Support

1. Akeeba Backup 3.11.2 uses the official Dropbox API which does support deletions, therefore quota managements. As a result you can use Dropbox with the remote quotas feature of Akeeba Backup.

2. No, there is a single quotas setting which is applied both locally and remotely. In fact, you should note that by default the local files are automatically deleted once uploaded to Dropbox. If you want to keep them on your server you need to uncheck the "delete after upload" checkbox in the Upload to Dropbox configuration. I recommend deleting the backups from your server and keeping them in Dropbox. Should you need to restore your site you can always transfer the archive files back to your site using the Manage Backups page.

i'm afriad that somthing will go wrong with the upload and i will not have the backup files (because i delete locall).

I think you are not clear on how the automatic deletion works. Only after all parts of the backup archive have been successfully uploaded to remote storage will Akeeba Backup delete the local copies. This is the paranoid way to implement this feature. When we're talking about backups being paranoid always pays off so that's what we implemented.

does "Checking for failed backups" script inform you (mail or something like that) when upload to dropbox failed?

No. It will only notified you of failed backups. Backups which completed successfully but did not success at uploading the files are not reported. They are successful backups and the backup archive is still on your server. As I said, a failed upload will NOT result in local backup archives being deleted.

You are always notified in the Akeeba Backup control panel and Manage Backup pages about failed backups.

If you have created a CRON job with the CLI failed backup check script you are also notified by email.

If you have published the Quick Icon - Akeeba Backup Notification plugin (enabled by default) you are also notified in your Joomla! control panel page, the page you see when you log in to your site's back-end.