First off, use of strace (and installing additional software to Gaia in general) is not officially supported. Use at your own risk. That said, to install strace on a 2.6.18 kernel Gaia system:
1) Download the rpm from here: http://vault.centos.org/3.8/os/i386/RedHat/RPMS/strace-4.5.14-0.EL3.1.i386.rpm
2) Copy it to the firewall via SCP.
3) Install it with this command: rpm -Uhv --force strace-4.5.14-0.EL3.1.i386.rpm
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