On October 19, 2021, we have enabled single-sign-on for our Plesk Support Center to provide a seamless login/account experience. This implies that you’ll be able to use a single account across any of our web-facing properties.
If you had already registered your account at Plesk 360 (formerly known as My Plesk) please use one for login. Otherwise please re-register it using the same email address as your existing Zendesk login (support account). It’s essential that you use the same email address on our support center to ensure that your tickets stay attached to the same account.

Articles in this section

See more

Backup to remote FTP server fails: Curl error: Unable to resume an interrupted upload: (55) Failed sending data to the peer

Avatar
George Alibegashvili
Updated
Follow
Plesk for Windows Plesk for Linux kb: technical ABT: Group A

Applicable to:

  • Plesk for Linux
  • Plesk for Windows

Symptoms

  • Backup to remote FTP server fails with the error:

    CONFIG_TEXT: Error: server "server"
    Curl error: Unable to resume an interrupted upload: (55) Failed sending data to the peer: Last FTP request: APPE backup_1801300838.zip: Last FTP response: 150 Opening BINARY mode data connection for backup_1801300838.zip: Connection to the FTP server has lost

    CONFIG_TEXT: Unable to create remote backup. Error: Unable to export backup: Curl error: Unable to resume an interrupted upload: (55) Failed sending data to the peer: Last FTP request: APPE backup_2008150549.tar: Last FTP response: 150 Accepted data connection: Connection to the FTP server has lost

  • The following error can be found in the /var/log/plesk/PMM/backup-YYYY-DD-MM-hh-mm-ss-xxx/backup.log file:

    PLESK_INFO: INFO: Unable to resume interrupted upload[1a23b456-1a2b-1234-12a3-a1b2c456d789]: Unable to resume an interrupted upload. It seems like FTP server deleted the file, when the connection was lost. Try to repeat or perform upload manually: The connectivity problem: (55) Failed sending data to the peer: Last FTP request: STOR backup_YYMMDDhhmm.tar: Last FTP response: 150 Opening BINARY mode data connection for backup_YYMMDDhhmm.tar [:0]

  • If the option Save backups in the server storage if the upload to FTP fails is enabled at Tools & Settings > Backup Manager > Settings the locally created backup can contain the following multiple warning:

    PLESK_INFO: [WARNING]: Cannot dump domain hosting content [Curl error: Unable to resume an interrupted upload: (55) Failed sending data to the peer: Last FTP request: APPE backup_1801300838.zip: Last FTP response: 150 Opening BINARY mode SSL data connection for 'backup_1801300838.zip': Connection to the FTP server has lost]

  • The debug log  %plesk_dir%\PMM\logs\backup-YYYY-DD-MM-hh-mm-ss-xxx\backupcontains entries about several unsuccessful attempts to resume the FTP connection and upload files:

    PLESK_INFO: Debug: Curl error: (55) Failed sending data to the peer: Last FTP request: APPE backup_1801300838.zip: Last FTP response: 150 Opening BINARY mode data connection for backup_1801300838.zip
    Debug: Pause before next attempt to upload file...
    Debug: Trying to resume upload...

Cause

The FTP server or FTP user exceeded quotas or limits, e.g hard disk quota, in the middle of the backup process.

Resolution

Check and adjust the limits and quotas for the FTP server and user.

Note: if this limit is a FTP timeout, it is possible to avoid this issue by enabling multivolume backup in  Tools & Settings > Backup Manager > Schedule > Create a multivolume backup, volume size (MB).

Comments

5 comments

Sort by Date Votes
  • Avatar
    WM Dev

    Can't see "Create a multivolume backup" in Version 18.0.30 Update #3

    1
    Comment actions Permalink
  • Avatar
    Marko Puskala

    Hi,

    i tried to change volume size to 2000Mb but it wont help, even smaller size does same error. This problem was not before i installed plesk again to  new server. It would be nice to get ftp backup workin.  Seem to have something else wrong now.

    Another thing what im wondering, is that there is told to adjust limits and quotas, so are those limiting administrator / system scheduled backups too (not any sense if are).

    Thanks- 

    0
    Comment actions Permalink
  • Avatar
    George Alibegashvili

    Hello @Marko Puskala

    In this case, I can suggest submitting a request to our Technical Support: https://support.plesk.com/hc/en-us/articles/213608509-How-to-submit-a-request-to-Plesk-support-

    0
    Comment actions Permalink
  • Avatar
    SSP

    Same problem here with 4 different servers. Manual copies worked fine, so it is not a problem of size, space... I think is a plesk problem...

    0
    Comment actions Permalink
  • Avatar
    Agilehost Sales

    We have identified the same issue. What appears to be happening is that Plesk opens the SFTP connection on the target server BEFORE the backup is started. Then Plesk starts the backup process. Once the backup is completed, then Plesk tries to use that same connection to write the files to the target server. However, by this time the SFTP connection has timed out and the connection is closed. The default idle timeout for ProFTPD for example is 10 minutes. I've raised a support request with Plesk #315762 to try and get this feature changed so that the backup is created FIRST and only then is the SFTP connection opened and the backup file written.

    0
    Comment actions Permalink

Please sign in to leave a comment.

Have more questions? Submit a request

Related articles