How to install SugarCRM with PHP safe_mode = on?

Adjust permissions so that the web server (running as www-data) can read and write what it wants:

chmod -R 777 cache/;
chmod 777 custom/;
chmod 777 data/;
chmod 777 data/upload/;
chmod -R 777 modules/;

If auto-checking for update is enabled and also SAFE_MODE, use this workaround to prevent SugarCRM to create that directory with www-data:www-data ownerhip:

mkdir cache/upload/upgrades/;
chown matthias:psacln cache/upload/upgrades/;
chmod a+w cache/upload/upgrades/;