mongodb crashed with the error or permission denied
It's not mongodb fault. Your system went to &quot;read only&quot; mode.
You can see errors on that log file. Positive is that system managed to write that information to log file because it makes easier to debug this problem.

/var/lib/mongo/journal: opendir: Permission denied
couldn't open [/proc/1281/stat] errno:13 Permission denied

Check /var/log/syslog (or /messages) for more info, something fatal happened on that node and it's operating system!