Re: Sugesstions building a rather big mail system.

[Markus Oswald <moswald@iirc.at>]

Am Don, 2003-10-09 um 02.50 schrieb Donovan Baarda:

> Using snapshots to do an incremental backup would be no different to
> doing any other type of backup using snapshots. It's the same as a
> normal incremental backup, just with the added guarantee that the
> filesystem is not changing underneath you as you do it.

I guess I haven't described clearly enough what I mean - maybe I have
misunderstood the concept (I first heard about this in a speech of a
sales rep. from NetApp)

I was told that some storage appliances - for example some bigger NetApp
- can do Backups using "incremental" snapshots. This doesn't mean they
make a snapshot and than create a backup from it to get consistent data,
but use a bunch of snapshots itself.
Say the first snapshot is created at 05:00 AM with 10TB data on the
filer and the second one one hour later at 06:00 AM the "incremental
snapshot" would backup only those blocks/files/whatever that have
changed since then (maybe just a few GB). This allows much faster
backups/restores with guaranteed consistency.

At least thats how I understood it about a year ago - the concept sounds
really nice to me, but neither the filers nor the software wich allows
this procedures are cheap so I couldn't play with it yet. Is anyone on
the list you uses this features and can tell what they really do or how
good they work?

>From a quick glance at their website I think it's called "SnapRestore"
http://www.netapp.com/products/filer/snaprestore.html

Disclaimer: I don't work for NetApp or any of their associates nor did I
in the past. I don't even sell their products ;-)

best regards,
 Markus
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