Not related to USB, but flash storage quality in general varies a lot.

We have a few hundred Raspberry Pi in operation at customer sites, running 24/7. Back when we started our business we used generic Micro SD (can't remember the brand). They would fail after 2-6 months. This was a big hassle. We have customers all over Germany and would need to ship them a complete RPI as a replacement, as the customers are usually not tech-savvy enough to just replace the SD.

We now use SanDisk's "Industrial" Micro SD and haven't had this problem since.

Also, reducing writes to the SD is certainly a good idea. Ideally - if you can - mount the system as read only.

Interesting you mention "Industrial" cards as I have been looking at cards in this range after reading quite a few issues with RPIs over the past few months. I have a RPI3 with a SanDisk Extreme, running for 18 months 24/7 with no issues yet. Plenty of re-imaging and high temps. RPI 4 has a SanDisk Ultra, only been running for 3 months 24/7. Now whilst we all should have backups anyway, I really don't want the worry or hassle of restoring backups couple of times a year, I would rather have a card that will last years rather than months.

Slightly off topic but I have also been looking at using net boot instead. Not only would it be just as fast as the Micro SD cards but much easier to perform backups locally and offsite.

Most of the usb sticks seem to perform about the same as microSD cards, and I wouldn't trust them (especially the tiny ones that get super hot like the Ultra Fit) for booting anything important. USB SATA/NVMe SSDs are just as reliable as internal drives, in my experience. I've had a few of them running 24x7 on my NAS for years (with decent amounts of activity).

And the Corsair GTX, while massive, is as fast as an SSD and supports UASP and TRIM. It's just big, and relatively expensive, for a 'thumb drive'.

"USB attached storage" includes not only USB sticks, but many other devices, e.g. memory cards or SSD's connected through UDB adapters.

I have run 24/7 many SSD's attached via USB, with no reliability problems.

Usually buying SATA or NVME SSD's and separate USB adapters for them is cheaper than buying USB SSD's, which actually contain an internal USB adapter.

I ran 5 USB drivers (4x USB3 and 1x USB2) of a powered USB3 hub attached to a RPi4 a few weeks back as was clearing up some drives and data juggling between them. Had that running for few days with no issues at all and was thrashed a few times with moves/copies across all the drives.

So indications are good, and the drives in this case was a WD SSD, 3x Toshiba bus powered drives and an ancient 320gb usb externally powered WD affair. So a but of a mix. Though I did have it plugged into a UPS, which like all things tech - kinda helps smooth out the random chaos of electricity and tech.

Most storage corruption problems related Rasberry PIs are just PSU problems. Flash drives and SD cards draw their power directly from the Rasberry PI and since those only use a crappy micro USB port or a buggy USB C port you're going to run into issues, especially if you use a random USB charger instead of the official power supplies. External storage like an SSD that uses its own power supply (via the USB hub) will be far more reliable.

I will just share my experience with a usb stick.

I have used a usb stick (SanDisk Ultra Fit) for the Freenas O.S.. That drive died in 6 months (24/7). In general Freenas suggests to use 2 mirrored, quality, name-brand USB drives as they can `wear out or fail unexpectedly`[1]. They not suggest USB drives for data storage and I never tried.

[1] https://www.ixsystems.com/documentation/freenas/11.3-U4/intr...

I use a raspberry pi 4 (before that 3b) as NAS. A usb harddrive is used for data storage. The workload is low, mostly photos and music streaming, but I've not seen USB problems so far.

Been running hdd attached to Pis myself for hundreds of days without interruptions.

My seagate drive died after 2 years of being connected to my pi and on full time.

Been running 2 Samsung 500GB ssd (1 USB3 direct, 1 via USB3 hub) on rpi4 24/7 since boot from USB first landed (May?). Mostly video recording/backup workload. I’ve had no issues and sitting at 36d uptime right now.

I wouldn't trust any of those USB sticks for anything other than very light, mostly read-only use. However the SSD and NVME drives are likely to be a lot more reliable - since they are just desktop NVME/SSDs in a shell that converts the interface to USB 3 they are as reliable as an NVME/SSD in a desktop or laptop.

Be aware (as I found out a couple of days ago) the RPi 4 USB port cannot power an external USB hard disk unless you use a separate powered hub. Should be fine to use a USB SSD / USB NVME though.

I've been using an external portable (2.5") seagate drive[0] for a while with my pi 4 to hold music and videos. It's plugged straight into the USB 3 port with no problems so far.

You will have problems trying to power a desktop 3.5" drive though.

[0] https://www.amazon.co.uk/Seagate-Expansion-Portable-PlayStat...

I’ve been running a NUC as a home server, with a cheap dual bay USB 3.1 to SATA enclosure, for about two years now. I haven’t had any reliability issues with it.