Labthrift Labthrift What to buy. What to skip. Why.

Written 2 Sep 2026. This is a how-to, not a product card. Buy links are not tagged yet.

See stable leftover-box 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 do not 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 do not 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 do not help a login that fails.

If you only need the list of disks and USB sticks, that is see disks and USB sticks on the leftover box (lsblk). If you only need which folders are already attached, that is see which leftover-box folders are already attached (findmnt). If you only need labels and UUIDs printed as text, that is read leftover-box disk labels and UUIDs (blkid). If you only need filesystem UUID paths, that is see stable leftover-box disk names by UUID. If you only need room left on a path, that is see if the leftover box 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 do not mount, unmount, format, or wipe anything.

Practice: list the hardware-style names

SSH in from the couch, then ask:

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. Do not format, wipe, remount, or edit fstab tonight.

Optional: after you plug in a USB for backup

Plug the stick into the leftover box. 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 leftover-box folders are already attached. The backup job, once a path is live, is a backup of the leftover-box folder.

Useful extras, still a look

Skip mount and umount as the job. Night one is listing 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 leftover-box disk-space. Disk names without tags are leftover-box lsblk. Mount maps are leftover-box findmnt. Printed labels and UUIDs are leftover-box blkid. Filesystem UUID paths are leftover-box by-uuid.

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

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

What this is not

This is not leftover-box lsblk. That lists disks and USB sticks by name: see disks and USB sticks on the leftover box. It is not leftover-box findmnt. That shows which folders are already attached: see which leftover-box folders are already attached. It is not leftover-box blkid. That prints LABEL, UUID, and TYPE as text: read leftover-box disk labels and UUIDs. It is not leftover-box by-uuid. That lists filesystem UUID (and optional label) paths under /dev/disk/by-uuid: see stable leftover-box disk names by UUID. It is not leftover-box disk-space (df). That shows how full a mounted path is: see if the leftover box still has room. It is not leftover-box disk, which focuses on how big the main disk already is: see how big the leftover box disk already is. It is not leftover-box 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 leftover-box folder.

What next

Want a deeper look at what udev knows about one disk? Peek at leftover-box disk details with udevadm. Need filesystem UUID paths first? See stable leftover-box disk names by UUID. Need labels and UUIDs printed? Read leftover-box disk labels and UUIDs. Need the disk-name list? See disks and USB sticks on the leftover box. Need which folders are already attached? See which leftover-box folders are already attached. Need room left on a path? See if the leftover box still has room. Stick visible and ready for a second copy? A backup of the leftover-box folder. Need how big the main disk already is? See how big the leftover box disk already is. Keep SSH on the house network: keep the leftover box on the house network. Leftover-box-awk, leftover-box-sed, and leftover-box-install stay deferred this cycle.

Skip

Sources

Debian: ls(1). Ubuntu: ls(1). Device naming under /dev/disk/ (including by-id and by-path) is standard Linux (udev). Official pages only. For filesystem UUID paths, see see stable leftover-box disk names by UUID. For printed labels and UUIDs, see read leftover-box disk labels and UUIDs. For the disk-name list, see see disks and USB sticks on the leftover box. For the mount map, see see which leftover-box folders are already attached. For free room, see see if the leftover box still has room. For a second copy once a USB path is live, see a backup of the leftover-box folder. For the login, see SSH from the couch.

Also on this topic

SSH from the couchType commands on the leftover box from your laptop, on the house network. Password login first. Do not open this to the internet. See disks and USB sticks on the leftover boxAfter 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 leftover-box 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 leftover-box 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 leftover-box disk names by UUIDAfter blkid shows labels and UUIDs, use ls on /dev/disk/by-uuid (and optional by-label) so you see the fixed paths Linux already made — names that do not move when sdb becomes sdc. Peek at leftover-box disk details with udevadmAfter by-id shows hardware-style fixed names, use udevadm info (look-only) on a disk path so you see the properties udev already knows — without mounting or rewriting anything. See if the leftover box still has roomAfter the house folder is working, check that the leftover box is not filling up. Photos stop copying when the disk is full. You do not need a NAS for this look. See how big the leftover box disk already isBefore you buy a tiny computer or a NAS, check how big the leftover box disk already is. See if the USB backup disk showed upBefore you trust the weekly copy, confirm the leftover box can see the USB disk. A backup of the leftover-box folderA second copy of the house folder, on a USB disk you already have, or on another leftover computer. You do not need a NAS for this. Keep the leftover box on the house networkSSH and Pi-hole belong on the house network. Skip this if you never opened the router settings. Do not forward port 22.