[svlug] rsync and backup anyone?
hvrietsc at yahoo.com
Fri Jan 5 20:04:01 PST 2001
On Fri, Jan 05, 2001 at 05:37:54PM -0800, Alvin Oga wrote:
> hi ya...
> donno if rsync has a feature to turn off "deletion"...
> If rsync is used as backup of system_A.... i do not want the
> backup_system_BB to delete those same files...till some
> arbitrary time has passed...a day...a week...a month...a year...
> - some data you keep around longer than other data...
> and yes... good that rsync uses "incremental algorithms"
> i was (wishfully,stupidly) thinking... ( dreaming or not...conceptually...
> --- if the original file is 1Mb....and its changed....slightly...
> --- there is no reason to backup the entire 1Mb thing....
> - the point is like rsync and others... that the differences
> is small and no need to save the entire file... just save
> the diff patterns... ( and even if one gets hold of the backup...
> it does them no good... and its not even encrypted...
> - this is/was my silly difinition(concept) of "differential backups"
> mount backup:/Backup /mnt/Backup ( place to store backups )
> mount STABLE:/Stable /mnt/Stable ( some place to compare against )
> - Stable is considered a usable full backup as of mm-yy-dd
> # go thru a list of files.... since the last "stable full backup"
> # that will NOT change...
> cd /home/<user>
> diff src/foo.c /mnt/Stable/home/<usr>src/foo.c | tar zcvf /mnt/Backup/foo.diff.c -
> umount /mnt/Stable
> umount /mnt/Backup
> idea is there is a live full backup somewhere ( within the same building ? )....
> and only keep minimimal data on the incremental backups...
> - remember...we're trying to backup 500Gb of live data...
> - and recover within an hour or two from a disk crash.....
i you have that much data and that data is so important to you then
all you can do is buy some real commercial backup product from a company
that will garantee it.
> have fun
> > Jeremy D. Zawodny wrote:
> > On Fri, Jan 05, 2001 at 11:17:43AM -0800, hvrietsc at yahoo.com wrote:
> > > I must admit i have not read all the many backup emails flying
> > > around but did anyone mention the use of rsync for backups yet?
> > >
> > > (if yes then delete this message, if no keep reading if you want)
> > >
> > > rsync will keep two (or more computers) in sync and will only ship
> > > differences across the wire so its real quick.
> > >
> > > I know this is not _real_ backup, but having the same data on two or
> > > more machines does give some safety. I regularly run rsync between
> > > my desktop and laptop so that i have a full copy of my laptop (/etc
> > > /root /home /etc) just in case. after the initial rsync all
> > > incrementals are quick (due to rsyncs incremental algorithms).
> > Yep. I do something very similar at home. I have a couple of spare
> > filesystems on large hard disks. One is mounted as /backup/home and
> > another as /backup/root. I have a cron job in place to periodically
> > rsync so that if the real thing dies, I don't lose much data.
> > Hey hard drives are cheap... why not? :-)
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