From the install doc of TikiWiki:
./setup.sh $USER yourgroup 02777
- Replace yourgroup with your default group.
- NOTE: If you do execute this last command, you will not be able to delete certain files created by Apache. You will need to ask your system administrator to delete them for you, if needed.
Indeed, the files are owned by Apache and a lambda user cannot delete them from shell.
The solution is to delete file from a script runned by Apache: this script is a rough implementation. Could be enhanced a little!
Using that, you may delete your entire site: don't keep it in your public area !
on some hosting site you can move the file you want to delete to the /tmp dir. from there they will be deleted at some point. at least this is an easy way to move stuff out of your quota.
Note: Depending on how the hosting is setup /tmp might in fact be within your quota and your home area, dont rely on this method. - Damian