The main logistical problem with astrophotography is where to store all those precious hard won data files.
It's cheap to buy hard disks of quite large capacities nowadays. Indeed 12TB drives are easily available and can be utilized.
However there is an issue with magnetic harddisks and to a lesser extent SSD drives. If the electronics in the drive die then you stand to lose all your data. So why not copy your data to two or more drives as a backup. Yes you can do that and it works very well.
There is another option - use a NAS. Network Attached Storage. This usually comprises a box of disks connected to your local area network and that can be configured to store the data on multiple drives which are mirrored. Two drives mirrored are known as RAID1.
In RAID1 configuration if one drive fails then the other carries on. You purchase a replacement drive for the one that has failed and restripe it once it is put back into the box.
There are many other forms of resilient storage methods RAID5 RAID10 etc which I won't go into here.
You can purchase off the shelf NAS boxes that are plug and play ready to go indeed I have a couple of them already. However this time I went down the route of building my own.
First of all an enclosure was sourced. This was the very fine Silverstone DS380B 8 Bay NAS Chassis which has a small form factor and supports 12 internal drives. 8 of those drives are hot-swappable meaning that you don't have to power down the NAS when extracting the drives. So when one drive fails, you purchase a replacement, remove the failed drive and then insert its replacement. No down time.
Door open showing drive bays
Side panel removed
The enclosure also has magnetically attached dust filters. One large one at the side of the drive bays and a smaller one that covers the inlet to the power supply. This is a really good idea as it prevents dust from accumulating inside the NAS.
However the NAS chassis does not come with a power supply so you have to buy one separately. I bought the Silverstone SST-ST45SF 450W Power Supply. Silverstone also make modular power supplies without any cables so you can buy a cable set of short cables to aid routing within the box. The one I bought already had its cables attached.
Next a suitable systemboard was sourced. I found one made by SuperMicro which has support for 12 drives on board. This one was Supermicro Integrated Intel Atom CPU A2SDi-8C-HLN4F Mini ITX Motherboard. The Atom processor is not a particularly fast CPU but more than ideal for a NAS. It has 8 cores and uses 8 threads and supports DDR4 RAM. It runs at 2.2 GHz
The systemboard has an integrated IPMI network socket which among many things allows you to switch the server on remotely and also view what would be on the monitor screen.
It is akin to an ILO on a Hewlett Packard server or a DRAC card on a Dell server.
It has 4 x 1GB network ports which can be configured in a number of ways to suit your network such as Link Aggregation, Bridging etc. However you do need to have a suitable network switch to make use of those features.
Also it has a number of USB sockets, 2 x USB2 and 2 x USB3 on board so room for periperhals. It also has a VGA socket and one PCI socket for expansion cards.
It has capacity for 4 DIMM memory modules with a total capacity of 256GB RAM. I opted to buy 2 x 16GB DIMMS for a memory of 32GB. That is more than adequate for a NAS.
I bought 4 x Seagate 8TB NAS drives for the NAS. I already had a couple of 500GB drives that will be used as the system dataset pool and I had a 1TB SSD drive lying around to be used as the boot drive.
For an OS I chose TrueNAS Core 12 - formally known as FreeNAS - from iX Systems truenas.com as it is free open source code and supports up to 50 drives. There are other version of TrueNas, Enterprise and Scale which you are also free to try out and use again with the limitation of 50 drives. The latter two versions are more suited for large scale applications or industrial production usage.
The build came first and simply comprised fastening the systemboard into the chassis, attaching the cables in the relevant locations and then inserting the power supply. If using 2.5" drives then insert them into the internal drive bay and attach any cables. Finally fasten the 2.5" drive bay into position. There is not much room within the enclosure and this is a recommended method of installation.
The SDD drive was inserted into the internal drive bay on mine and then I inserted the other 6 drives into the drive carriers and placed them inside the NAS.
Next comes the installation. I made a bootable USB drive from the TrueNAS ISO using BalenaEtcher, connected a monitor and keyboard. Then powered the NAS on.
First of all went into the BIOS and made the SSD drive the bootable drive but put the USB drive first in the list so I could boot from the USB stick.
Simply follow the prompts on screen during installation, give the NAS an ipaddress, subnet, gateway and dns servers. The final thing you see on screen is a menu.
I disconnected the screen and keyboard and carried on by the url through a web browser.
From now on everything is controlled by the web gui and you can even shut it down.
I have configured the NAS to have
1 500GB Pool which contains the System DataSet Pool - This is 2 500GB disks that have been mirrored
1 8TB Pool which is for Astro work - This is 2 8TB disks that have been mirrored
1 8TB Pool containing media, music etc for use with Plex Media Serve - This is another 2 8TB disks that have been mirrored.
TrueNas does all the mirroring so you don't have to use any fancy hardware.
I have installed the Plex Media Server which is a plugin within TrueNas so no external server is needed for Plex. As the NAS has 32GB of internal RAM it runs Plex internally with no strain on the system.
All in all the hardware and operating system has made life a little easier and most of all the data is protected. I still do external offsite backups using Asigra (also a plugin for TrueNas) to ensure data integrity if the house goes up in flames 🙂 - I have worked in IT for donkeys years and backups are a way of life!