Re: [Dump-users] Definition of dump levels?

[Scott E. <sc...@MI...>]

On Sat, 5 Jan 2008, Stelian Pop wrote:

>
> Le samedi 05 janvier 2008 =E0 08:23 -0500, Scott Ehrlich a =E9crit :
>> I've seen so many references to dump levels, but none of them, including
>> the man page, actually says what, specifically, each level covers.
>
> Well, the man page says what each level covers pretty clearly:
>
>   A level 0, full backup,  specified
>   by  -0 guarantees the entire file system is copied
>   ...
>   A  level  number  above  0,  incremental
>   backup,  tells  dump to copy all files new or modified since the
>   last dump of a lower level.
>
>> For example, a level 0 would presumably back up everything.
>
> Yes.
>
>>  But will it
>> still do so if I perform a level 0 today, update /etc/dumpdates, then
>> perform another level 0 just after, and no files have changed?
>
> Yes.
>
>>
>> What about the other levels?  What do they do?
>
> level 0 =3D always full dump
> level 1 =3D changed files since the last level 0
> level 2 =3D changed files since the last level 0 _or_ 1
> etc...
>
> /etc/dumpdates is here just to record when the last level 0, last level
> 1 etc were performed. If this file is missing (or not updated), dump
> acts as if the lowel-level dump was never performed. This means that a
> 'dump -5' for example will do a full dump is you haven't done a level 0,
> 1, 2, 3 or 4 at some time before.

I guess what is/was confusing me was the tower example in the man page.=20
It made me think there was something special to the levels beyond just=20
making differentials.  From another email I received, I learned that a=20
level 3 cannot occur until a level 2 exists, and a level 2 cannot occur=20
until a level 1 exists, etc.  The tower example in the man page, at least=
=20
to me, made me think a level 3 could occur now, just after a level 0, then=
=20
a level 2, then...

Scott

>
> Stelian.
> --=20
> Stelian Pop <st...@po...>
>
>