These are usually periodic e. The ability to resume interrupted transfers also makes it suitable for exchanging very large files between two different computers.
Of course, it's not limited to these use cases; the large amount of command line options make it easily adaptable to other scenarios administrators may encounter. This means that if you have a large database on server1 and you copy it to server2, the first transfer will be normal but subsequent transfers will be much faster.
For example, you may have a GB database, but since the last synchronization, only a few megabytes have changed. Data can also be compressed before it is sent to the remote location, shortening the time it takes to complete transfers even more, especially in the case of highly compressible content e. In this article, we will be using rsync on our Elastic Compute Service ECS instance to synchronize files and directories between two locations.
Check your distribution's manuals to see the command you should use. If you've just launched a fresh instance, you might have to update package information before running those commands e. To copy a file from one location to another, on the same machine, the general syntax of the command is:. For large files, it may be useful to add -P as a command line parameter to track progress expressed in percent of file copied , e.
For directories containing numerous files, it may be useful to add the -v verbose parameter to display the file currently being synchronized, which can give you an idea on how the job is progressing:. For example, if you would use this command:. So a command like:. It is important to remember this subtle difference, especially if you use the TAB key to autocomplete paths you type in the command line.
Normally, the Bash shell automatically adds a trailing slash when autocompleting directory names. Solution 2: Old-school rsh-server However, the configuration was way too complicated for me.
We use rsync extensively here and usually get full interface speed unless traversing millions of 4K files. I don't think the crypto is the problem unless you're using some seriously decrepit hardware.
If not, why is rsync over ssh slower than rsync over rsh then? Encryption is often a limiting factor in rsync speeds, along with the number of files.
See hpn-ssh : psc. Law29 Law29 3, 1 1 gold badge 15 15 silver badges 28 28 bronze badges. It's also worth mentioning that OpenSSH 6. That's kind of a pity bparker! Do we know which of the remaining available ciphers is lightest on the CPU? I am just copying hundreds of gigabytes of video files. The Overflow Blog. Does ES6 make JavaScript frameworks obsolete? Podcast Do polyglots have an edge when it comes to mastering programming Featured on Meta.
Now live: A fully responsive profile. Linked 5. Related Hot Network Questions. Question feed. Server Fault works best with JavaScript enabled. Accept all cookies Customize settings. Rsync will obviously be faster than scp if the target already contains some of the source files, since rsync only copies the differences. But I suspect your question was about doing a straightforward copy to an empty target. You've passed the -z option to rsync ; this turns on compression. If the network bandwidth is the limiting factor it often is , compression can improve the transfer speed by a noticeable amount.
You can also enable compression with scp by passing the -C option. This should about even things out with rsync. Compression is not enabled by default in ssh because it saves bandwidth but adds latency and CPU overhead; latency is bad for interactive sessions this doesn't apply to scp , and the CPU overhead is useless if the files you're copying are already compressed. Older versions of rsync used rsh rather than ssh as the default transport layer, so a fair comparison would be between rsync and rcp.
But ssh has been the default since 2. With identical compression settings, I'd expect rsync and scp to have essentially the same speed. Please share benchmarks if you find otherwise. It used to be the other way around, but I believe rsync's speed has improved greatly the past few revisions.
It also depends on how many files you're copying. If it's a lot, rsync will usually be faster because scp spawns a new process for each file you're copying. You can try weakening the cipher scp uses to see if it speeds up. Last I recall, the arcfour cipher was the fastest. For my testing, rsync is faster than scp , you can use iotop to test them on transfering the same file:.
Maybe you'll get different result, but you can test them youself. BTW, while using scp , do not foget to choose its cipher by:. Alex Chamberlain Alex Chamberlain 1, 3 3 gold badges 16 16 silver badges 26 26 bronze badges. Also, pretty sure rsync has to be installed on the other end. I like scp's simplicity. Is it a new feature? Just tried this using version 3. This is why most large sites don't support it, and why zsync was created as an alternative.
Show 3 more comments. Might be worth adding that the --partial flag is useful when transferring large files. As Flup mentioned rsync won't leave anyt file-in-transit around for you to resume unless you use the --partial option. These files are by default hidden in the target directory. You can use --partial-dir to put all of these files in a single directory.
See this answer on Stackoverflow — Devesh Saini. Add a comment. Devesh Saini Devesh Saini 2 2 silver badges 4 4 bronze badges. In fact, rsync a host:b is equivalent to scp a host:b. That's what I wrote, rsync can transfer deltas between local and remote hosts but scp is not limited to just that, it can transfer deltas between two remote hosts.
User Chris at Webhosting Talk writes: rsync compares the files at each end and transfers only the changed parts of changed files. Toby Speight 7, 1 1 gold badge 18 18 silver badges 44 44 bronze badges.
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