TOPIC:

ok I think I've got it..

When I tried to export a 277MB project = it worked
401 MB project = failed
zapped the failed zip in /tmp
removed the content and went back to the 277MB project and export worked

so I think I'm running out of space on /tmp

Where can I set the directory to create the zip?

Hmmm. Xerete uses ZipArchive, and that uses sys_get_temp_dir().

So that's not going to be that easy.

I just dropped

putenv('TMPDIR=/data/xerte');

into modules/xerte/export.php

and hey presto
2015-10-12 10:14:55 /srv/www/vhosts/xerte/xertetoolkits/modules/xerte/export.php112Temporary zip file is : /tmp/xerteExportFEdO0Y
went to
2015-10-12 10:27:35 /srv/www/vhosts/xerte/xertetoolkits/modules/xerte/export.php112Temporary zip file is : /data/xerte/xerteExport793mcg

however the change of TMPDIR does not appear to be set in env

# env | grep TMP
# env | grep TMPDIR

For future releases would it be possible to make the directory where the zip is created a variable that can be configured via the admin UI