WinSCP connection to vCenter Server Virtual Appliance fails with "Received too large SFTP packet" error - VMware vCenter Server

Products

• VMware vCenter Server

Issue/Introduction

• Connecting to vCenter Server using WinSCP fails with the error:
  Received too large (1433299822 B) SFTP packet. Max supported packet size is 1024000 B
  
  
• Attempting to upload a file to the vCenter Server using the SCP protocol via WinSCP, PSCP or other SCP clients fail with the error:
  Host is not communicating for more than 15 seconds. If the problem repeats, try turning off 'Optimize connection buffer size'
  
  
• Encountering an error while attempting to SCP into vCenter via the command line.
  scp: Received message too long 1433299822
scp: ensure the remote shell produces no output for non-interactive sessions.

Environment

VMware vCenter Server

Cause

• When using WinSCP, part of the operation occurs on the target system. The default Appliance Shell cannot be the remote partner of WinSCP.

• By default, VCSA is set to Appliance Shell, but SCP requires Bash shell.

Resolution

There are 2 ways to resolve this issue.

Option 1:

Adjust the WinSCP advanced settings as follows:

1. Open Advanced settings in WinSCP.

2. Select SFTP.

3. In SFTP server, replace the default value with: shell /usr/libexec/sftp-server

Note: This method is safer than Option 2 of changing the vCenter bash shell, as it avoids risks associated with modifying Photon OS settings.

 

Option 2:

Enter the vCenter appliance in Bash shell from CLI using below command:
chsh -s  /bin/bash root

Note: If using this option, change should be reverted back with default shell updated to /bin/appliancesh after the file transfer to maintain the security posture of the vCenter appliance.

Additional Information

How to upload or download files to or from vCenter and ESXi hosts

Toggling the vCenter Server Appliance default shell