I created a proxmox server on which a truenas vm is running (hardware = old Tiny 2019), I created a pool with two mechanical disks plugged into the docking station connected via USB to my Tiny. The pool works great but to improve the speed I want to add two cached SSDs to improve reading and writing. So I add two SSDs, one in sata to usb adapter, the other direct in USB (external Samsung SSD) and Truenas tells me that the disks do not have a unique serial number, I don’t know what to do if someone 'someone understands the problem that would help me a lot
TrueNAS relies on direct access to the disks. Many USB adapters prevent that. The most common symptom being that TN cannot even read the disk’s serial number.
Without unique serial numbers TrueNAS cannot identify the disks. Plain and simple.
Avoid using USB-connected hard disks for primary storage with TrueNAS. You can use USB Hard Disks for very basic backups in a pinch. While TrueNAS does not automate this process, you can connect a USB HDD, replicate at the command line, and then take it off-site for safekeeping.