Written 5 Sep 2026. This is a how-to, not a product card.

Format a USB stick for the house backup

Wipe and format a spare USB stick so the old PC can mount it for the house-folder backup. Ext4 for Linux. This erases the stick. You don't need a NAS.

Only need to see whether the stick already shows up? That look is see if the USB backup disk showed up. Already mounting fine and ready to copy? Jump to a backup of the house folder. This note is for a blank stick, a Windows stick that mounts awkwardly, or a mount that keeps failing until you give the stick one clean Linux filesystem.

Skip until you mean to erase this stick

Formatting deletes everything on the stick. Don't format the computer's system disk. Don't format the only copy of photos you care about. Don't buy a NAS so a stick can get a filesystem. If SSH still fails, fix that first: SSH from the couch.

What this is

One spare USB stick, wiped on purpose, with a single ext4 partition the old PC can mount at /mnt/backup. Ext4 is the usual Linux filesystem. Windows and phones will not open that stick afterward without extra tools. That is fine for a backup stick that lives with this computer. You are not building a boot installer stick (that is make a boot USB for the install). You are not moving the live house share onto USB forever (that is put the house folder on a USB disk).

Step 1: awake, then SSH

Power light. Fan. If it looks asleep, start with is the computer still on?. You need SSH from the couch: SSH from the couch. Connect fails? when SSH won't connect.

Step 2: plug in the spare stick and name the disk

Use a stick you are willing to wipe. Plug it into the computer. Wait a few seconds. List disks:

lsblk -f

Find the new disk whose SIZE matches the stick, often sdb with a partition like sdb1. The computer's own disk is usually the smaller line you installed Debian or Ubuntu on. Wrong disk here wipes the OS. If nothing new appears, try another port or cable, then run the same command again. Fuller look: see if the USB backup disk showed up.

Write down the disk name (sdb) and the partition name (sdb1) from your printout. The examples below use those names. Swap them if yours differ. Never copy sda from a blog if your stick is sdb.

Step 3: unmount if it already mounted

Windows sticks often auto-mount. Unmount the partition first (harmless if it was not mounted):

sudo umount /dev/sdb1

If the stick has no partition line yet, skip this and go to step 4 with the disk name only.

Step 4: one partition, then ext4

This erases the stick. Last chance to unplug the wrong disk.

Make a fresh GPT layout and one partition that fills the stick:

sudo parted /dev/sdb --script mklabel gpt mkpart primary ext4 1MiB 100%

Then format that partition. Label it so you recognize it later:

sudo mkfs.ext4 -L HOUSEBAK /dev/sdb1

Confirm:

lsblk -f

You should see ext4 and the label HOUSEBAK on the USB partition. If parted or mkfs.ext4 is missing, install the usual tools once:

sudo apt update && sudo apt install -y parted e2fsprogs

Then rerun the parted and mkfs lines.

Step 5: mount it and make the backup folder

Mount the formatted partition:

sudo mkdir -p /mnt/backup && sudo mount /dev/sdb1 /mnt/backup

Confirm the mount stuck (prints a line if it did):

findmnt /mnt/backup

Make a landing folder your user can write:

sudo mkdir -p /mnt/backup/share && sudo chown "$USER:$USER" /mnt/backup/share

Optional check that the label matches:

findmnt -no LABEL /mnt/backup

Step 6: copy the house folder (or stop here)

Haven't made the share yet? That is a file share, not a format problem. When the house folder exists (often /srv/share), the copy itself is a backup of the house folder:

rsync -a /srv/share/ /mnt/backup/share/

Then confirm files landed: check that the backup actually copied. Unmount before you yank the cable:

sudo umount /mnt/backup

Mount fails next week, or rsync complains? When the house backup won't run.

What this is not

This is not a bootable Ubuntu installer stick. It is not exFAT so a Windows laptop can browse the backup (pick ext4 for a Linux-only house backup). It is not RAID. It is not a reason to buy a NAS tonight. It is not formatting the system disk. It is not leaving the only photo copy on a stick you are about to wipe.

What next

Run the copy: a backup of the house folder. Confirm it landed: check that the backup actually copied. Pull one file back sometime: restore one file from the USB backup. Prefer another old PC instead of a stick: copy the house folder to another old computer. Stick still missing after you plug it in: see if the USB backup disk showed up.

Skip

• Skip if you are not willing to erase this stick.
• Skip formatting the system disk. Match SIZE in lsblk to the stick first.
• Skip buying a NAS so a stick can get a filesystem.
• Skip the installer-stick walk. That is make a boot USB for the install.
• Skip if you only needed a look. That is see if the USB backup disk showed up.
• Skip cloud backup until a plain second copy exists on a stick or another old PC.