I installed Fedora Silverblue on my PC last Friday. Today there was a power outage - I don’t know if it has anything to do with my problem but the fact is that after turning on computer again I can’t mount my second disk anymore.
What file system is on that partition.? If ext4 then one can use fsck with a command like sudo e2fsck /dev/sdb1 to make an attempt to repair it.
The system usually will not mount a file system that is marked as ‘dirty’ meaning there is something wrong with the way it was disconnected and that must be repaired before it can be mounted again.
One may need to use different options or if it is not an ext4 file system then other commands may be required.
That would be done with fsck.ntfs so my suggestion above would be changed to read sudo fsck.ntfs /dev/sdb1 and could include the -V -N options for the first run to see in verbose mode what would be done before actually doing the fix.
Finally I was able to fix it with sudo ntfsfix /dev/sdb1:
Mounting volume… $MFTMirr does not match $MFT (record 3).
FAILED
Attempting to correct errors…
Processing $MFT and $MFTMirr…
Reading $MFT… OK
Reading $MFTMirr… OK
Comparing $MFTMirr to $MFT… FAILED
Correcting differences in $MFTMirr record 3…OK
Processing of $MFT and $MFTMirr completed successfully.
Setting required flags on partition… OK
Going to empty the journal ($LogFile)… OK
Checking the alternate boot sector… OK
NTFS volume version is 3.1.
NTFS partition /dev/sdb1 was processed successfully.