[ILUG] Does afio work with cdrecord?

[Patrick Stack]

On Fri, 2005-08-26 at 19:08 +0200, Brian Foster wrote:
>   | Date: Fri, 26 Aug 2005 11:50:03 +0100
>   | From: P at draigBrady.com
>   | 
>   | Patrick Stack wrote:
>   | > I'm trying to backup my /home directory prior to upgrading FC4 using
>   | > afio with cdrecord with no success.
>   | > I'm using the following command which I've adapted from the example
>   | > given in [ afio(1) ].
>   | > find /home/patrick/* | afio -o -b -K -b 2048 -s 614400x '!cdrecord dev=0,0,0 -'
>   | > 
>   | > This seems to work and checks the data (-K) [ ... ]
> 
>  why do you think it “works“?
>  why do you think it really is checking the data?
>  what, in fact, do you think it is doing when
>  checking the data?

I must admit I have little idea what it is doing and haven't thought
about it either. I'm a relative beginner having worked with Linux for
only 11 months and that mainly on php and mysql.
I'm picking things up on a need-to-know basis as time is pressing. So
all I'm interested in is getting things to work as quickly as possible.

>  like Pádraig, I've never used afio(1) either,
>  but I suspect at least part of the problem is
>  the `-K'.  it is very likely — and the manual
>  page (for v2.5) implies this — that `-K' does
>  read-after-write verification.  it is unclear
>  if it verifies on a sector-by-sector or image-
>  by-image basis, but in either case, it cannot
>  possibly work.
Yes, you're probably right. I stuck in the -K switch because I wanted
some way to verify the backup on the fly, which was probably a bad idea.
> 
>  to start with the obvious, `afio' has _no_idea_
>  what device to read back!   and then, _if_ it is
>  sector-by-sector, it clearly cannot work:  you
>  cannot read a CD that is still in the process
>  of being recorded.
> 
>  the example of using cdrecord(1) in afio(1) does
>  not use `-K'.
>   |[ ... ]
>   | I've never used afio but I think the problem is
>   | that cdrecord expects iso images not arbitrary data.
> 
>  eh?  AFAIK, in `-data' mode (which is the default),
>  `cdrecord' simply writes a data-format CD, and does
>  not give a hoot what about the format of the image.
>  e.g., I have CDs that are tar(1) images, albeit I
>  did not burn them and do not know if `cdrecord'
>  or something else was used:  but they do prove
>  data-format and ISO-9660 are not isomorphic.
> 
>  having said that, I concur Patrick should write
>  ISO-9660 (Rockridge) images.  there may be only
>  one file in the ISO-9660 — an `afio' archive —
>  but the containing software format should be
>  ISO-9660, unless there is a Very Good reason
>  to the contrary.
Having lost patience with afio I decided to use tar instead.
> 
> cheers!
> 	-blf-
> -- 
> Experienced (20+ yrs) kernel/software Eng: | Brian Foster   Montpellier,
>  • Unix, embedded, &tc;  • Linux;  • doc;  | blf at utvinternet.ie   FRANCE
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