SSH into your ADC with your terminal emulator of choice, then enter the shell prompt and execute the following lines to clear space for upgrades.
cd /
rm -rf /var/nstrace/*
rm -rf /var/log/*
rm -rf /var/nslog/*
rm -rf /var/tmp/support/*
rm -rf /var/core/*
rm -rf /var/crash/*
rm -rf /var/nsinstall/*
The tipps have been very helpful for me when i was seaching online a solution on what to delete on my Netscaler, because i was not able to upgrade due to lack of enough space on the appliance. Thanks very much.
Glad to help.