I would like to understand the capabilities of GNU rsync software / utility. This is used for syncing file systems / file level data across two systems. I specifically would like to know its capabilities in syncing files ? 1) How does it replicate data changes to files ? entire file or only the incremental blocks? 2) Does it have any block level replication capabilities? 3) Can it replicate files while the file is in open state (oracle redo log file)? This is particularly a problem in windows environment, typically.
Harish <harish.naik@sanovi.com> writes:> 1) How does it replicate data changes to files ? entire file or only > the incremental blocks?It sends only the differences, using the rsync algorithm. See: http://rsync.samba.org/tech_report/node2.html -- Martin Geisler GnuPG Key: 0x7E45DD38 PHP Exif Library | PHP Weather | PHP Shell http://pel.sf.net/ | http://phpweather.net/ | http://mgeisler.net/ Read/write Exif data | Show current weather | A shell in a browser -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 188 bytes Desc: not available Url : http://lists.samba.org/archive/rsync/attachments/20051124/c6433f3f/attachment.bin
Harish wrote:>I would like to understand the capabilities of GNU rsync software / >utility. This is used for syncing file systems / file level data across >two systems. I specifically would like to know its capabilities in >syncing files ? > > >1) How does it replicate data changes to files ? entire file or only >the incremental blocks? > >As far as I know, actual changes written to file are replacing the entire file. Rsync's incremental nature only extends as far as the network usage goes.>2) Does it have any block level replication capabilities? > >Rsync is a file utility. It has no awareness of blocks. If you are using Linux (you are not, I know), check out LVM for what you want. It has generic "snapshots" support, which does what you want.>3) Can it replicate files while the file is in open state (oracle redo >log file)? This is particularly a problem in windows environment, >typically. > >Not unless the OS supports it. Rsync doesn't even have a "native" Windows version at all. It only runs on Windows through an daptive layer called "Cygwin", which brings the Unix semantics to rsync. Shachar