[olug] To RAID or not to RAID

[Christopher R. White]

very nice!

On Mon, Sep 22, 2014 at 9:09 PM, Dan Linder <dan at linder.org> wrote:

> And to follow up with my rsync backup discussion, I found the "rsnapshot"
> which appears to be a fully fleshed out implementation of the multi-state
> backups I mentioned in the previous email.
>
> Here's the URL: http://www.rsnapshot.org/
>
> It's also a pre-made package in my Linux Mint system so and it doesn't
> appear that old.
>
> Dan
>
> On Mon, Sep 22, 2014 at 8:56 PM, Dan Linder <dan at linder.org> wrote:
>
> > This reminded me of an old script I wrote up to keep a number of copies
> of
> > the data but re-using the files on-disk if the data was the same.
> >
> > Check out this URL: http://www.mikerubel.org/computers/rsync_snapshots/
> >
> > But the gist of it is this (from the page):
> >
> > rm -rf backup.3
> > mv backup.2 backup.3
> > mv backup.1 backup.2
> > cp -al backup.0 backup.1
> > rsync -a --delete source_directory/  backup.0/
> >
> > If the above commands are run once every day, then backup.0, backup.1,
> > backup.2, and backup.3 will appear to each be a full backup of
> > source_directory/ as it appeared today, yesterday, two days ago, and
> > three days ago, respectively--complete, except that permissions and
> > ownerships in old snapshots will get their most recent values (thanks to
> > J.W. Schultz for pointing this out). In reality, the extra storage will
> be
> > equal to the current size of source_directory/ plus the total size of the
> > changes over the last three days--exactly the same space that a full plus
> > daily incremental backup with dump or tar would have taken.
> >
> > BUT, BEFORE YOU IMPLEMENT THIS, PLEASE READ THE UPDATES ON THE URL LISTED
> > ABOVE.  THERE ARE SOME CLEANER METHODS TO DO THIS that will preserve the
> > ownership and permissions, and optimize disk usage after a number of
> backup
> > rotations.  (I'm sure someone has a better script that's up-to-date...)
> >
> > I did experiment with using the Win32 version of rsync many years ago,
> but
> > I don't believe it supported the
> >
> > Dan
> >
> >
> > On Mon, Sep 22, 2014 at 8:32 PM, Obi-Wan <obiwan at jedi.com> wrote:
> > >
> > > On 09/22/2014 06:19 PM, Lou Duchez wrote:
> > >>
> > >> Any chance you've got a friend out there on the Internets who would
> let
> > you keep a drive at his place?  For my remote backups, I do a two-step
> > process:
> > >>
> > >> 1)    rsync is a great way to back data up across a network (including
> > the Ethernet), especially where only a little data changes from one
> backup
> > session to the next.  So let's say I use rsync to back up my data to
> > "/backups/current" on the remote system.  Which I then follow with step 2
> > ...
> > >>
> > >> 2)    /bin/cp -al /backups/current /backups/[date]
> > >>
> > >> What that does is create a dated backup directory, but thanks to the
> > magic of the "-l" flag, hard links (not symbolic links) to the files in
> > /backups/current are created.  That means I have a logical copy of
> > /backups/current that takes up almost no additional drive space because
> > it's pointing to the same files on the file system.  Now, if any of those
> > files in /backups/current is changed the next time I run rsync, the file
> in
> > /backups/current is unlinked first and a new file is created -- but the
> > link to the original in /backups/[date] is left completely untouched.
> > >
> > >
> > > I don't see anything in the rsync man page that indicates it will break
> > that hard link when updating an existing file.  How does your setup
> ensure
> > this will happen?  If the link isn't broken, then your old hardlinks will
> > get updated along with your current file when rsync changes it.
> > >
> > > --
> > > *Ben "Obi-Wan" Hollingsworth* obiwan at jedi.com <mailto:obiwan at jedi.com>
> > www.Jedi.com <http://www.jedi.com>
> > > The stuff of earth competes for the allegiance I owe only to the
> > > Giver of all good things, so if I stand, let me stand on the
> > > promise that You will pull me through. /-- Rich Mullins/
> > >
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> >
> >
> >
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>
>
>
> --
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> "Quis custodiet ipsos custodes?"
>     (Who can watch the watchmen?)
>     -- from the Satires of Juvenal
> "I do not fear computers, I fear the lack of them."
>     -- Isaac Asimov (Author)
> ** *** ***** ******* *********** ************* *****************
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