FTP 150 File Status OK vs 450 File Action Not Taken
FTP 150 (File Status OK) is a 1xx Positive Preliminary response, while 450 (File Action Not Taken) is a 4xx Transient Negative response. 150 indicates that the file status is okay and the server is about to open the data connection for the transfer. This is the normal precursor to a file transfer. 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 file status is okay and the server is about to open the data connection for the transfer. This is the normal precursor to a file transfer.
When You See It
Right before a file download or upload begins, confirming the file is accessible and the data channel is being opened.
How to Fix
No fix needed — this means the transfer is about to start. If the transfer stalls after this reply, check firewall rules blocking the data connection.
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
150 is a 1xx Positive Preliminary response, while 450 is a 4xx Transient Negative response.
FTP 150: The file status is okay and the server is about to open the data connection for the transfer. This is the normal precursor to a file transfer.
FTP 450: Requested file action not taken. The file is unavailable due to being busy, locked by another process, or temporarily inaccessible.
You encounter 150 when right before a file download or upload begins, confirming the file is accessible and the data channel is being opened.
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 150 (File Status OK): No fix needed — this means the transfer is about to start. If the transfer stalls after this reply, check firewall rules blocking the data connection. 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.