Recommended flash drives for user folder storage?

[keboose]

I have a remote FreeNas system (currently running 11.3 latest, or one version behind) that I use to backup my main NAS to. In my hubris, I enabled full disk encryption on the backup pool, and now that I have multiple terabytes replicated into it, I don't want to tear it apart to remove the encryption. From the get-go, I used mirrored flash drives to store my user home directory, literally all that's on it is a single (empty) user home with the SSH public keys I use to log in (every time the server reboots I have to log in and unlock the backup pool; password login disabled, root login disabled.)

This worked for a while, but for some reason I am churning through flash drives. I tried using those tiny Sandisk Cruzer Fit drives (about the size of a modern wireless mouse dongle), and they were dropping out after only a month or two. I should also mention that due to the form factor of the case I chose, I don't have space for any extra internal drives.

I don't know if it's a quirk of my hardware or something else (I don't think I'm hitting these drives nearly hard enough to wipe them out this fast), but I feel I should try a different brand/style of drive. does anyone have suggestions for more durable flash drives?

 

[subhuman]

As you've seen, flash drives just don't have sufficient write endurance for day-to-day usage.
You say the case is size-constrained, but can you get creative and fit an SSD in there somewhere? Velcro, tape, cable ties- whatever works.
You can try a USB to M.2 NVMe adapter and put a small SSD in it, it will be physically larger than what you've been using but will have better write endurance.
You might have luck with USB to SD/microSD adapter and a decent card (super low-end cards usually do not do wear levelling). However I think that would be less effective and at least as expensive as the previous M.2 NVMe option.

 

[keboose]

I've unfortunately used all the sata ports on the motherboard, so extra SATA ssd's aren't an option (two for boot drives, two for storage drives.) The only available ports on the motherboard are a single PCIe-16x slot, and USB headers (It's the "Backup Nas" specs in my signature.)

PCI/USB SSD adapters are an option. The USB 3.0 header on my motherboard is free, it would be ideal to find an adapter from m.2/nvme to either a USB 3 or 2 header. It looks like it would cost about $10 for a USB3.0 header-->Type A female adapter, $12 each for M.2-->USB adapters, and whatever M.2 SSD I can find. This would probably fit internally if I glued the adapters to the removable top panel of my case, but the case is small enough that, as ridiculous as it sounds, the extra cable mess and components could measurably impact the airflow through the case.

I like the idea of SD cards though. I helped a friend pick out a dashcam for their car a little while ago and we discovered "high endurance" sd cards for continuous recording. I already have a ton of USB SD card adapters, so hopefully the fact that two of these cards cost the same as the 5-pack of flash drives I previously bought (and since burned through,) means they can handle it better.

I think I'm going to try the SD card option first. I'm hesitant to spend $50+ for what is essentially storage for my authorized_keys file, but I can justify $25.