[ale] CPIO!

[Dow Hurst]

Tar will stop only if the tape is compressed.  If you don't use
compression then tar can skip to the next block and recover.  I don't
know anything about cpio or afio so can't say anything about them.  I
will be looking at Amanda later this summer.  If robustness of the
archive *and* compression are requirements for you then tar probably
isn't your solution.  Any comments on Amanda or Arkeia?  Arkeia was just
too expensive when I got a quote for ~20 SGI stations, a few Win95
boxes, and a linux box.  They quoted $12000 in license fees!!!  We just
don't have that kind of money ever on a grant budget.
Dow

James CE Johnson wrote:
> 
> Dow Hurst wrote:
> 
> >Why not alias "txj" to 'tar xf - | bzip2' and use that?  Just do the
> >alias in /etc/profile or /etc/cshrc so all your shells inherit it.
> >
> Can a bzip2 archive recover from corruption somewhere in the middle?
>  I'm pretty sure gzip can't.  I suppose if it does a block-wise
> compression where each block is independent of the preceeding blocks
> then you could recover.
> 
> The only point I was trying to make is that if you compress your entire
> archive and your decompressor can't recover if there is mid-stream
> corruption then your entire archive is lost.  If you compress each file
> individually and your archiver can recover from mid-stream corruption
> then you only loose those files "under" the corruption.
> 
> Someone made an earlier comment about the history of tar vs cpio.  I
> just ran across this in the tar info page:
> 
>      If anyone knows why `cpio' was made when `tar' was present at the
>      unix scene,
> 
>    It wasn't.  `cpio' first showed up in PWB/UNIX 1.0; no
> generally-available version of UNIX had `tar' at the time.  I don't
> know whether any version that was generally available _within AT&T_ had
> `tar', or, if so, whether the people within AT&T who did `cpio' knew
> about it.
> 
>    On restore, if there is a corruption on a tape `tar' will stop at
> that point, while `cpio' will skip over it and try to restore the rest
> of the files.
> 
> >
> >Dow
> >
> >Stuffed Crust wrote:
> >
> >>On Thu, Jun 14, 2001 at 04:54:52PM -0400, James CE Johnson wrote:
> >>
> >>>Now if someone would fix tar such that 'tar xz' is something other than
> >>>'tar xf - | gzip', that would be great.
> >>>
> >>um, like 'tar xj; is equivalent to 'tar xf - | bzip2'?
> >>
> >> - Pizza
> >>--
> >>Solomon Peachy                                    pizzaATfucktheusers.org
> >>I ain't broke, but I'm badly bent.                           ICQ# 1318344
> >>Patience comes to those who wait.
> >>    ...It's not "Beanbag Love", it's a "Transanimate Relationship"...
> >>--
> >>To unsubscribe: mail majordomo at ale.org with "unsubscribe ale" in message body.
> >>
> >
> 
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__________________________________________________________
Dow Hurst                   Office: 770-499-3428
Systems Support Specialist  Fax:    770-423-6744
1000 Chastain Rd.
Chemistry Department SC428  Email:dhurst at kennesaw.edu
Kennesaw State University         Dow.Hurst at mindspring.com
Kennesaw, GA 30144
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