Solaris Common Messages and Troubleshooting Guide

setmnt: Cannot open /etc/mnttab for writing

Cause

The system is having problems writing to /etc/mnttab. The filesystem containing /etc may be mounted read-only, or is not mounted at all.

Action

Check that this file exists and is writable by root. If so, ensure that the /etc filesystem has been mounted, and is mounted read-write rather than read-only.