[K12OSN] backup question

[Robert Arkiletian]

On 6/20/05, Rob Owens <hick518 at yahoo.com> wrote:

> rsync works differently than cp.  rsync is supposed to
> take a "snapshot" of the files, and then copy them all
> as they were at that instant in time.  (I'm sure it's
> not an "instant", but it's apparently a very short
> period of time).  cp on the other hand copies files
> one by one, so if the files are changing while the
> copying is being done, you may not end up with a
> usable backup.  For instance, supppose some process
> modifies files A and Z while you are doing cp.  When
> cp started, you copied the old "A", but by the time cp
> gets to copying "Z", you're copying the new "Z".

Okay this is the explanation I was looking for.  Thank you.

> 
> Everybody who is interested in backups should take a
> look at this link:
> http://www.mikerubel.org/computers/rsync_snapshots/
> 

It's bookmarked. I'll definetely read it. Excellent link.

> It gives an excellent explanation of how a good backup
> system works.  After reading it, I chose to run a
> program called rsnapshot, which is linked off of this
> page.  It works very well for me for home use.  I
> think backuppc would probably be better for a network
> evironment, because it can pool files from multiple
> machines (according to Les' recent post).  But no
> matter what, read that link.  It is great information.

-- 
Robert Arkiletian
C++ GUI tutorial http://fltk.org/links.php?V19