Hi,

There are some settings for file system quotas in Web.config, you can copy these into your user.config to override them:

<add key="UserFolderDiskQuotaInMegaBytes" value="300" />
    <add key="MediaFolderDiskQuotaInMegaBytes" value="6000" />
    <add key="AdminDiskQuotaInMegaBytes" value="12000" />
    <add key="UserFolderMaxSizePerFileInMegaBytes" value="10" />
    <add key="MediaFolderMaxSizePerFileInMegaBytes" value="30" />
    <add key="AdminMaxSizePerFileInMegaBytes" value="2000" />
    <add key="UserFolderMaxNumberOfFiles" value="1000" />
    <add key="MediaFolderMaxNumberOfFiles" value="10000" />
    <add key="AdminMaxNumberOfFiles" value="100000" />
    <add key="UserFolderMaxNumberOfFolders" value="50" />
    <add key="MediaFolderMaxNumberOfFolders" value="500" />
    <add key="AdminMaxNumberOfFolders" value="1000" />

However, another common cause of this is that many hosting control panels require you to allocate your disk space to the site. They give you a certain amount of space but they don't allocate all of it to your site, so your site can still run out of space if you don't allocate more of the free disk space to the site. You might look around for settings to allocate the free space in your web hosting panel.

Hope it helps,

Joe