Re: [SLE] backing up a partition
tabanna
Indeed. `rsync' is a wonderful tool, which should be known.
~ do please expand :)
`rsync' is especially useful when synchronising big hierarchies over a slow communication link, as it only transmit _differences_ between files. For me, this greatly speeds things up, often by a factor of thousands. Let me add one more little mind teaser. I leave you to guess how `rsync' succeeds in computing differences, without transferring the files :-). I often synchronise many hierarchies at once, and use `make' to do so with its parallelising feature (like `-j4'). This makes very good use of computer and communication resources. I'm surprised to see how well `rsync' keeps the communication busy in both directions (receiving and sending), and balanced with disk accesses and moderate CPU usage. You can trigger `rsync' remotely using `rsh' or `ssh', yet I usually install an `rsync' server only on the machine where I keep originals, and synchronise from everywhere by connecting to that server. P.S. - Long ago, I once wrote something to do remote synchronisation of remote directories, using email as a vehicle. It is called `remsync' and is available within GNU `shar' utilities. I used `remsync' a great deal, and invested a lot of work in it. Yet, when Jim Meyering discovered `rsync', he told me, I tried it, and was astonished. After a few weeks of experimentation, I completely lost interest in `remsync', and do not think I'll ever use it again. I'll rather find ways to retrofit `remsync' into `rsync', if I had no choice than using fully off-line, non-IP connections. -- François Pinard http://www.iro.umontreal.ca/~pinard -- To unsubscribe send e-mail to suse-linux-e-unsubscribe@suse.com For additional commands send e-mail to suse-linux-e-help@suse.com Also check the FAQ at http://www.suse.com/Support/Doku/FAQ/
François Pinard wrote:
tabanna
écrit: Indeed. `rsync' is a wonderful tool, which should be known.
~ do please expand :)
`rsync' is especially useful when synchronising big hierarchies over a slow communication link, as it only transmit _differences_ between files. For me, this greatly speeds things up, often by a factor of thousands. Let me add one more little mind teaser. I leave you to guess how `rsync' succeeds in computing differences, without transferring the files :-).
There is a papper on the web server but basically it sends checksums of blocks of the files and compare them, it can update parts of a file as well so that if you change just 1 letter in a file you only have to transfer a part of the file. /Michael -- This space intentionally left non-blank. -- To unsubscribe send e-mail to suse-linux-e-unsubscribe@suse.com For additional commands send e-mail to suse-linux-e-help@suse.com Also check the FAQ at http://www.suse.com/Support/Doku/FAQ/
participants (2)
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Michael.Salmon@uab.ericsson.se
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pinard@iro.umontreal.ca