The error was caused by
[ 25.824555] Aborting journal on device sda2-8.
[ 25.837115] EXT4-fs error (device sda2): ext4_journal_start_sb: Detected aborted journal
[ 25.837124] EXT4-fs (sda2): Remounting filesystem read-only
[ 25.997467] EXT4-fs (sda2): Remounting filesystem read-only
You have a problem with your hardrive which has been mounted readonly. Please fix it and try performing the upgrade again. I'm closing this report because it's not a bug with Ubuntu.
Thanks for your report.
The error was caused by start_sb: Detected aborted journal
[ 25.824555] Aborting journal on device sda2-8.
[ 25.837115] EXT4-fs error (device sda2): ext4_journal_
[ 25.837124] EXT4-fs (sda2): Remounting filesystem read-only
[ 25.997467] EXT4-fs (sda2): Remounting filesystem read-only
You have a problem with your hardrive which has been mounted readonly. Please fix it and try performing the upgrade again. I'm closing this report because it's not a bug with Ubuntu.
Don't hesitate to submit any new bug.