lftp error (550 The volume is too fragmented to complete this operation)

I wrote a bash script to backup my server every day and then lftp the file to another server. I get the following error every few days on some of my servers.

This error did not occur on the first file until now, and the first file was sent without any problem. To send the second file, lftp shows this error in debug.

    <--- 550 The volume is too fragmented to complete this operation.
    ---- Closing data socket
    ---> QUIT
    ---- Closing control socket

--- current lftp configuration settings ---
    set ftp:passive-mode true
    set ftp:prefer-epsv false
    set ftp:sync-mode/ftp.idsoftware.com on
    set ftp:sync-mode/ftp.microsoft.com on
    set ftp:sync-mode/sunsolve.sun.com on
    set ftp:use-allo false
    set ftp:use-tvfs true
    set net:limit-rate 62500000:62500000
    set net:timeout 3600
    set xfer:max-redirections 10

The problem is not from lftp, and the server disk that you send your files to is very fragmented My suggestion is to defragment the drive you want with the Windows Task Scheduler every day and see if you get this problem again.