On Fri 10 Dec 2021 at 17:20:52 (+0100), Andrei POPESCU wrote: > On Lu, 06 dec 21, 10:18:49, David Wright wrote: > > On Sun 05 Dec 2021 at 13:33:41 (+0100), Andrei POPESCU wrote: > > > On Vi, 12 nov 21, 12:27:59, Stefan Monnier wrote: > > > > > > > > As mentioned, the way to control it will depend on the specific tool > > > > used to mount. E.g. if it's mounted by hand via a rule in /etc/fstab, > > > > then you can rules that specify the device via /etc/disk/by-uuid. > > > > > > > > Do note that partition UUIDs are not designed to be reliable w.r.t > > > > malicious uses (it's easy to create a partition with the same UUID as > > > > some other). > > > > > > /dev/disk/by-id/ should be device specific. > > > > It certainly is, but specific to the card reader reading it, > > not the card. And that's whether the card is plugged into a > > slot on the computer, or into a discrete SD/USB adapter. > > At least with the built-in reader on an Acer Chromebook R13 the ID > changes with every card I tested, but you are indeed right about USB > adapters (at least for the two I could test).
I did some comparisons between machines, and it would appear that when the link starts with /dev/disk/by-id/mmc- then the ID is that of the card, whereas when it starts with /dev/disk/by-id/usb- then the ID is that of the card reader. Note that I did all the comparisons using fullsize SD cards pushed into slots in the PCs, so there were no separate adapters involved, neither SD→USB, nor µSD→SD. As one might expect, googling mmc and usb is swamped with stuff about MMC and SD /cards/, so I haven't read anything about the differences between these slots on different computers. But I guess that if you want to distinguish SD cards by their identification/serial number, rather than strings that you write onto them (UUID/LABEL), you need to use a PC with an mmc-style slot. Cheers, David.
