Over the last few years I lived in many different locations and used different computer equipment, not acknowledging the crucial need for backing up data. My photographic repository was messy. It involved random USB hard drives, SSDs, a desktop computer and a few laptops I changed every two years. At some point, I went back to analogue photography which required digitising the negatives. It only added to the overall hullabaloo of my photo catalogue. At least two times I was close to losing large parts of it. Some time ago, I decided to do something about it and experimented with different hardware and software solutions. In this post, I am sharing my discoveries and providing possible solutions, depending on your needs, budget and physical constraints.

DAS: advantages and constraints

Among other companies, OWC provides numerous Desktop Attached Storage (DAS) solutions. Most of their dual-, quattro- and octa-bay solutions are software RAID ones. It means that you either need to use OWC proprietary SoftRAID software or rely on your OS capabilities. As for the former, not all products come with a license. Those that do have it only for three years. SoftRAID is pricey and offer little to no advantage over the latter option. Using tools embedded into MacOS or Windows sounds far more straightforward. Especially for MacOS users, the ability to create encrypted APFS drives is tempting as it provides a good level of protection on a daily basis. Imagine leaving a disk enclosure on your desk in a busy workplace shared by many random people. Anyone with a laptop and a right port (USB-A, USB-C/Thunderbolt) can access your data with no restrictions. This point is something that Windows users should be particularly mindful of. Microsoft’s encryption mechanism, BitLocker, works only on basic disks. It means that no software-based RAID volume one creates (either for redundancy or increased capacity and speed) can be BitLocker-encrypted. BitLocker can only be used with single drives. While for some it can be a major issues, for other it might become a minor limitation.

I have used several enclosures from OWC. Mercury Elite Pro Dual has worked best for compatibility reasons. It utilises USB 3.2 interface, making it accessible from most desktops, laptops and tablets out there. It also gives a modest port expansion, acting like a hub. What I particularly like about this enclosure is that it hosts a hardware RAID controller which makes it independent from any software-based solution. Once you populate it with drives, power it on, set the desired RAID mode and press one button, it automatically prepares the drives to be used.

As for software RAID options, I owned OWC’s Gemini Thunderbolt 3. It might be a faster option due to its THunderbolt 3 functionality (technically, it offers up to 40 Gbps transfer rates) and an even broader selection of ports, including an SD card reader. The downside of this enclosure is its limited compatibility and the mentioned lack of software RAID. I am very pleased with the Thunderbay 4 Mini, though. It hosts four 2.5-inch SATA HDDs and SSDs. As it includes two Thunderbolt ports, it can either be daisy-chained with another storage devices or provide connectivity for other peripherals plus a modest 15W charging capacity. The main TB port offers 27 watts, which suffices for the Apple Silicon Macbook Air lineup.

The main downside of all OWC enclosures I have used is the fan noise. For some reason, OWC uses basic Sunon fans in most of their products. I have seen units with Noctua fans in them, but they are rare. Since the connector on the OWC mainboards is not a standard 4-pin one, replacing the loud fan requires a bit of tinkering. I did it and it works flawless. My Thunderbay 4 Mini is now almost dead quiet as I populated with with SSDs.

NAS: extra cost might be worth it

Network Attached Storage uses a similar form factor to DAS but is primarily built to operate together in an environment where multiple devices and users need to have access to the same files. In the case of DAS, synchronisation and cross-platform compatibility can be a nuisance. DAS usually relies on user’s own software solutions. If you use Windows, want to encrypt your drives with BitLocker and prefer NTFS over anything else, you will either have to buy expensive MacOS software to access your data from a Mac or will have to duplicate your files using a different piece of hardware. On top of that, forget about unimpeded access from your mobile devices.

This is where NAS comes in handy. It offers a standalone software and hardware system accessible form your local network and, after fulfilling certain conditions, the internet. It is basically a full-fledged computer with an operating system run via web browser. So good so far but where is the catch? Its speed depends on a number of components: RJ-45 ports on the NAS itself (these days ranging mostly from 1 Gbit all the way to 10 Gbits), your router’s/switch’s speed, type of connection with end clients (Wi-fi or LAN), type and speed of drives installed, as well as the way they are configured. Be prepared: getting it all nice and quick will cost you a lot of money. At best, you might have to buy a 5/10 Gbit RJ-45 to USB-C adapter. At worst, you will have to invest a hefty sum into more peripherals or even get a new computer.

My personal favourite is Synology. It is not only the quality of hardware and how intuitive the initial setup is (adding drives, expansions cards, additional RAM etc.), but also the DSM ecosystem. I own two NAS enclosures from Synology: the two-bay DS-720+ (there is a newer version available, DS-723+) and the four-bay DS-923+. The former acts as a backup storage for the latter, which in turn hosts a copy of all my stationary files and recovery backups of the system drives of my computers. Over the years, this solution has worked best for me. I have access to my projects from any location as long as at least one of the NASes is up and running. I also do not have to concern myself with synchronising files – it is done automatically thanks to Synology Drive Client.

Seven hints from me

Here are some pieces of practical advice based on my experience:

• The 3-2-1 rule is a bare minimum. There is no such things as too many backups providing you have control over them. A good backup needs to stay up-to-date, be easily accessible and offer straightforward restore options.
• Be mindful about your needs and the conditions in which you will store your physical backups. More drives means more noise, more energy consumption, more space taken on your desk and more risk of something going wrong. Buying a sophisticated system with a very high capacity makes sense only if you know you will utilise it either immediately or fill it up over your system’s lifespan as…
• …Every HDD and SSD will fail one day. You can extend their functioning by turning them off when unused, ensure right operating environments (lowering ambient temperatures, improving airflow and eradicating humidity). Still, do not rely on only one drive, be it mechanical or silicone. RAID 1/5/6 configurations offer you some degree of protection against losing your data in a cafe of drive failure. If you go for any of these, they will to a large extent determine the architecture of your setup, such as the number of driver, their capacity or type of enclosure you want to go for. They will also constitute the lion’s share of your initial costs. You might think that going for a small, two-bay NAS with, for instance, 18 TB drives configured in RAID 1 might be cheaper than same capacity setup in four- or six-bay enclosure set to RAID 5 but it might not hold true. Four 6 TB HDDs (3 plus 1 for redundancy) will most likely cost lest than two behemoths of 18 TB each.
• Online cloud services can only provide a short-term solution to the challenge of working with many large files. If your internal hard drive is small and you have to download large files as you work on them, you will need a reliable and speedy internet connection. In most cases, however, it will still be too slow to meet your needs especially if you are on the go, need to work on a large repository of files and do not trust external drives (it is so easy to lose them, after all). Consider investing a larger internal SSD (in this day and age 2 TB does not sound crazy). I know it is a costly thing to do, especially for Mac users who need to make this decision at the time of purchasing their device.

• Encryption is essential for both mobile and stationary working environment. It is understandable that you want you data to be safe on the go as it is not unseen to lose your ultra portable, tiny SSD. Yet it is equally important to know that your stationary storage, be it a NAS, an external desktop enclosure or just drive you keep in your desk drawer are not an open book when falling into the wrong hands.

• NAS is an attractive option to keep your files accessible from anywhere in the world and synchronised across your devices if you work with other large storage pools. It can also be a reliable backup option, depending on the way you configure your NAS storage pool. It also offers the widest cross-platform compatibility possible as the file systems it utilises are not an obstacle in accessing your files from different devices, such as Windows, Linux and Mac computers, as well as Android and iOS/iPadOS phones and tablets.
• High quality hardware can save you from really big trouble and ensure stable performance over long time periods. Most hard drive companies have a dedicated enterprise series of their HDDs. They have longer running times, often stretching to 2,500,000 hours, offer large cache and ensure compatibility with NAS devices. The differences in price-to-gigabyte ratio are often small enough to neglect them.

As I am writing this post, Thunderbolt 5 is making its way into consumer electronics. In early to mid-2025, there is only a modest albeit a growing selection of desktops and notebooks with TB5 ports. It’s only a matter of time when devices such as DAS hit the market. They can deliver substantial progress when it comes to speed with their 80 Gbps (dynamically expandable to 120 Gbps if needed) bidirectional bandwidth. 10 GB/s of transfer means that using external NVMe enclosures will allow these disks to run at their full speed. It also means that multi-drive pools of SATA SSDs can become a fast and an affordable way of storing and processing large amounts of data.

Featured image source: https://commons.wikimedia.org/wiki/File:Exabyte_EXATAPE_AME_8mm_Data_Cartridge.jpg