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Nice Rsync

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I honestly would be interested in learning why tar is better in that case. Greg +1 Informative Posted Aug 25, 2010 13:25 UTC (Wed) by dmarti (subscriber, #11625) [Link] Just ssh-ed in to a FreeBSD 7.2 system -- `cp -a` works, and `-a` is in As far as I understand, when rsync acts on local files, in addition to a "normal" cp, rsync is only computing the whole file checksum. I'm always looking for new clients so I'd love to hear from you.

This seems like what you want anyway since things other than tar are capable of performing computationally expensive tasks, its just that youre seeing tar do it the most. A look at rsync performance Posted Aug 19, 2010 15:19 UTC (Thu) by jcvw (subscriber, #50475) [Link] The same performance problems occur when retrieving data from an rsync package like so: If Dropbox can do it so can we! =) I didn't say, but i also tried without -c, still slow. –Johan Allgoth Jun 16 '10 at 12:14 1 also --inplace Why would you do something like that over a simple "cp"?

Nice Rsync

For example, limit I/O banwidth to 10000KB/s (9.7MB/s), enter: # rsync --delete --numeric-ids --relative --delete-excluded --bwlimit=10000 /path/to/source /path/to/dest/Method # 2: Take control of I/O bandwidth using ionice How are water vapors not visible? The file changes often. I've not looked recently to see if that's still the case, and given the performance numbers in the article it may not be the case (eg, the kernel's readahead may do

  • To also force dirty pages to be flushed, we first use the sync command.
  • Once I found out that it was in fact possible to game on Linux via.
  • A look at rsync performance Posted Sep 8, 2010 15:52 UTC (Wed) by daenzer (✭ supporter ✭, #7050) [Link] Indeed, this seems like an rsync performance bug that should get fixed.
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  • My experiences is that tar+ssh beats scp significantly.

Why would two species of predator with the same prey cooperate? Measuring Wanting to know what happened, I created a small test to see what was going on: copying a 10GiB file from one disk to the other. That's why I use tar. Rsync Bwlimit up vote 8 down vote favorite 7 I need to move a large file (corrupt MySQL table ~40GB) onto a seperate server in order to repair it. (When trying to repair

I am quickly running out of disk space so need to get this table repaired and archived ASAP. I use -avP --delete to sync a multi-terabyte tree and it performs admirably. I would like to reduce both disk and network I/O. It is clear that the default setting are not the worst settings, but close to it.

For comparison, I also ran the tests with a more recent kernel that does not incorporate Arjan's patches: 2.6.34 I could immediately see (in atop) that the three rsync processes were Rsync Whole File You must separately specify -H. FWIW, I initially learned about this here: http://www.screenage.de/blog/2007/12/30/using-netcat-and-tar-for-network-file-transfer/ share|improve this answer answered Jan 2 '16 at 5:52 SteveLambert 1936 1 tar is better than rsync when you have a lot I guess it is similar to the cpulimit tool Huygens suggests. –Nicolas Raoul Jun 1 '12 at 5:57 Except Huuygens' tool is much better and more practical, which is

Rsync Cpu Usage

I am using this command: tar cf /media/MYDISK/backup.tar mydata PROBLEM: My poor laptop freezes and crashes whenever I use 100% CPU or 100% disk (if you want to react about this http://superuser.com/questions/153176/how-to-rsync-a-large-file-with-as-little-cpu-and-bandwidth-expense-as-possible At the highest frequency, cp only needed 0.34+20.95 seconds CPU time, compared with rsync's 70+55 seconds. Nice Rsync Why do CDs and DVDs fill up from the centre outwards? Ionice Examples Explaining both in part what goes wrong, where it goes wrong, and something about how to fix parts of it.

thanks dave dtra View Public Profile View LQ Blog View Review Entries View HCL Entries Find More Posts by dtra Thread Tools Show Printable Version Email this Page Search After some reading around and checking out benchmarks I decided to go with 'arcfour' rsync -av --whole-file -e ssh -c arcfour {source} {destination} Lower execution priority FInally, I change the execution asked 6 years ago viewed 14603 times active 1 year ago Linked 3 Rsync very slow Related 4How can I get rsync to ignore missing files?1How do I specify a large What is the difficulty of an encounter when a monster can transform? Rsync Ssh Arcfour

Using strace, it can be shown that cp only uses read() and write() system calls in a tight loop, while rsync uses two processes that talk to each other using reads tar limit share|improve this question edited Jun 1 '12 at 6:02 asked May 31 '12 at 7:52 Nicolas Raoul 1,94972639 1 What a clever idea to make such huge tarball Was bitten by this once... I would suggest that kernel offers a way for applications to signal that they are behaving poorly because they do not have enough CPU power available, or some way to request

It's always a problem if you launch a 'cp -au' because the mtime of the file is only set once the copy is finished (for obvious reasons), so interrupting the copy Rsync Performance Just add nice in front of your backup command. Unix & Linux Stack Exchange works best with JavaScript enabled LWN.net News from the source ContentWeekly EditionArchivesSearchKernelSecurityDistributionsEvents calendarUnread commentsLWN FAQWrite for us EditionReturn to the Development page User: Password: | |

A look at rsync performance Posted Aug 19, 2010 10:56 UTC (Thu) by dafid_b (guest, #67424) [Link] ok - i read the fine cp manual page and now think that preserving

It was insane. You are currently viewing LQ as a guest. The future An LWN article described problems that the ondemand scheduler has in choosing the right CPU frequency for processes that do a lot of I/O and need a lot of Rsync Man I am transfering from one part of my production server to the other, i.e.

Not sure. Just curious in any case. As it stands now, it's got a 50% duty cycle. In order to do this, I want to rsync the .frm, .MYI and .MYD files from my production server to a cloud server. In the time the processor is waiting for the I/O to finish, the clock frequency is scaled down almost immediately.

share|improve this answer answered Jun 1 '12 at 12:19 Patrick 36k885133 Thanks, but I am already at the lowest possible frequency. Is it correct otherwise? The second backup, the backup of the backup to another computer via. Pick a frequency (lets say 1234567) and do echo 1234567 > scaling_max_freq This will prevent the CPU from ever going above the specified frequency.

The kernel plays a role too On my 4-core AMD Athlon II X4 620 system, all three processes seem to run on the same CPU most of the time. At the very least it doesn't seem to be CPU-bound, but disk I/O bound or, in case of the network copy, network-bound. Introduction to Linux - A Hands on Guide This guide was created as an overview of the Linux Operating System, geared toward new users as an exploration tour and getting started