Written 2 Sep 2026. This is a how-to, not a product card.

See stable disk names by UUID

After blkid shows labels and UUIDs, use a simple ls under /dev/disk/by-uuid (and optional by-label) so you see the fixed paths Linux already made - names that don't move when sdb becomes sdc.

A device letter like sdb1 can change when you unplug and replug. Linux already keeps a second set of names under /dev/disk/ that stay put. Tonight you only list those folders. You don't mount, format, wipe, or rewrite fstab.

Skip until SSH works

If you cannot log in from the couch yet, stop. That is SSH from the couch. Stable paths don't help a login that fails.

If you only need the list of disks and USB sticks, that is see disks and USB sticks (lsblk). If you only need which folders are already attached, that is see which folders are already attached (findmnt). If you only need labels and UUIDs printed as text, that is read disk labels and UUIDs (blkid). If you only need hardware-style fixed names, that is see stable disk names by hardware id. If you only need room left on a path, that is see if the computer still has room (df).

What this is

/dev/disk/by-uuid and /dev/disk/by-label are folders of short names Linux builds for you. Each name is a symlink - in plain English, a pointer that says “this UUID (or label) is really /dev/sda1 right now.” The letter at the end can move. The UUID path stays the same. Tonight you take a look with ls. You don't mount, unmount, format, or wipe anything.

Practice: list the stable names

SSH in from the couch, then run:

ls /dev/disk/by-uuid

You should see a list of long IDs - the same UUIDs you saw in blkid, now as folder entries. In plain English: Linux already made a fixed name for each slice that has a recognizable filesystem.

Optional: the same idea by friendly label (only slices that have a LABEL show up):

ls /dev/disk/by-label

Optional: see what each UUID name points at right now:

ls -l /dev/disk/by-uuid

The right-hand side is usually something like ../../sda1 or ../../sdb1. That is the symlink target - today’s device letter. Tomorrow the letter might change; the UUID entry stays. Home-safe look only. Don't format, wipe, remount, or edit fstab tonight.

Optional: after you plug in a USB for backup

Plug the stick into the computer. Run lsblk and blkid so you know the letter and the UUID, then run ls /dev/disk/by-uuid (or ls -l). You should see that UUID appear, pointing at today’s /dev/… name. If you need the mount map next, that is see which folders are already attached. The backup job, once a path is live, is a backup of the folder.

Useful extras, still a look

Skip mount and umount as the job. Tonight you list the stable names Linux already made.

Skip rewriting disks, dd, shred, fdisk, parted, format, or rewriting fstab as the lesson. Those are not this note.

Skip buying a NAS because a UUID looks unfamiliar. Free room is disk-space. Disk names without tags are lsblk. Mount maps are findmnt. Printed labels and UUIDs are blkid.

Skip screen, tmux, and port 22 forwarding. Keep SSH on the house network: keep the computer on the house network.

Skip awk, sed, and install as new pages this cycle.

What this is not

This is not lsblk. That lists disks and USB sticks by name: see disks and USB sticks. It is not findmnt. That shows which folders are already attached: see which folders are already attached. It is not blkid. That prints LABEL, UUID, and TYPE as text: read disk labels and UUIDs. It is not by-id. That lists hardware-style fixed names under /dev/disk/by-id: see stable disk names by hardware id. It is not disk-space (df). That shows how full a mounted path is: see if the computer still has room. It is not disk, which focuses on how big the main disk already is: see how big the disk already is. It is not USB-disk, a shorter “did the stick show up?” check: see if the USB backup disk showed up. It is not the backup copy itself: a backup of the folder.

What next

Need labels and UUIDs printed first? Read disk labels and UUIDs. Need the disk-name list? See disks and USB sticks. Need which folders are already attached? See which folders are already attached. Need hardware-style fixed names under /dev/disk/by-id? See stable disk names by hardware id. Need room left on a path? See if the computer still has room. Stick visible and ready for a second copy? A backup of the folder. Need how big the main disk already is? See how big the disk already is. Keep SSH on the house network: keep the computer on the house network. awk, sed, and install stay deferred this cycle.

Skip

Skip if SSH still fails. Finish SSH from the couch first.
Skip lsblk, findmnt, blkid, disk-space, or total disk size as tonight's job if you only came for the stable /dev/disk/by-uuid names. Those notes already exist.
Skip mount/umount as the lesson, and skip rewriting disks, dd, shred, fdisk, parted, format, and rewriting fstab.
Skip buying a NAS because a UUID looks unfamiliar.
Skip awk/sed/install as new pages this cycle, screen, tmux, and port 22 forwarding.
Skip opening SSH to the internet. That is keep the computer on the house network. Don't forward port 22.

Sources

Debian: ls(1). Ubuntu: ls(1). Device naming under /dev/disk/ is standard Linux (udev); see also Debian: blkid(8) for how UUIDs are read. Official pages only. For printed labels and UUIDs, see read disk labels and UUIDs. For the disk-name list, see see disks and USB sticks. For the mount map, see see which folders are already attached. For free room, see see if the computer still has room. For a second copy once a USB path is live, see a backup of the folder. For the login, see SSH from the couch.

Also on this topic

SSH from the couchType commands on the computer from your laptop, on the house network. Password login first. Don't open this to the internet. See disks and USB sticksAfter SSH works (and before you blame a missing USB backup), list disks and USB sticks with lsblk so you see names like sda and sdb without opening a disk app. See which folders are already attachedAfter you can list disks with lsblk (and before you blame a missing USB backup), use findmnt to see which folders are already attached (mounted) so you know what is live as / or a USB path. Read disk labels and UUIDsAfter you can list disks with lsblk and see which folders are attached with findmnt, use blkid to read labels, UUIDs, and filesystem types on disk slices so you can tell which stick or slice is which. See stable disk names by hardware idAfter by-uuid shows filesystem UUID paths, use ls on /dev/disk/by-id (and optional by-path) so you see hardware-style fixed names - ata-…, usb-…, nvme-… - that don't move when sdb becomes sdc. See if the computer still has roomAfter the house folder is working, check that the computer is not filling up. Photos stop copying when the disk is full. You don't need a NAS for this look. See how big the disk already isBefore you buy a tiny computer or a NAS, check how big the computer disk already is. See if the USB backup disk showed upBefore you trust the weekly copy, confirm the computer can see the USB disk. A backup of the folderA second copy of the house folder, on a USB disk you already have, or on another leftover computer. You don't need a NAS for this. Keep the computer on the house networkSSH and Pi-hole belong on the house network. Skip this if you never opened the router settings. Don't forward port 22.