RE: [flexbackup-help] blksize parameters

[Niall B. <ni...@la...>]

CHEVALIER, Erwan wrote:
> It's ok.
> Success.
> Yes, Thanks for all Niall
> So now parameters working.
> In order to all understand, what is the difference between nst0 and st0.
> Someone had explain to me:
> St0: When you backup the device rewind then after each record.
> Not on st0.
> If it's true how it can block a test??
> This is the last question for you Master .
> Bye and thanks again.=20

Hi Erwan,
great!

The non-rewinding device (nst0) allows multiple archives on one tape.
During the test, flexbackup writes several files to tape.
Then it compares them back against where they should be on tape:
e.g. It counts 2 records forward and then compares the third file.

The difference comes when you write multiple files:

NST0 +=3D FILE 1 -=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=
=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D+
NST0 +=3D FILE 1 -=3D | =3D FILE 2 -=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D=
-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D+
NST0 +=3D FILE 1 -=3D | =3D FILE 2 -=3D | =3D FILE 3 -=3D-=3D-=3D-=3D-=3D-=
=3D-=3D-=3D-=3D-=3D-=3D+
NST0 +=3D FILE 1 -=3D | =3D FILE 2 -=3D | =3D FILE 3 -=3D | =3D FILE 4 -=3D=
-=3D-=3D-=3D+

ST0  +=3D FILE 1  =3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=
=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D+
ST0  +=3D FILE 2  =3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=
=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D+
ST0  +=3D FILE 3  =3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=
=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D+
ST0  +=3D FILE 4  =3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=
=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D+

Now when you compare FILE 1 on disk to FILE 1 on tape,
it is succesful for /dev/nst0, but fails for /dev/st0=20
as FILE 1 !=3D FILE 4

flexbackup should really trap that particular error,
and suggest that you use the non-rewinding device.
It is however, clearly marked in the config.

Good luck with your restore,
Niall

=20
> -----Message d'origine-----
> De : Niall Brosnan [mailto:ni...@la...]=20
> Envoy=E9 : mardi 7 juin 2005 19:28
> =C0 : CHEVALIER, Erwan -Syntegra FR
> Cc : fle...@li...
> Objet : RE: [flexbackup-help] blksize parameters
>=20
> Hi Erwan,
> thanks for your perseverance.
>=20
> Your config file is still set to
> $device =3D '/dev/st0'  ; though,
>=20
> It really HAS to be the non rewinding device, /dev/nst0
>=20
> On my system, this error gives the same error that you are seeing.
>=20
> Niall
>=20