On Sun, 17 Mar 2019 at 16:11, Andrew Greig via luv-main <luv-main@luv.asn.au> wrote:

I have just used grsync to ensure that my RAW datafiles on my RAID 1 drive and a copy of the RAW datafiles on my External hard drive are consistent by effecting necessary changes on the external drive as necessary. But what I now have (5 hours later) is a whole new copy of the RAW datafiles inside the existing directory on the drive, this has doubled my storage (200Gb to now 400GB),

Hi Andrew I have never used grsync but if it is anything like rsync then what you describe sounds very much like what might occur if someone was unaware that the commands rsync source_directory destination_directory and rsync source_directory/ destination_directory have different behaviour. (note the second command has a / in it, and the first does not). I suggest you read a few paragraphs in the rsync manual here: https://manpages.debian.org/stretch/rsync/rsync.1.en.html#USAGE and compare the examples given rsync -avz foo:src/bar /data/tmp and rsync -avz foo:src/bar/ /data/tmp and note the sentence following that one: "A trailing slash on the source changes this behavior to avoid creating an additional directory level at the destination" and the following paragraphs. I have a hunch this is likely to solve your puzzle. It might also be a good approach to do some commandline experiments using a small test directory so that you don't have to wait 5 hours each time, until you understand how the command works. Regards David