DR backup or copycluster script fails

Products

• CA Infrastructure Management
• CA Performance Management - Usage and Administration
• DX NetOps

Issue/Introduction

Errors are seen trying to run the Vertica backup.

Unable to run local backup for Vertica using vbr.py script.

Unable to run remote backup for Vertica using vbr.py script.

We are trying to set up a Vertica backup using vbr.py.

We are trying to set up a Vertica copycluster using vbr.py.

We have validated that the dradmin user has passwordless ssh enabled and working.

The backups fail with this message:

[dradmin@hostname backup]$ /opt/vertica/bin/vbr.py --task backup --config-file /home/dradmin/backup/backup_snapshot.ini
Error: Errors connecting to remote hosts: <IP>.  Check SSH settings, and that the same Vertica version is installed on all nodes.
Backup FAILED.

Environment

All supported DX NetOps Performance Management releases

Cause

The ssh configuration in the sshd_config file is set with No for AllowTcpForwarding.

Resolution

Vertica requires AllowTcpForwarding set to Yes in the /etc/ssh/sshd_config on both source and destination systems.

To resolve the error take the following steps on all systems involved, both source and destination.

1. Edit the /etc/ssh/sshd_config file settings.
   1. Ensure the AllowTcpForwarding option is uncommented.
   2. Set the AllowTcpForwarding option to Yes.
   3. Save the file changes
2. Restart the ssh service for it to read in the new configuration. To restart it for RH 7.x releases run
   • systemctl restart ssh

The backup command using vbr.py should succeed.

Additional Information

Vertica Configuring Backup Hosts documentation

Notes/Tips for SSH configuration:

• AllowTcpForwarding is commonly commented out in the sshd_config file by default. If that is seen ensure the comment (# symbol) is removed from the start of the line.
• AllowTcpForwarding must be set to Yes on both source and destination systems.
• To further restrict to tcp forwarding to just one user you can add the following line to the sshd_config file.
  • Match User dradmin
• The ssh service MUST be restarted before it will recognize changes to the sshd_config file settings.
• RH 6.x releases would restart the service with "service ssh restart".