Service down due to root partition mounted as read-only

Symptoms

Services are down and cannot be restarted. Attempting to create new files or folders on the root filesystem (/) fail with a message similar to the following.

[root@server ~]cPs# touch /test
touch: cannot touch ‘/test’: Read-only file system

Description 

The root filesystem (/) needs to be read-write for services to start.

Workaround

In some cases, / can be remounted as read-write without needing to reboot the server. The following article explains how to remount a filesystem as read-write.

How to remount a filesystem as Read-Write

In most cases, the / is mounted as read-only due to filesystem errors. You should work with your system administrator to correct the filesystem errors. This usually involves booting the server into a rescue environment and running fsck or xfs-repair. Depending on the severity of the filesystem errors, the file system check run at boot may be sufficient to correct the filesystem errors.

How can I determine a problem is due to File System Errors?