For a long time I was looking at the Antec rackmount cases (2U/3UEPS systems) but found them hard to source and I was concerned about getting tied in to specific (expensive to replace) PSUs. As time’s gone on it seems they’re hard to find because they’re being wound back, if my recent visit to the Antec website is anything to go on. I later shifted to looking at the Chenbro RM-22300 because it’s seriously cheap, and meets the form-factor requirements. As an additional bonus it also fits standard PSUs, although it looks a bit of a cludge in how its cabled. It’s big drawback is that whilst it would fit the bill today, it lacks room for any real expansion.
Looking back at things more recently, I’ve figured I can safely sacrifice my 2U shelf in order to make room for a 4U case. Whilst I don’t need anything that size right now, it pretty much allows for a full-sized desktop case which means normal PSU, lots of drive bays, and plenty of easy-to-facilitate expansion. Provided I get some fixed rails to support the weight, there’s no real reason not to look at it.
As I liked the look (and reputation) of them already, I went back to the Antec 4U22EPS650 option which comes with a PSU and has plenty of room and options. One nice point is it can potentially be expanded to have 3×5.25″ slots available on both sides of the rack, allowing for hot-swap bays to be added fairly painlessly. It’s easier to find than the other options and will easily address any future expansion concerns.
Hot Swap Drive Bays
Whilst not exactly a key requirement to be in place on the new build from the get-go, easily accessible drive bays is something I’d definitely like to have in place.
I’ve been looking at a few possibilities, but the one that still leads at the minute is on of the 4.35″ in 3×5.25″ options from IcyDock. Not being in a position to get one yet, I haven’t quite decided whether I want to go fully tool-less or not, but price will probably be the main deciding factor. Otherwise, they’ll all do SATA3 which is my only real concern.
As I’ve already covered, one thing I am keen for this box to do is cater for other projects beyond the scope of a “standard” NAS, including acting as a hypervisor and a PVR backend. So it could do with a bit of oomph in the CPU department, whilst at the same time being conscious of the fact it will be on most (if not all) hours of the day. Given that I’ll be using ZFS for my storage, it also needs to be (ideally) able to work with ECC memory. The more I looked at available desktop options, the more I came to realize that using one of the newer i3 / i5 / i7 Intel chips would mean sacrificing ECC or paying a lot more for enterprise boards – which I can’t justify at the minute. ASUS, on the other hand, offer consumer boards that support ECC merrily in their AMD line.
So I got looking to AMD CPUs. Looking at the stats, the energy efficient ones have considerable savings, but were hard to find in the UK. Not impossible though, and I managed to pick up a 615e on import. I just needed a Heatsink / Fan for it, which eBuyer helped with.
Having already come down on the side of an AMD CPU and ECC RAM, I was looking fairly firmly at Asus to help fulfil the motherboard requirement, and I don’t think they’ve disappointed. The M5A99X EVO ticks all the right boxes and caters for a good number of hard drives (6 using SATA 6Gb/s ports and 2 using 3Gb/s) along with ECC RAM support.
As with the CPU decision, power usage here won’t be as low as I might have wanted from a “pure NAS” box, but it will should have more than enough grunt for the additional tasks I want it to perform.
The MB can take up to 32GB ECC RAM, but I found 8GB ECC Unbuffered DIMMs hard to come by. All the main manufacturers’ sites have them, but finding them at suppliers was more of a challenge.
In the meantime then, I’ve opted to settle on 4x4GB DDR3 PC3-10600DIMMs from Kingston, KVR1333D3E9S/4G. The pricepoint is pretty good for my plans, and 16GB should give me plenty to work with.
Longer term, 32GB is the plan, using 4 8GB DIMMs, but I can expand to that when needed.
At the same time as I first started thinking about doing this build, Western Digitial released their Red drives, aimed specifically at the SOHO NAS market. I’ll be honest, I don’t know a vast amount about the intricacies of hard drive technology – and I do appreciate that “Enterprise” / “Server” drives will always be more substantially tested than SOHO / Desktop equivalents – but in the reading I did around these, the implication seems to be that they’re worth a go. Firmware improvements, longer-than-normal warranty and being pitched (and tested) as always-on seems to make them a reasonable choice. I guess time will tell.
When I first set about this, I sort of default assumed I’d be looking at the 2TB drives as a price compromise between safety and resilience, either in a mirror or raidz (RAID-5, effectively) configuration – so tolerable of 1 disk failure. However, recent discussions haveencouraged me to look towards using the 3TB disks, but upping to raidz2 (double parity).
For the boot disk, I’ve opted to go with a single 2.5″ SATA2 drive from WD. I might eventually up this to a software mirrored RAID option, but as all the important details will be backed up to the ZPool anyway, downtime for a single disk failure isn’t the end of the world (at this point).
Side Note: The Other Build
As noted in passing earlier, I am also building a similar (but slightly lower spec / requirements) machine for my parents. The intention is this will serve both as a central store and backup machine along with serving as an off-site backup for myself using snapshot send / receive.
This machine wouldn’t need to do the extra stuff I want the rackmount box to do. It doesn’t need to PVR and it doesn’t really need to host VMs. It needs to hold data and run some relatively light services for the rest of the network.
Given the £100 cashback offer that HP are still running, I opted for a HP ProLiant N40L Microserver, replacing the 2GB RAM with 2 x 4GB ECC RAM modules and adding a StarTech PCI-E Dual-Port Network Card to add the additional ports the box will ultimately need. For disks, I used three Western Digital Reds, 2TB each, and kept the 250Gb that came installed in the system as a root drive.