Tcube:
You have two workarounds to limit upload.
1. If you want disallow upload if a folder uses more than xxxxxxx bytes, you can use a macro-condition to disable the unload-button comparing your maximum-value with %total-size%(or %total-bytes%, %total-kbytes%)
-> {.if|{.>|maximum-value|%total-bytes%|.}| ...display the uploadlink .. .}
2. If you want to disallow upload if there is less than xxxxxx bytes on disk available, you can use another macro:
-->{.if|{.<|minimum-available|%disk-free%|.}| ...display the uploadlink .. .}
The only problem with this is, that you have no control about the filesize of files to be uploaded in the uploadform, so you must assign a topvalue high enough to allow normal upload:
If you expect people to upload files of about nnnMBytes, you must have a free-space at least the-number-of-files in your upload-form multiplied by nnnMbytes. If you expect big files, use an upload-form that allows only 1 file at time.