I noticed oracle file system /opt/oracle got unmounted for some reason
i checked the storage and there is no issue at the storage level. no path failed.
system was up last one month.
i tried to do mount -a didn't work.
i was able to mount manually
mount /opt/oracle and it read /etc/fstab entry and mounted.
usually if there is any issue with the file system it goes to read only mode.
trying to find out why it was unmounted.