This article provides solution to the upgrade problem for MX series devices where the image installation from 13 to 16 fails with the config.tar.gz message .

NOTICE: uncommitted changes have been saved in /var/db/config/juniper.conf.pre-install
tar: memory exhausted
WARNING: Backup of configuration files failed
ERROR: insufficient space for config.tar.gz
ERROR: junos-install fails post-install
Installation failed for package '/var/tmp/junos-install-mx-x86-64-16.1R4-S12.1.tgz'

Following error seen while running the command "request system software add <image>"

request system software add /var/tmp/junos-install-mx-x86-64-16.1R4-S12.1.tgz no-validate reboot 
Installing package '/var/tmp/junos-install-mx-x86-64-16.1R4-S12.1.tgz' ...
Verified manifest signed by PackageProductionEc_2018
Verified manifest signed by PackageProductionRSA_2018
Verified manifest signed by PackageProductionRSA_2018
Verified contents/junos-daemons.tgz
Verified contents/junos-runtime-mx.tgz

>Output trimmed< 

camcontrol: not found
camcontrol: not found
camcontrol: not found
Verified manifest signed by PackageProductionEc_2018
Saving the config files ...
NOTICE: uncommitted changes have been saved in /var/db/config/juniper.conf.pre-install
tar: memory exhausted

WARNING: Backup of configuration files failed

WARNING: This installation attempt will be aborted.
WARNING: If you wish to force the installation despite these warnings
WARNING: you may use the 'force' option on the command line.
ERROR: insufficient space for config.tar.gz
ERROR: junos-install fails post-install
Installation failed for package '/var/tmp/junos-install-mx-x86-64-16.1R4-S12.1.tgz'

The error observed is when there is insufficient available space to extract the config.tar.gz file but could also be due to corrupted file system. 

1. Run the show system storage and check available space . Then use request system storage cleanup command to clear space on the box . In customer box even after clearing the space for /var/tmp we faced same issue again. 

     request system storage cleanup

      List of files to delete:

       Size Date         Name

 2B Dec  2  2022 /var/crash/bounds

 574B Dec  2  2022 /var/crash/info.0

 23.0M Dec  2  2022 /var/crash/kernel.0

 1127.7M Dec  2  2022 /var/crash/vmcore.0

 180.9K Jul 31 17:38 /var/log/chassisd.0.gz

 174.3K May 22  2023 /var/log/chassisd.1.gz

 170.1K Apr 21  2022 /var/log/chassisd.2.gz

 176.3K Aug  7  2020 /var/log/chassisd.3.gz

 547.9K Oct 29 05:21 /var/log/cli-commands.0.gz

 645.7K Jul 25 03:45 /var/log/cli-commands.1.gz

..

..

request system software add /var/tmp/junos-install-mx-x86-64-16.1R4-S12.1.tgz no-validate reboot force

Oct 29 05:34:25

Installing package '/var/tmp/junos-install-mx-x86-64-16.1R4-S12.1.tgz' ...

Verified manifest signed by PackageProductionEc_2018

Verified manifest signed by PackageProductionRSA_2018

Verified manifest signed by PackageProductionRSA_2018
..
..
Verified manifest signed by PackageProductionEc_2018

Saving the config files ...

NOTICE: uncommitted changes have been saved in /var/db/config/juniper.conf.pre-install

tar: memory exhausted

WARNING: Backup of configuration files failed

ERROR: insufficient space for config.tar.gz

ERROR: junos-install fails post-install

Installation failed for package '/var/tmp/junos-install-mx-x86-64-16.1R4-S12.1.tgz

2.  As the above steps doesn't help we then suspected file system related issue. To clear the same we performed a commit synchronize full force on the box first to clear any file system related issues . 

3. Next, we decided to perform a step upgrade . We went to 14 first by using request system software add /var/tmp/<image> force no-validate reboot. 

request system software add /var/tmp/<image no-validate force  reboot            

Installing package '/var/tmp/jinstall64-14.2R5-S2.1-domestic-signed.tgz' ...

Verified jinstall64-14.2R5-S2.1-domestic.tgz signed by PackageProductionEc_2016

Verified jinstall64-14.2R5-S2.1-domestic.tgz signed by PackageProductionRSA_2016

Adding jinstall64...

Verified manifest signed by PackageProductionEc_2016

WARNING:     This package will load JUNOS 14.2R5-S2.1 software.

WARNING:     It will save JUNOS configuration files, and SSH keys

WARNING:     (if configured), but erase all other files and information

WARNING:     stored on this machine.  It will attempt to preserve dumps

WARNING:     and log files, but this can not be guaranteed.  This is the

WARNING:     pre-installation stage and all the software is loaded when

WARNING:     you reboot the system.

Saving the config files ...

NOTICE: uncommitted changes have been saved in /var/db/config/juniper.conf.pre-install

tar: memory exhausted

WARNING: Backup of configuration files failed

Installing the bootstrap installer ...

WARNING:     A REBOOT IS REQUIRED TO LOAD THIS SOFTWARE CORRECTLY. Use the

WARNING:     'request system reboot' command when software installation is

WARNING:     complete. To abort the installation, do not reboot your system,

WARNING:     instead use the 'request system software delete jinstall'

WARNING:     command as soon as this operation completes.

Saving package file in /var/sw/pkg/jinstall64-14.2R5-S2.1-domestic-signed.tgz ...

Saving state for rollback ...

request system reboot at now 

Reboot the system at now? [yes,no] (no) yes

System going down IMMEDIATELY