Backup Giving Errors And Not Scheduling

I have used BackupWordpress on my hosted WP sites and it’s the BEST by far, however I am having problems trying to get it to run on a site that is hosted on an IBM iSeries running Zend Server (should be like Apache on AIX).

When I click on the Settings/Backups link I get the following in the Apache error log (but no date/time etc):

sh: whoami: not found
sh: whoami: not found
sh: whoami: not found
sh: groups: not found
sh: groups: not found
sh: groups: not found
sh: whoami: not found
sh: groups: not found

If I update the backup Settings I get:

sh: whoami: not found
sh: whoami: not found
sh: whoami: not found
sh: groups: not found

I also get a file “.backup_warnings” created in the backups folder, it’s content is:

{“php”:{“7a8a67a97cf19a56925a5cf738eef4a7″:”Undefined offset: 0, \/www\/zendsvr\/htdocs\/news\/wp-includes\/capabilities.php, 1106”}}

The scheduled backups are not firing (to my knowledge). I see no logs or errors.

If I manually run the backup I get a modal with the following:

Your backup completed but with the following errors / warnings, it’s probably ok to ignore these.
Here’s the response from the server:
sh: mysqldump: not found
sh: zip: not found

It does create a valid backup, but will not email it to me (it’s only 300kb so not too large), and .backup_warnings is updated to show:

{“mysqldump”:{“7aae56d420a6b753d1d92c508d49f2ee”:”sh: mysqldump: not found\n”}}

I’m not sure if this is because of a fault in our setup or if we can’t use BackupWordpress on an iSeries. Hopefully these errors make some kind of sense. I am willing to try and suggestions to help fix this.

https://wordpress.org/plugins/backupwordpress/