Thursday, August 4, 2016

A Cost-Effective DIY LOCKSS Box

Several LOCKSS Alliance members have asked us about cost-effective, high-capacity LOCKSS box hardware. We recently assembled and are testing our answer to these questions, a LOCKSS box built into the U-NAS NSC800 chassis. It supports 8 3.5" drives so, for example, using the recently available 8TB drives and RAID-6 it would provide about 48TB of raw storage before file system overhead. Below the fold, a detailed parts list, links to build instructions, and comments on the build process.

Here is the parts list for the box we built, without the 3.5" disks, using one-off retail pricing.
Chassis$199.99U-NAS NSC800
Power Supply$119.99ASPOWER U1A-C20400-D
Motherboard$113.99Gigabyte GA-H170N-WIFI
Memory$59.99Crucial CT2K8G4DFD8213
CPU$59.14Pentium G4400 BX80662G4400
Fan$39.88Noctua NH-L9I
O/S disk$84.29WD WDBMYH3200ANC-NRSN
RAID Controller$239.89LSI 9211-8i
Once you have all these parts, you need to assemble the system, which took me 4-5 hours. The official NSC800 installation instructions are completely pictorial and generally very good. The one part they don't cover is plugging the cables into the motherboard because, of course, exactly where they go is specific to an individual motherboard. So you will also need the installation instructions for your particular motherboard, which in our case are here. Anandtech has a report on building a NAS system using this chassis.

It is important to note that the fan that comes in the Intel package is slightly too high to fit, so a low-profile fan such as the Noctua NH-L9I must be used instead.  Finding an even lower-profile fan than the Noctua's 14mm would make the assembly easier.

The only tricky part of the process is getting the motherboard into the case. There is very little room, there are a lot of cables to be kept out of the way, and there is an insulating sheet that must be installed between the back of the motherboard and the case. Our advice is:
  • Make sure everything is working by bringing up the system before installing the motherboard in the case.
  • Insert the top of the motherboard into the case.
  • Hold the cables out of the way.
  • Push the motherboard up to get the bottom of it into the case.
  • Push it towards the rear to align the connectors with the holes in the fascia panel.
  • Slide the insulating sheet into place.
  • Insert the screws starting with the top front one.
  • Boot the system to check that you haven't detached any connectors before continuing.
Two points are important:
  • The motherboard we used is overkill; it has many features a LOCKSS box doesn't need.
  • Ideally, the system disk would be a pair of drives in RAID-1 so that a drive failure would not bring the box down. In our case we didn't think it worth doing.
Here is our suggested parts list using 6TB drives, a cheaper motherboard and dual system disks. We haven't much experience yet with 6TB drives, but Backblaze reports good experience with Seagate ST6000D000 drives. These are no longer readily available, so the list uses the current Seagate NAS 6TB drive, the ST6000VN0012 at $239.99.

Using RAID-6, the parts provide about 36TB of raw storage for about $2.9K exclusive of shipping and tax, or about $80/TB:
Chassis$199.99U-NAS NSC800
Power Supply$119.99ASPOWER U1A-C20400-D
Motherboard$67.99ASRock H110M-ITX/ac
Memory$59.99Crucial CT2K8G4DFD8213
CPU$59.14Pentium G4400 BX80662G4400
Fan$39.88Noctua NH-L9I
2 O/S disk$168.58WD WDBMYH3200ANC-NRSN
RAID Controller$239.89LSI 9211-8i
8 storage disks$1919.92Seagate ST6000VN021
The market lifetime of specific disk drive models is typically too short for customers to have much experience to go on when buying, especially with a new technology generation. Backblaze reports positive initial experience with Seagate's ST8000DM002 8TB drives at $298.

Using instead Seagate ST8000AS0002 8TB archive drives at $259.99 each provides about 48TB of raw storage at $3035.37 exclusive of tax and shipping, or about $64/TB. These are not the drives Backblaze is using. They use a fairly new technology, shingled magnetic recording (SMR), and are specifically designed for archival use. They should work well for LOCKSS. We don't yet have any experience to go on, but these are the drives we're using in the box we built, so we'll get some soon.

1 comment:

David. said...

My bad - I left out two important details.

1) For some reason the RAID controller takes a very long time to initialize itself and the drives during power-up. Do not get impatient, just wait.

2) After the first time you patiently wait, you will need to disable boot support on the RAID controller by CTRL-C to get into the setup utility, then selecting the adapter and ENTER to get its properties.