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

Read leftover-box disk labels and UUIDs

After 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 without opening a disk app or formatting anything.

A device name like sdb1 can change when you unplug and replug. A label is the friendly name someone put on the slice. A UUID is a long fixed ID for that slice. Filesystem type is the flavor on the disk (ext4, vfat, and so on). Tonight you only read those tags. You do not mount, format, or wipe anything.

Skip until SSH works

If you cannot log in from the couch yet, stop. That is SSH from the couch. Labels 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 room left on a path, that is see if the leftover box still has room (df).

What this is

blkid prints the tags on disk slices: LABEL, UUID, TYPE, and similar fields. In plain English: which stick or slice is which, by name and fixed ID, not only by a device letter that can move. Night one is a look. blkid does not mount, unmount, format, or wipe anything.

Practice: read the tags

SSH in from the couch, then ask:

blkid

You should see one line per slice that has a recognizable filesystem. In plain English:

• LABEL — the friendly name on that slice, if someone set one (often blank on a fresh install).
• UUID — the long fixed ID for that slice. Useful later when a path or fstab line wants a stable name.
• TYPE — the filesystem flavor (ext4, xfs, vfat, exfat, ntfs, and so on).
• The path at the start of the line — usually something like /dev/sda1 or /dev/sdb1.

Match a line to a name you already saw in lsblk. Home-safe look only. Do not format, wipe, or remount anything tonight.

Optional: a table-style list that is easier to scan:

blkid -o list

Same tags, arranged as columns. Still a look.

Optional: ask about one device only (use a name you already saw in lsblk — do not guess):

blkid /dev/sdb1

That prints tags for that one slice. Still no change to the disk. If your stick uses a different letter, swap in the name from lsblk.

Optional: after you plug in a USB for backup

Plug the stick into the leftover box. Run lsblk so you see the device name, then run blkid (or blkid /dev/… for that slice). You should see TYPE and maybe a LABEL that matches the stick you expect. 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 reading labels and IDs.

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

Skip buying a NAS because a label looks unfamiliar. Free room is leftover-box disk-space. Disk names without tags are leftover-box lsblk. Mount maps are leftover-box findmnt.

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 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

Need the disk-name list first? See disks and USB sticks on the leftover box. Need which folders are already attached? See which leftover-box folders are already attached. Need the stable paths under /dev/disk/by-uuid? See stable leftover-box disk names by UUID. 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

• Skip if SSH still fails. Finish SSH from the couch first.
• Skip leftover-box lsblk, leftover-box findmnt, leftover-box disk-space, or total disk size as tonight's job if you only came for labels and UUIDs. Those notes already exist.
• Skip mount/umount as the lesson, and skip rewriting disks, dd, shred, fdisk, parted, and format.
• Skip buying a NAS because a label 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 leftover box on the house network. Do not forward port 22.