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Re: Sugesstions building a rather big mail system.

On 09 Oct 2003 10:31:25 +0200, you wrote:

>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 agree with that comment. Also somebody asked how to get it with
Linux. Tip: use LVM + dump.
- LVM will provide snapshot capability -> avoids files changing when
backing up (as told by Donovan)
- Dump is the tool used for taking backups (complete or incremental)

>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 5AM you should:
- create a LVM snapshot (this is very fast, since LVM doesn't really
need to copy data from the real fs to the "snapshot fs").
- dump fs completely
- destroy LVM snapshot

At 6AM you should:
- create a new LVM snapshot
- dump fs partially (incremental mode)
- destroy LVM snapshot

>Is anyone on
>the list you uses this features and can tell what they really do or how
>good they work?

Well, I haven't tested enough and I really don't have big and loaded
systems as the one you want to use, but all my tests have been very

Read the following thread that I started a few weeks ago:


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