The "Could not lchown() symlink" error message in Rsnapshot is usually seen when the Rsnapshot process is unable to change the ownership of a symbolic link (symlink) on the filesystem.
This error can be caused by a number of factors, such as insufficient permissions, or a problem with the filesystem.
To fix this error, you need to first determine the cause of the problem. One way to do this is to check the permissions on the symlink and ensure that Rsnapshot has the necessary permissions to modify it.
You can use the ls -l command to view the permissions on the symlink, like this:
ls -l /path/to/file
This will display the permissions on the symlink, along with the owner and group.
If the Rsnapshot process is running as a different user or group than the owner of the symlink, you may need to change the ownership of the symlink using the chown command.
For example, to change the ownership of the symlink to the rsnapshot user and group, you can use the following command:
chown rsnapshot:rsnapshot /path/to/file
Alternatively, you can also add the rsnapshot user or group to the owner or group of the symlink, like this:
chown root:rsnapshot /path/to/file
This will add the rsnapshot group to the group ownership of the symlink, but leave the owner unchanged.
If the problem is not caused by permissions, it could be due to a problem with the filesystem. In this case, you may need to run a filesystem check utility, such as fsck, to repair any errors on the filesystem.