After two years of use, my USB3 external 8TB backup drive stopped responding as an external disk. I took apart its enclosure and extracted a standard 3.5" hard disk drive which seems OK in perfunctory testing. In order to continue using it for TrueNAS replication backup, I'll need another enclosure. I briefly contemplated getting an USB3 SATA enclosure that takes 3.5" drives (*) but I decided to use an entire computer as its enclosure: I have an old Dell Optiplex 960 SFF (small form factor) PC collecting dust and it would be more useful as my TrueNAS replication backup machine.

Dell's Optiplex line is aimed at corporate customers, which meant it incorporated many design priorities that weren't worth my money to buy new. But those designs also tend to live well past their first lives, and I have bought refurbished corporate Dells before. I've found them to be sturdy well-engineered machines that, on the secondhand market, is worth a small premium over generic refurbished PCs.

There's nothing garish with exterior appearance of an Optiplex, just the computer equivalent of professional office attire. This particular machine is designed to be a little space-efficient box. Office space costs money and some companies decide compactness is worth paying for. Building such a compact box required using parts with nonstandard form factors. For a hobbyist like me, not being able to replace components with generic standard parts is a downside. For the corporate IT department with a Dell service contract, the ease of diagnosis and servicing is well worth the tradeoff.

This box is just as happy sitting horizontally as vertically, with rubber feet to handle either orientation.

Before it collected dust on my shelf, this computer collected dust on another maker's shelf. I asked for it sometime around the time I started playing with LinuxCNC. I saw this computer had a built-in parallel port, so I would not need an expansion card. (Or I can add a card for even more control pins.) The previous owner said "Sure, I'm not doing anything with it, take it if you will do cool things with it." Unfortunately, my LinuxCNC investigation came to a halt due to pandemic lockdown and I lost access to that space. TrueNAS replication target may not be as cool as my original intention for this box, but at least it's better than collection dust.

Even though the chassis is small, it has a lot of nice design features. The row of "1 2 3 4" across the front are diagnostics LEDs. They light up in various combinations during initial boot-up so, if the computer fails to boot corporate IT tech support can start diagnosing failure before even opening up the box.

Which is great, because opening up the box might be hindered by a big beefy lock keeping the side release lever from sliding.

And if we get past the lock and open the lid, we trip the chassis intrusion detection switch. I've seen provision for chassis intrusion detection in my hobbyist-grade motherboards, but I never bothered to add an actual intrusion switch to any of my machines. Or a lock, for that matter.

Once opened I find everything is designed to be worked on without requiring specific tools. This chassis accommodates two half-height expansion cards: One PCI and one PCI-Express. On my PCs, expansion endplates are held by small Philips-head screws. On this PC, endplates are retained by this mechanism.

A push on the blue button releases a clamp for access to these endplates.

Adjacent to those expansion slots is a black plastic cage for 3.5" Hard drive.

Two blue metal clips release the cage to flip open, allowing access to the hard drive. This drive was intended to be the only storage device hosting operating system plus all data. I plan to install my extracted 8TB backup storage drive in this space, which needs to be a separate drive from the operating system drive, so I need to find another space for a system drive.

Most of the motherboard is visible after I flipped the HDD cage out of the way. I see three SATA sockets. One for the storage HDD, one for the DVD drive, and an empty one I can use for my system drive. Next to those slots is a stick of DDR2 RAM. (I'm quite certain Corsair-branded RAM is not original Dell equipment.) Before I do anything else with this computer, I will need to replace the CR2032 coin cell timekeeping battery.

A push on the blue-stickered sheet metal button released the DVD drive. Judging by scratches, this DVD drive has been removed and reinstalled many times.

Putting the DVD drive aside, I can see a spare 3.5" drive bay underneath. This was expected because we could see a 3.5" blank plate in the front of this machine, possibly originally designed for a floppy disk drive. The good news is that this bay is empty and available, the bad news is that a critical piece of hardware is missing: This chassis is designed to have a sheet metal tray for installing a 3.5" drive, which is not here.

I can probably hack around the missing bracket with something 3D-printed or even just double-sided tape. But even if I could mount a small SSD in here, there are no spare SATA power connector available for it. This is a problem. I contemplated repurposing the DVD drive's power and data cables for a SSD and found adapters cables for this purpose. (*) But under related items, I found a product I didn't even know existed: an optical-to-hard drive adapter (*) that doesn't just handle the power and data connectors, it is also a mechanical fit into the optical drive's space!

(*) Disclosure: As an Amazon Associate I earn from qualifying purchases.