Secure /tmp is a read-only filesystem

Symptoms

When attempting to restart a service or write to the system, you encounter a read-only filesystem error. After reviewing the server, you determine /tmp is read-only.

Cause

The /tmp mount has become corrupted and been mounted as read-only to prevent further errors.

Resolution

Warning: Working with file systems can be a dangerous task. An experienced System Administrator should perform the steps below to minimize risk of damage to your server or file systems.

1. Start by disabling /tmp from your fstab. As root, open the following file with a command line text editor:

   CONFIG_TEXT: /etc/fstab

2. Search for the entries that match /tmp and /var/tmp, which should look something like this:

   CONFIG_TEXT: /usr/tmpDSK     /tmp            ext4    defaults          0 0
   /tmp            /var/tmp        ext4    defaults,bind     0 0

3. Edit the entries for /tmp and /var/tmp to add the noauto flag alongside the other flags, in the column with defaults:

   CONFIG_TEXT: /usr/tmpDSK     /tmp            ext4    defaults,noauto          0 0
   /tmp            /var/tmp        ext4    defaults,bind,noauto     0 0

4. Disable the securetmp service:

   # systemctl disable securetmp

5. Reboot the server.

6. Once the server comes back up, remove the old tmpDSK file:

   # mv -v /usr/tmpDSK{,.$( date +%Y%m%d )}

7. Run securetmp to regenerate the tmpDSK file. Enter y at the prompts to confirm, enable and configure the boot option:

   # /scripts/securetmp

8. Reboot the server once more to remount the /tmp partition.

Additional Resources

Identifying Disk Corruption and Filesystem Errors