Comment 3 for bug 1857649

Checking through the Syslog, IO errors are repetitive. Because of numerous IO errors the file system flips to RO to protect any data on it.

Dec 26 23:26:00 ubuntu kernel: [ 8.716013] EXT4-fs warning (device sda1): ext4_clear_journal_err:5115: Filesystem error recorded from previous mount: IO failure
..
Dec 26 23:59:01 ubuntu kernel: [ 2003.111196] blk_update_request: I/O error, dev sda, sector 9393041 op 0x0:(READ) flags 0x3000 phys_seg 1 prio class 0

I would check your hardware's health (using your drives SMART capabilities etc), then once corrected, try again.

If you need help, you could try the support forum of your local Ubuntu community http://loco.ubuntu.com/ or asking at https://askubuntu.com or https://ubuntuforums.org, or for more support options please look at https://discourse.ubuntu.com/t/community-support/709