Installation/uninstallation fails if /tmp is mounted with noexec option

Products

• VMware Smart Assurance

Issue/Introduction

• NCM installation/uninstallation fails if /tmp is mounted with noexec option or has no enough disk space.
• Install and debug log will not have errors logged pointing to /tmp permission.
• NCM installation fails with error 'perl is required for this installation and must be in the system PATH' after running the install.sh script, where in the prerequisite check is successful meaning perl is already installed in the system.
• Error '/etc/voyence.conf: No such file or directory' is observed during the installation.

Environment

NCM - 10.1.x

Cause

Enabled debug on installer with steps from KB: Enable debug on the 10.1.x VSA installation executable

From the debug output noticed that installer creates a executable file in /tmp and the file execution from /tmp directory was failing.
Error in debug output -
Command.run(): Cannot run program "/tmp/656396.tmp/executeScriptTmp": error=13, Permission denied

/tmp directory has 777 permissions with root user as owner, which indicates /tmp directory has full permissions.

After the above error message, installer probes below:
Error
-----
Prerequisite check failed
ERROR: perl is required for this installation and must be in the system PATH.

PRESS <ENTER> TO ACCEPT THE FOLLOWING (OK):

Before pressing enter, take another SSH session to the VM where NCM installer is executed. Check the content of the file at the path in error.

In this case, content of the file /tmp/656396.tmp/executeScriptTmp is below:
#!/bin/bash
perl -v

Navigate to /tmp/656396.tmp/ and type ./executeScriptTmp
This would fail, which indicates that the /tmp filesystem doesn't have execute access.

It is recommended to mount /tmp with exec option as installer creates iatemp file during installation and uninstallation which runs from /tmp directory per install.sh script.

Resolution

It is advised for users to mount /tmp with exec option.
If user is not ready to enable execute permission, due to security reason or to adhere with security compliance policy; export below command before starting the installer for both installation and uninstallation.

• export IATEMPDIR=<Directory Name which has exec permission or has enough disk space>
  Example:
  export IATEMPDIR=/opt
  here
  /opt is mounted with exec permission and has enough diskspace
  
  
• Now run one of the below based on the use case:
  • for NCM installation
    ./install.sh -i console

    
  • for NCM uninstallation.
    $VOYENCE_HOME/software/Uninstall_Core/Uninstall_VMware_Smart_Assurance_Network_Configuration_Manager
    

Note: Check mount details of /tmp by running cat /etc/fstab in linux server where NCM installation fails.
Sample output:
#
# /etc/fstab
# Created by anaconda on Thu Feb  3 09:44:55 2022 

/dev/mapper/vg_root-lv_tmp /tmp                    ext4    defaults,nodev,nosuid,noexec        1 2