Merge directories with rsync

xeon123 · 05-06-2015, 11:38 AM

I have 2 directories that I want to merge with rsync so that in the end both have the same and most recent files. How can I do this with rsync?

maples · 05-06-2015, 12:09 PM

What do you have so far?

I think this should take care of it:

Code:

cp -r /path/to/first/source/ /path/to/destination/
rsync -av --update /path/to/second/source/ /path/to/destination/ --dry-run

The first command copies the first source to the destination.
The second command copies the contents of the second source to the destination ONLY if the file in the second source is NEWER than the file in the destination. The "--dry-run" flag will make rsync print what it's going to do, but not actually do it. If the output looks like it will accomplish what you want, then remove that flag and it will copy it for real.

Hope this helps!

suicidaleggroll · 05-06-2015, 12:57 PM

A simple "rsync -ut" in both directions should do it. Note, however, that if the same file has been modified on BOTH sides, ONLY the newer one will be retained. Also note that deleting files can be a pain, since you need to delete it on both sides before the next time the script runs or it'll be copied back over.

Code:

rsync -ut /path/to/source/ /path/to/destination/
rsync -ut /path/to/destination/ /path/to/source/

I use this all the time to keep various config files synchronized between multiple systems. I just need to make the change on one of them, and the next time the script runs all of them are updated.

Mr. Alex · 05-06-2015, 01:50 PM

Code:

rsync -av --delete /dir/what /where

is my way to use it most of the times.

Note that

Code:

rsync -av --delete /dir/what /where

differs from

Code:

rsync -av --delete /dir/what/ /where

First one will copy (sync) the whole "/dir/what" whereas the second one copies the contents of "/dir/what". Rsync's approach differs from bash here.

suicidaleggroll · 05-06-2015, 02:20 PM

I don't want to speak for the OP here, but he did say merge, not back up. Merge implies that there are changes on BOTH sides that need to be synced to the other. A simple rsync run in one direction will only update the destination, not the source, and you definitely do not want to use --delete or any files created on the destination that aren't on the source yet will be removed.

It could be that the OP simply didn't use the right word to describe what he wanted to do, but he should be well aware of what these flags are doing lest he accidentally run a command that removes or overwrites important files.

xeon123 · 05-07-2015, 03:56 AM

@suicidaleggroll, In this case I mean to update/"make a backup" of 2 dirs with the most recent files. So, I have a dir called "mydir" in disk1 and disk2, and I want that "mydir" will have the same and most recent content in disk1 and disk2.

Since I have updated this dir in both disks at different times, they are different. Now I want to merge both dirs with the most recent files, and if there is a conflict in the same file, the most recent updated file will prevail. So, all the solutions that the rest of users gave me are ok.

maples · 05-07-2015, 08:38 AM

Quote:

Originally Posted by xeon123

@suicidaleggroll, In this case I mean to update/"make a backup" of 2 dirs with the most recent files. So, I have a dir called "mydir" in disk1 and disk2, and I want that "mydir" will have the same and most recent content in disk1 and disk2.

Since I have updated this dir in both disks at different times, they are different. Now I want to merge both dirs with the most recent files, and if there is a conflict in the same file, the most recent updated file will prevail. So, all the solutions that the rest of users gave me are ok.

In that case, post #3 looks like the one you want.