LVM snapshots vs. --link-dest

[Andrew Gideon]

On Sun, 27 Sep 2009 17:14:42 +0000, Andrew Gideon wrote:


> Where this "fails" is for large files that have received small changes.
> The directory containing my main IMAP account, for example, typically
> generates between 1 and 2 G of daily backup data as I file messages in
> my inbox.  Yesterday, though, I filed some old messages in my inbox. 
> This touched files I don't typically touch.  They were minor changes in
> the scheme of things, but the result was an 11G backup of that volume
> last night.

Several people have emailed me suggesting that I change mailbox formats.  
Rather than replying to each of them individually...

You're all quite right.  I should (and eventually will) make that 
change.  I do appreciate the suggestion.

But my mailbox case was just one example of a general issue: --link-dest 
doing nothing to save backup space in the case where a large file is 
subjected to a small change.  LVM snapshots may offer a solution to this 
general problem, and it is that idea that I'm hoping to explore here.

Thanks again...

	Andrew