Secure /tmp is a read-only filesystem

Introduction

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.

Description

When attempting to start or restart a service that requires access to "/tmp" you see the service fail to start or restart, causing a service failure. Other issues such as WHM access or PHP sessions may also encounter errors.

Procedure

Please Note that 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:

   /etc/fstab

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

   /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:"

   /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