Transfer ratios and quotas are just one of the many ways in which file transfers are managed on the Serv-U File Server. The following sections provide information about their usage.
Transfer ratios are a convenient way of encouraging file sharing on your file server. By specifying an appropriate transfer ratio setting, you can grant credits to the user for transferring a specified number of bytes or complete files. This is commonly used to grant a user the ability to download 'x' megabytes of data or files for every 'y' megabytes of data or files that they upload.
To enable transfer ratios for the current user account, click Ratios & Quotas on the User Information page of the User Properties window, and then select Enable transfer ratio. Select the appropriate type of ratio to impose on the user account. Ratios can be tracked in terms of megabytes or complete files. They can also be tracked per session established or for all sessions established by the user account.
The ratio itself is configured by assigning a numeric value to both the uploads and downloads side of the ratio. For example, a 3:1 ratio that is counting files over all sessions means that the user account must upload three files in order to have the ability to download one file. The current credit for the user account is displayed in the Credit field. This value is the current value and can be initialized to a non-zero value to grant the user initial credits.
Quotas are another way to limit the amount of data that is transferred by a user account. When a Maximum quota value is assigned to the user, they are not able to use more disk space than that value. The Current field shows how much disk space is currently being used by the user account. When initially configuring a quota, both fields must be filled in. From that point on, Serv-U tracks the file uploads and deletions made by the user and updates the current value as appropriate.
A considerable drawback to using quotas is that in order for the current value to remain accurate, changes must not be made to the contents of the directories that are accessible by the user account outside of Serv-U. Because these changes take place outside of a file server connection, Serv-U cannot track them and update the current quota value. As an alternative to quotas, consider imposing a maximum size on the contents of a directory when specifying the directory access rules for the user account. For more information about this option, see Directory access rules.
Files listed in the ratio free file list are exempt from any imposed transfer ratios. In other words, if a user must upload files in order to earn credits towards downloading a file, a file that matches an entry in this list can always be downloaded by users, even if they have no current credits. This is commonly used to make special files, such as a readme or a directory information file, always accessible to users.
You can use the
? wildcard characters when you specify a ratio free file. Using
* specifies a wildcard of any kind of character and any length. For example, entering
*.txt makes any file with a
.txt extension free for download, regardless of the actual filename. You can use a
? to represent a single character within the file name or directory. You can also specify full paths by using standard directory paths such as
C:\ftproot\common\ (on Windows) or
/var/ftpfiles/shared/ (on Linux).
In addition, you can use full or relative paths when you are specifying an entry. If you use a full path when you specify a file name, only that specific file is exempt from transfer ratios. If you use a relative path, such as when you enter just
readme.txt, the provided file is exempt from transfer ratios regardless of the directory it is located in.