Hi, I have few questions that could not find answers to in documentation. Different filesystems: Lets say I want to keep all extended attributes and everything else, so I use -A, -X, --perms etc., together with --fake-super. Now, lets say source FS supports some attributes not supported on target FS (for example, XFS extended attributes). Would this work as expected (ie. extended attributes are kept on target somehow)? Reversing --backup logic: Currently, if --backup is used (and --backup-dir), a copy of existing file that is replaced on rsync will be placed there. Is there a way to keep original copy (ie. base) the same, but just place whatever has changed to a different location? Taking "backup to a central backup server with 7 day incremental" example on rsync page, but reverse the logic. Instead of current, you have 'initial' and then each incremental only contains changed files from 'initial' (basically, each incremental would then be differential, but thats besides the point). delta-xfer algorithm: Does delta-xfer detect change in following case: lets say file contains data like "<data>", and is rsynced. Before next rsync, file data changes to "<prefix><data>", where <prefix> is some stream of bytes. Will rsync trasfer only <prefix> data (and detect content has just moved in a file) or will whole file be transfered? Saving delta-transmition stream: Is it possible to save delta-transmition stream (or whatever rsync is sending) as intermediate result? For example, save this stream, and feed it later to another rsync that then applies it to base? Basically, I'm interested if rsync stream can be somehow stored for later use, to minimize number of files on disk (stream changes into single file for example, put it to tape etc.). For example, tar could be used to achieve this after rsync does its job, but I'm interested in other possibilities. Thank you for your answers, Igor
> Reversing --backup logic: > Currently, if --backup is used (and --backup-dir), a copy of existing > file that is replaced on rsync will be placed there. Is there a way to > keep original copy (ie. base) the same, but just place whatever has > changed to a different location? Taking "backup to a central backup > server with 7 day incremental" example on rsync page, but reverse the > logic. Instead of current, you have 'initial' and then each > incremental only contains changed files from 'initial' (basically, > each incremental would then be differential, but thats besides the > point).One thing to keep in mind is that when performing a restore, you may want to recreate a directory structure from the backup rather than just restore a single file. As such, LBackup <http://www.lbackup.org> may be worth considering. However, you may not need the ability to recreated the directory structure from your backup and as such it may not be the right tool for you. LBackup uses hard links to store each backup snapshot as a complete backup tree. This snap shot approach allows you to browse your backup tree. When you perform a restore from the backup tree you are able to restore individual files. However, you are also able to recursively restore a directory structure. In addition, you are able to utilize additional utilities (eg. find, grep, etc...) to assist with the restore of specific files or entire directory structures generated on the fly with scripts. In addition, LBackup includes the lcd command <http://www.lbackup.org/command_line_tools> which allows you to change your current working directory forwards and backwards though time. This assists with locating the files and directories which you wish to restore. The lcd command bundled with LBackup is scriptable and that means that you have the ability to have create scripted backup tree searches. To see lcd in action visit the URL below and click on the link to the lcd screen cast : <http://www.lbackup.org/screencasts>> (stream changes into single file for example, put it to tape etc.)LBackup may not be an option for you as it has no support for backup directly to tape. LBackup used rsync extensively for the coping of files. As I understand the way which rsync (currently) works there is no support for rsync to sync directly to tape. You should be able to use tar after running rsync to disk, in order to transfer your files to tape. Perhaps LBackup will assist you with your D2D backups? More backups the better! ---------------------------------- This email is protected by LBackup http://www.lbackup.org
On Tue, 2010-06-22 at 13:59 +0200, Igor Lautar wrote:> Different filesystems: > Lets say I want to keep all extended attributes and everything else, > so I use -A, -X, --perms etc., together with --fake-super. > Now, lets say source FS supports some attributes not supported on > target FS (for example, XFS extended attributes). Would this work as > expected (ie. extended attributes are kept on target somehow)?The target filesystem must support extended attributes using one of the APIs that rsync understands, because that's where --fake-super stores its data.> Reversing --backup logic: > Currently, if --backup is used (and --backup-dir), a copy of existing > file that is replaced on rsync will be placed there. Is there a way to > keep original copy (ie. base) the same, but just place whatever has > changed to a different location? Taking "backup to a central backup > server with 7 day incremental" example on rsync page, but reverse the > logic. Instead of current, you have 'initial' and then each > incremental only contains changed files from 'initial' (basically, > each incremental would then be differential, but thats besides the > point).You can do that with --compare-dest, but you might prefer a hard-linked backup series with --link-dest.> delta-xfer algorithm: > Does delta-xfer detect change in following case: > lets say file contains data like "<data>", and is rsynced. Before next > rsync, file data changes to "<prefix><data>", where <prefix> is some > stream of bytes. Will rsync trasfer only <prefix> data (and detect > content has just moved in a file) or will whole file be transfered?The delta-transfer algorithm will handle that properly.> Saving delta-transmition stream: > Is it possible to save delta-transmition stream (or whatever rsync is > sending) as intermediate result? For example, save this stream, and > feed it later to another rsync that then applies it to base?See --{write,read}-batch . -- Matt