Hardrive suddenly unallocated

woofercooker · 1 Jan 2026 at 15:18

One of my external usb caddy hardrives suddenly stopped showing up, i went into disck manager and noticed it was listed as unallocated, i assumed it had failed, i downloded a program at random diskdrill to see if i could recover any files and that program brough up litteraly everything no problems at all, its just like browsing my hardrive as if nothing happend. I need to but the full version of the product and another hardrive to recover everything too but any idea what caused this and is there a way to recover to the same hardrive or do you need a new one, there isn't really any imporant data i need but i would still like to keep the stuff on there if i can, its just stuff i've downloaded which could easily be downloaded again but id like to still try and see if i can still save the drive is possible.

paul10 · 1 Jan 2026 at 17:39

exactly the same issue as you unallocated drive wd duo 20tb except when i used diskdrill it found a load of stuff on top that i had deleted ,so instead of the 6tb i thought i had it actually resulted in 12tb at first i thought it was because i had raid 1 array set up on my external drive but no it has found a mass of deleted removed folders that i thought i had removed a real pita ,spent 36hrs recovery on to a qnap das 36tb set ,it may have been a hack or malware that caused the issue i also noted i had a corrupted windows code with a transulcent mask in the corner of my pc ask for windows update or something of this description.previous to this i had done two bios updates for my motherboard flash usb ones this resulted in me requiring a boot up and change of windows password pin

Cyber-Mav · 22 Jan 2026 at 14:34

Usb caddy using jmicron controller?

Bubo · 5 Feb 2026 at 06:19

Cyber-Mav said:
Usb caddy using jmicron controller?

Is there a known issue with jmicron controllers? I've been having some random disconnectd with external data ssds in caddys with this controller just recently.

Cyber-Mav · 5 Feb 2026 at 06:48

Yes iv had no end of issues with jmicron and asmedia.
Now iv got 8 caddy's all using realtek and not a single issue. So when I'm on the hunt for external data or nvme enclosures I always check to make sure they use realtek chipset

rids57 · 11 Feb 2026 at 08:35

Just had a HD go unallocated for the second time in the same slot of a 6 slot Terramaster. Not sure if it's the drive or the controller and I'm not putting any of my much more important drives in that slot to try it out. The drive is an old 2TB WD Green so not really suitable for the task but I had an empty slot so threw it in anyway. Maybe I'll just get a new large NAS or enterprise drive to upgrade one of the others (up to 10TB) and move my scratch disk to the questionable slot.

Bubo · 2026-02-26T09:59:04+0000

Cyber-Mav said:
Yes iv had no end of issues with jmicron and asmedia.
Now iv got 8 caddy's all using realtek and not a single issue. So when I'm on the hunt for external data or nvme enclosures I always check to make sure they use realtek chipset

Thought I'd update this, I did a google and the apparent solution to was flash a fixed firmware to caddies with the troublesome JMS578 controller, and since I did that I haven't had any random disconnects. I did note the the firmware on the drive before flashing was actually a later version number, so I guess this fix is a rollback of sorts, but it seems to have fixed it anyway. Also did this on all my caddies which had the same controller chip.