Wipeout

I recently decided to go through some old PCs and hard disks (yes, actual spinning bits of metal) and recycle or simply junk them. I figured I should wipe them properly first, and given that they had been installed with a range of OSs, setup a bootable USB stick so that I could boot and wipe in one easy motion.

• Download Alpine Linux 3.8.1 ISO – I had only x86_64 machines, YMMV obviously
• Write this to a USB stick using dd (on Linux), or Balena Etcher on Windows
• Insert the stick and boot the machine after making any necessary BIOS changes
• If the machine has been unbooted for too long or (as one of mine) has a flat CMOS clock battery so cannot retain time across reboots, set the time
  • manually: date --set="20181217"
  • automatically: setup-alpine to start configuring things, then CTRL-C after network setup, and execute setup-ntp
• Then setup-alpine; apk add coreutils
• Finally, shred --verbose /dev/sdXN where X is the device id and N the partition number (eg., /dev/sda2), or shred --verbose -n1 /dev/sdXN if you’re using a modern disk (apparently) and only want one pass of random data

Installing Alpine

After installing Alpine as above:

• adduser mort
• create ~mort/.ssh/authorized_keys containing you preferred public key, and set permissions (chmod 600 ~mort/.ssh/authorized_keys)
• apk add sudo and then visudo to allow members of group sudo to sudo
• add mort to group sudo
• logout and then back in

You can then configure storage as you see fit; it seems I once did probably using sudo:

apk add lvm2 git bash xfsprogs
pvcreate /dev/sd[bc] # create persistent volumes group
vgextend vg0 /dev/sdb # assign storage devices to volume group
vgextend vg0 /dev/sdc #
lvcreate --name lv_home --size 60G vg0 # create logical volume `lv_home`
mkfs.xfs /dev/vg0/lv_home # format `lv_home` using XFS
lvcreate --name lv_backup --size 60G vg0 # create logical volume `lv_backup`
mkfs.xfs /dev/vg0/lv_backup # format `lv_backup` using XFS

# create `/etc/fstab` to match the above configuration
cat >>/etc/fstab <<EOF
/dev/vg0/lv_home	/home	xfs	defaults	0 0
/dev/vg0/lv_backup	/backup	xfs	defaults	0 0
EOF
mount -a -v # mount everything, verbosely