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

See stable disk names by hardware id

After by-uuid shows filesystem UUID paths, use a simple ls under /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.

A device letter like sdb1 can change when you unplug and replug. Linux already keeps another set of names under /dev/disk/by-id that follow how the hardware presents itself - serial and bus style, not the filesystem UUID. 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 filesystem UUID paths, that is see stable disk names by UUID. 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-id (and optional /dev/disk/by-path) are folders of short names Linux builds for you. Each name is a symlink - in plain English, a pointer that says “this hardware id is really /dev/sda (or sdb1) right now.”

Here is the one jargon split for tonight: by-uuid names come from the filesystem UUID (the tag blkid prints). by-id names come from how the hardware presents itself - often a serial and a bus prefix like ata-, usb-, or nvme-. Both stay put when the letter moves. Both are look-only tonight. You don't mount, unmount, format, or wipe anything.

Practice: list the hardware-style names

SSH in from the couch, then run:

ls /dev/disk/by-id

You should see a list of longer names - often starting with ata-, usb-, nvme-, or similar - plus partition suffixes like -part1 on some entries. In plain English: Linux already made a fixed hardware-style name for each disk (and often each slice) it can identify.

Optional: the same idea by how the disk is plugged in (controller / port style):

ls /dev/disk/by-path

Optional: see what each by-id name points at right now:

ls -l /dev/disk/by-id

The right-hand side is usually something like ../../sda or ../../sdb1. That is the symlink target - today’s device letter. Tomorrow the letter might change; the by-id 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 so you know today’s letter, then run ls /dev/disk/by-id (or ls -l). You should see a usb-… style name appear, pointing at today’s /dev/… name. Compare with by-uuid if you already know the filesystem UUID - same stick, two kinds of fixed 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 hardware-style 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 by-id name looks unfamiliar. Free room is disk-space. Disk names without tags are lsblk. Mount maps are findmnt. Printed labels and UUIDs are blkid. Filesystem UUID paths are by-uuid.

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-uuid. That lists filesystem UUID (and optional label) paths under /dev/disk/by-uuid: see stable disk names by UUID. 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

Want a deeper look at what udev knows about one disk? Peek at disk details with udevadm. Need filesystem UUID paths first? See stable disk names by UUID. Need labels and UUIDs printed? 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 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, by-uuid, disk-space, or total disk size as tonight's job if you only came for the stable /dev/disk/by-id 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 by-id name 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.