Fileshare: "The uploaded file failed to write to disk."

Hello Everyone,

First, I am newbie to CMS concept and never involved in website management either. anyway, this week i was dumped with admin access and told to create some web-pages and a new file sharing system for our project on a already existing Drupal CMS.

It was easy and i managed everything in 2 hours, and fileshare system was up and running for day one, the next day mails started popping into my Inbox, SUBJECT: cannot upload files and the following Error "The uploaded file failed to write to disk." error 7 in the fileshare module.

My first attempt was to increase the Quota for the user and per upload file size, it didn't work. Now i doubt that the folder on the server has no space left. There are also many other file shares created on this system and I do not have access to the server to check that.

My question are:

1) By default, where are the uploaded files for file-share system stored? is it under Drupal installation, can we change the destination folder to somewhere else i.e on a another network server, of course with writable permission.
2) is it possible to manage different destination folder for each file-share created.
3) Can i do all this with out requesting for server access. remember only admin access.

additional info
The file size are small, so no problem with php.ini either
The file are uploaded via Drupal (Private).

Any help is highly appreciated!!