During normal use, my Ubuntu laptop intermittently will encounter some I/O error and then remount
/ as read-only (yes I’ve checked SMART logs, nothing shows up; I’ve also replaced the drive, no luck). The problem is I can never read the underlying original error (if any is reported) because the filesystem is remounted read-only by then, so the error doesn’t get recorded to disk anywhere, and if I run
dmesg the circular buffer has been fully spammed by other processes complaining about read-only filesystem and that’s all that’s visible.
To reiterate, I can’t look through
/var/log because the filesystem has been mounted read-only by then, so
rsyslog failed to record any errors at all.
I also have limited ability to start new tools because the disk subsystem reports generic I/O errors at this point. Only whatever is cache resident is runnable.
The only thing I can think of is turning
/var/log into an in-memory tmpfs and restarting
rsyslog, waiting for the error to happen, and hope I can find it in
/var/log. Maybe even running some standard tools like
less, etc. in a loop so they’ll definitely be available after the disk subsystem fails.
Is there a simpler option?
Here is Solutions:
We have many solutions to this problem, But we recommend you to use the first solution because it is tested & true solution that will 100% work for you.
log_buf_len= kernel parameter via grub to something big like
Note: Use and implement solution 1 because this method fully tested our system.
Thank you 🙂