I tried resizing partitions so upgrades are easier, but ran into “telnet connection timed out”. I found a solution on tjc so I’m reposting here for archive purposes.
The relevant part is:
connecting to your device in recovery mode
older Linux (e.g. Debian Jessie): typing ifconfig -a should list a new device usb0 (or a greater number, if you had other usb devices before) configure this device with: dhclient usb0 new Linux (e.g. Debian Stretch): typing ip address list should list a new device without ip-address. In my case: enp0s20u1 configure this device with: dhclient enp0s20u1 type telnet 10.42.66.66 to connect to your SailfishX device
You should now see:
Welcome to the recovery tool!
The available options are:
- Reset device to factory state
- Reboot device
- Perform file system check
- Run sshd
Type the number of the desired action and press [Enter]:
and the tjc link is: [Question] xperia recovery mode? - together.jolla.com