FTP 110 Restart Marker Reply vs 450 File Action Not Taken
FTP 110 (Restart Marker Reply) is a 1xx Positive Preliminary response, while 450 (File Action Not Taken) is a 4xx Transient Negative response. 110 indicates that the server is sending a restart marker reply. The text is exact and not left to interpretation. This marker is used to indicate the point at which a file transfer should be restarted. In contrast, 450 means that requested file action not taken. The file is unavailable due to being busy, locked by another process, or temporarily inaccessible.
Description
The server is sending a restart marker reply. The text is exact and not left to interpretation. This marker is used to indicate the point at which a file transfer should be restarted.
When You See It
During a resumed file transfer when the server confirms the restart position in the data stream.
How to Fix
No fix needed — this is a normal response during transfer recovery. If restarts keep failing, verify the marker format matches what your client expects.
Description
Requested file action not taken. The file is unavailable due to being busy, locked by another process, or temporarily inaccessible.
When You See It
When you try to access a file that is locked by another user or process, or when the server temporarily cannot process the file.
How to Fix
Wait and retry the operation — the file may be locked by another transfer. If persistent, check server-side file locks and permissions.
Key Differences
110 is a 1xx Positive Preliminary response, while 450 is a 4xx Transient Negative response.
FTP 110: The server is sending a restart marker reply. The text is exact and not left to interpretation. This marker is used to indicate the point at which a file transfer should be restarted.
FTP 450: Requested file action not taken. The file is unavailable due to being busy, locked by another process, or temporarily inaccessible.
You encounter 110 when during a resumed file transfer when the server confirms the restart position in the data stream.
You encounter 450 when when you try to access a file that is locked by another user or process, or when the server temporarily cannot process the file.
When to Use Which
For 110 (Restart Marker Reply): No fix needed — this is a normal response during transfer recovery. If restarts keep failing, verify the marker format matches what your client expects. For 450 (File Action Not Taken): Wait and retry the operation — the file may be locked by another transfer. If persistent, check server-side file locks and permissions.