I made
mount | tee mountbefore
mount | tee mountafter
diff mountbefore mountafter
Blank line

If flash disk is inserted into consoles of the thin client when to gather lsblk I see

sda   30G  disk
sda1  30G  part

But there are no mount points. I can make
sudo mkdir /mnt/1
sudo mount /dev/sda1 /mnt/1
ls /mnt/1
I see directories and files of the flash drive
If I correctly understand a disk does not mount on the thin client.

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