![]() In this case, I can't see any advantage in less network traffic by using rsync+tar, which is expected when the default mtu is 1500 and while the files are 10k size. While keeping separate logs from the ssh traffic packets sent wc -l rsync.log rsync+tar.log Time (tar cf demo.tar tmp rsync demo.tar server: ssh server 'tar xf demo.tar rm demo.tar' rm demo.tar) ![]() I've created 59M demo data mkdir tmp cd tmpįor i in do dd if=/dev/urandom of=file$i count=1 bs=10k doneĪnd tested several times the file transfer to a remote server (not in the same lan), using both methods time rsync -r tmp server:tmp2 Or just scp scp -Cr srcdir rule, keep it simple. Tip2: If you use rsync over ssh, you may also use either tar+ssh tar -C /src/dir -jcf. Tip: rsync version 3 or later does incremental recursion, meaning it starts copying almost immediately before it counts all files. If you copy the files for the first time, first packeting, then sending, then unpacking (AFAIK rsync doesn't take piped input) is cumbersome and always worse than just rsyncing, because rsync won't have to do any task more than tar anyway. The tar + rsync + untar loses this advantage in this case, as well as the advantage of keeping the folders in-sync with rsync -delete. tar will always send everything and this is a waste of resources when a lot of the data are already there. I find arRsync to be an excellent program that works so well for me I have no other backup software installed.When you send the same set of files, rsync is better suited because it will only send differences. _ (as shown below) then you can rest assured that all is well with your backup. If you want to be absolutely certain your backup was successful even if you get the error message you can view the error log and if the names of all the files it had problems with start with. The screen-shot below shows the typical error you get when this happens: This results in errors being generated by rsync, but the good news is you can ignore them, your backup has still worked! This problem tends to come up most with files that you copy to your Mac from a FAT32 device like a pen-drive or a Windows machine. The second problem is not actually arRsync’s fault but rather Apple’s! There is a problem with the way the Mac version of rsync deals with resource forks on some files. I guess the developers chose to concentrate on getting the important stuff right first which is fine with me. The first is purely the fault of the tool, despite the fact that the rsync command supports synchronization across networks (via SSH), arRsync does not. I’ve been using the current release since it came out a few months back and it hasn’t crashed on me once despite the fact that I regularly backup about 300GB with it. The other nice thing about the icon in the Dock is that while you’re doing your backup it shows you a progress bar! Since large backups (few hundred GB) can take a significant amount of time, particularly if you’ve updated a lot of files or if it’s the first time you’re backing up the data, this is actually a very useful feature.Īll in all arRsync is a very good program because it does what it does very well, and despite being beta software it is still exceptionally stable. ![]() ![]() Below is a screen shot of arRsync about to start my main backup.Īs childish as it sounds, one of the things I really like about arRsync is it’s icon, it’s a skull and cross-bones with the regular circular sync icon instead of a head. Then you just have to load the profile and click a button to update the backup copy of your data. To create a backup just select what folders you want backed up to where and save it as a profile. Oh, and arRsync is both free and open-source!īackup, arRsync, Rsync, OS X The nice thing about rsync is that it only replaces files that have changed, so even if you have hundreds of GigaBytes of data, you’ll still be able to update your backup in a reasonable time. You might wonder why you would need to efficiently synchronize data between two hard-disks? The answer, backups! I use rsync (via arRsync) to backup all my important data to external hard-drives. All it does is provide a simple GUI and the ability to store profiles, but that’s all that’s needed to make rsync available to regular users. OS X only contains the command-line tool though, not a GUI to provide easy access to it. When it comes to efficiently synchronizing data between hard-drives there is a great Unix/Linux command-line tool, rsync, which is installed on OS X Tiger (and perhaps previous versions too) by default. ![]()
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