Most effective way to incrementally backup vmware player images with rsync

Are you using the -T flag on vmrun to indicate that the target is a vmware player?:

-T <hostType> (ws|server|server1|fusion|esx|vc|player)

I was able to run suspend with:

$ vmrun -T player suspend /export/vmware/cmp/cmp.vmx

That's with the player version (3.0.0 build-203739) included in VMWare Workstation 7 (on Ubuntu 9.10).

I think you are misunderstanding both the checksum and hard link options.

The --checksum option is described in the man page as "skip based on checksum, not mod-time & size". It means that mod time and size are basically ignored, but it does mean that all files are read on both sides (because it has to read the file to compute the checksums.

It's important to realize that rsync does this anyway if the time and size are different. So --checksum causes much more work (reading every file), than without it. Without it, the checksums are done only if the mod time or size are different. As said above, this only influences what files to skip.

--checksum is typically used in backup scripts for the equivalent of a "full backup", say once a month. This ensures that any file which may have changed, but in such a way that the mod time and size remain the same, get correctly backed up.

The --hard-links option (from the man page): "This tells rsync to look for hard-linked files in the transfer". Note that it is only in the transfer, so it won't detect that you have an existing copy of the data on the rsync server, in another location, and hard link it. It only links files that are being transferred with other files that have previously been transferred.

So, if you want the new laptop's backup directory to be hard-linked to the old laptop's backup directory, you will need to remove the new laptop's backup directory, and re-create it using hard links (say, via cp -al). However, if all of your file dates have changed, you're likely going to run into issues with rsync re-transferring these files and breaking those hard links. You'd first probably need to rsync the one laptop to the other, being careful not to rsync over data that truly needs to be different between them. That way the files should have the same dates, and that will make your rsync backups happier.

I know you've said you read the man page, but I'd encourage you to look at it again, specifically the detailed descriptions of the --checksum and --hard-links options. You probably should also read about the --in-place option as well, as it may interact badly if you are trying to preserve hard links.