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Reading Serv-U's Log File  -  KB Article #1212

Related Articles --

The Serv-U log will indicate what kind of message is being displayed by either a number at the beginning of the log when logging to a file, or when viewing the Serv-U Log Screen. When viewing the Serv-U log screen the type of message with be color coded. Below is a legend describing each message type and corresponding color.

Below is a listing of the types of messages by the number displayed in brackets that also correspond to each color in the above legend.

[1] - System Messages (Green)
[2] - Security Messages (Blue)
[3] - IP Names (Orange)
[4] - ODBC Calls (Purple)
[5] - ODBC Errors (Red background)
[10] - Downloads (Grey Background)
[11] - Uploads (Grey Background)
[12] - File Deletions (Grey Background)
[13] - File and Directory Renames (Grey Background)
[14] - Directory Creations (Grey Background)
[15] - Directory Deletions (Grey Background)
[20] - FTP Commands (Yellow Background)
[21] - FTP Replies (Yellow Background)
[30] - SSH Commands (Orange Background)
[31] - SSH Replies (Orange Background)
[40] - HTTP Commands (Blue Background)
[41] - HTTP Replies (Blue Background)

Below is a copy of Serv-U's log for a typical connection and upload. The log has been broken down into several different sections and explained.

[1] Fri 03Jan03 09:13:20 - Starting FTP Server...
[1] Fri 03Jan03 09:13:20 - FTP Server listening on port number 21, IP

This is Serv-U confirming that it is listening on port 21 on the IP Address If you see any errors here the FTP client will not be able to connect. Two very common errors are "Port 21 in Use" and "Trying to listen on non-existent IP Address". There are separate knowledge base articles to address each of these.

For the purpose of this knowledge base the first two sections of each line entry have been removed. This information simply dictates the time and date when activity is occurring.

Connected to (Local address
220 Serv-U FTP Server v4.2 for WinSock ready...

The first thing Serv-U does when an FTP client logs in is introduce itself. This is the Server ID tag. For security reasons some FTP Admins like to customize this Server ID tag so the actual server name is hidden. Knowledge Base article 1206 will walk you through customizing this.

WARNING: Some FTP clients (like FTP Voyager) rely on this Server ID tag to identify the server.

USER test
331 User name okay, need password.
PASS xxxxx
User TEST logged in
230 User logged in, proceed.

Any time an FTP client logs into Serv-U a user name and password will have to be sent from the client and be approved by Serv-U. Above you see a correct user name and password being sent to Serv-U.

211-Extension supported
211 End

The FEAT command ( short for Feature ) is the FTP client's way of asking the server if it supports anything special. The server then responds with any unique commands it supports.

REST 100
350 Restarting at 100. Send STORE or RETRIEVE.
350 Restarting at 100. Send STORE or RETRIEVE. REST 0
350 Restarting at 0. Send STORE or RETRIEVE.
257 "/c:" is current directory.
CWD /c:
250 Directory changed to /c:

Here the FTP client is navigating to the home directory assigned by Serv-U. This particular user's home directory is C:\.

200 Type set to A.
227 Entering Passive Mode (127,0,0,1,4,122)

In order for the FTP client to see what is in the home directory a data connection has to be established. There are two different methods for this to happen, PASV and PORT. For a breakdown of the differences please review Knowledge Base article 1138.

150 Opening ASCII mode data connection for /bin/ls.
226 Transfer complete.

After we see the "226 Transfer complete" message we know that the data connection was successfully established. The client should now be able to see the files in their home directory.


In this part of the log the FTP client has started uploading a file. The command used to do this is STOR and the file being uploaded is called DCP00618.JPG.

Receiving file c:\dcp00618.jpg

This is the server confirming that the file is being received.

150 Opening BINARY mode data connection for DCP00618.JPG.
Received file c:\dcp00618.jpg successfully (6026 Kb/sec - 234469 bytes)
226 Transfer complete.

Finally, the server confirms that the transfer is complete.

MDTM 20021206160948 /c:/DCP00618.JPG
253 Date/time changed okay.

This is one of the additional features (displayed in the FEAT reply) that Serv-U supports. This particular feature allows the time stamp on the file to remain the same when the file is uploaded. In most cases, whenever a file is uploaded to the FTP server it is given a new time stamp.

221 Goodbye!
Closing connection for user TEST (00:00:01 connected)

This is the user disconnecting from the server.