Re: [Bug-tar] Possible tar bug

[bocek . pavel]

I used to make one whole archive at once, backuping whole folder, but it tends 
to be problematic when some tape becomes bad (I have to make whole archive 
again than).

So now I backup files in the folder alphabetically from A to Z (and numbers 
first) because I can append from previous good record not having to start from 
beginning with tens of GB. I started with some older tar version from Ubuntu 
repository (1.20 or so) and:

sudo tar -cMf /dev/st0 some_path/1*

Then continued with letters up to G. It stucked with our error so I tried again:

sudo tar -cMf /dev/st0 some_path/G*

from last record. Still the same problem. Than I tried files starting with H, 
it took IIRC another one or two tapes (which worked fine so definitelly not 
tape problem). After it I tried G again with no success. Upgraded to latest 
Ubuntu repository tar (1.21 I think), nothing, than manually installed latest 
tar from source and discovered which file is problematic, still not able to 
append this single one.

I can try only the 14GB file on two fresh tapes when I'll get to my NAS to 
discover whether it's problem with exotic archive format. But I did not change 
anything in config files nor used special options so it had to start with this 
format automatically.

> ------------ Původní zpráva ------------
> Od: Paul Eggert &lt;<a href="mailto:address@hidden";>address@hidden</a>>
> Předmět: Re: [Bug-tar] Possible tar bug
> Datum: 27.12.2010 08:34:26
> ----------------------------------------
> On 12/26/2010 05:07 PM, <a href="mailto:address@hidden";>address@hidden</a> 
> wrote:
> > I used -cMf for the very first tape, than I continued with -rMf for adding 
> > new
> files, shouldn't this make the whole huge archive in correct format?
>
> Yes, it should.  However, we need to be able to reproduce the problem.
> I can reproduce it if I don't use -cMf for the very first tape, or
> if I use an unusual option like -o or -H ustar (possibly in TAR_OPTIONS).
> I can also "reproduce" it if we assume that you have a bad tape, that
> somehow passed the checksum tests.  But I can't reproduce it otherwise.
> So it sounds like we are still at a loss as to why you are observing
> the symptoms that you do.
>
>
>