For a small business that relies on data, having a proper storage solution is absolutely crucial. Most of the time, you’ll want to have a Network Attached Storage (NAS) device because it’s an easy way to have multiple computers share data. Most people will know this as a “file server”.
I recently had the opportunity to set up such a solution, with the following requirements:
- Redundancy was important: Or in other words, there’s need for a high availability setup where if any hardware fails, there’s a second piece ready so that you don’t spend a day waiting for replacement parts.
- Backups were essential: Accidents have to be taken into consideration, and a recent backup of the data has to be available. Restoration should be immediate and not take too long.
- Downtime had to be minimised: Downtime is expected, especially when accidents happen, but should be minimised. Any cases of hardware failure, or data corruption, should result in minimal downtime.
Total usable capacity had to be at least 1.5TB. Because of the size of the data and the frequency of data transfer, I felt that a gigabit network was needed (think up to 125MB/s vs 12.5MB/s). This meant gigabit switches, wireless N 300 routers (which are the fastest in the market now), and CAT 6 cables.
Next up were the following questions that I came up with in order to arrive at the solution I needed:
1. What happens if the NAS fails / dies irreparably?
This means I had to get 2 NAS devices so that if the primary NAS fails, I can immediately take out the hard drives from the primary NAS, and put them into the secondary NAS and be up and running. (Confirmed with the official page: How to Migrate Between Synology NAS). The primary NAS will then have to be replaced immediately since the entire solution will then be running in a degraded mode, as only 1 NAS will be in operation.
2. What happens if a hard drive fails / dies irreparably?
Because of this possibility, I knew I needed to have some form of RAID. This also meant I needed a NAS with at least 2 bays.
3. What happens when data becomes corrupted because of a RAID failure, or is lost during migration?
To mitigate this risk, I will backup the data on to an external drive via USB. To ensure that I had a fairly recent copy of the data if this happened, I will also run this daily. This should be a 3.5″ external drive because of the larger/cheaper capacity available, and should also support USB 3.0 for the faster transfer speeds. The Mediasonic Smart Drive 3.5-Inch USB 3.0 External Enclosure is perfect for this.
4. What happens when both NAS units die?
Unlikely, but if this happens, my USB drive is still there. Also, I should use RAID 1, because it’s possible to take out a single drive and mount it within a PC, and use a bootable Linux distro to read off the data. Definitely not the most painless procedure, but at least my data is still retrievable – which is near impossible with other forms of RAID (i.e. RAID 0, RAID 5, RAID 6).
5. What happens when both NAS units, and all hard drives die at the same time?
I knew that even though there was a possibility of this happening, the chances of it happening are very remote, so I didn’t plan for this. What I did do though, is decide to keep a copy of the data offsite. I felt that the best way to do this is to take a seed of the data set, and place it on a NAS or server in an off-site location (because transferring 1.5TB of data will take a lonnnnnnng time). The NAS will backup incremental data to this location.
After researching on the various NAS options available, I chose to use the Synology ds213+ Diskstation NAS because of it’s features and reliability. The Synology ds213+ is a 2-bay NAS, which means it can accept up to 2 hard drives internally. My requirements to have RAID 1, and at least 2TB of usable data, is supported by the Synology ds213+ (see the official ds213+ page).
Also, it had the following features that made it very useful and sealed the deal for me:
- Easy-to-use, fast and responsive interface.
- Email/Skype/MSN/SMS alerts for pretty much anything you want. Think alerts whenever the disk quota is maxed out, or when a schedules backup process fails. Awesomely useful.
- Backup and restorations built-in. Great, especially if I wanted to backup/restore to another Synology NAS and my external USB drive on a scheduled basis.
- USB ports for my external USB hard drive.
- In-built Dynamic DNS support for most major providers. If you’re thinking of exposing your NAS to the internet, this is useful because you can get a DDNS hostname and not have to worry about your IP address changing because the NAS updates your DDNS provider about your network’s new IP address.
- Remotely accessible management interface – a real godsend, especially during the setup phase, because this means that you can be overseeing the setup progress of your NAS from a Starbucks.
I bought 2 units of this NAS.
Researching suitable hard drives for NAS usage led me to Western Digital (WD) Caviar Green and Caviar Red hard drives. The Caviar Red seemed to be made for NAS, but I read a bunch of reviews that seemed to show that it wasn’t worth the slightly higher price premium. I personally had a lot of good experience with the WD Caviar Green hard drives, having used them for years without problems in previous NAS devices, and even for servers, so I went with them again and bought 5 drives.
The following diagram will illustrate the exact solution that I have:
The primary NAS will be the main fileserver in use in daily operations. The primary NAS will automatically make full backups to the secondary NAS, and to the external USB drive. Every week, the primary NAS will make a backup to the offsite location as well.
Setting up the NAS was a breeze. By default, Synology uses the Synology Hybrid RAID (SHR) format to create volumes, so I had to delete off the default volume and create a custom one based on RAID 1. The rest of the setup process was so painless that it could even be considered to be fun.
I hope documenting the steps that I took to achieve this setup has helped you.