Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cornell!batcomputer!itsgw!steinmetz!uunet!wpg!russ
From: russ@wpg.UUCP (Russell Lawrence)
Newsgroups: comp.unix.questions
Subject: Re: reading dump tape with bad spots
Message-ID: <1086@wpg.UUCP>
Date: 10 Feb 89 21:04:25 GMT
References: <1084@wpg.UUCP> <472@avsd.UUCP>
Organization: WP Group, POB 306, Metairie, LA 70004
Lines: 30

> In article <1084@wpg.UUCP> I wrote:
> >Does anyone know of any PD dump/dumpdir/restor programs persistent 
> >enough to skip over bad spots on tape?  

In article <472@avsd.UUCP>, childers@avsd.UUCP (Richard Childers) writes:
> No, but I know of a few ways to test for bad spots on tape, if it's something
> you've got the time and energy to be interested in.
> 
> Caveat - testing for errors takes time, you almost have to do the dump twice
> and compare results before you can be *really* sure. The following methods
> represent a half-hearted approach to verification...

This is good advice.  Unfortunately, I'm trying to recover files from a 
dump tape that was perfectly good a year ago when I made the dump, but 
got chewed up a little last week in my tape drive...  thanks to some 
dirty rollers.  As a result, the tape is now useless given the inability 
of dump to recover.  

I'm still hoping that someone will suggest a recovery procedure that will
bail me out.  Nevertheless, the experience has convinced me that I 
should abandon dump/restor and opt instead for ctar or pax.... given
their ability to skip over bad spots.

If I knew more about dump headers, I suppose I could hack something out 
that could look for the appropriate file on the tape (ie inode number) 
and retrieve the data.  Any comments?  

-- 
Russell Lawrence, WP Group, New Orleans (504) 443-5000
{uunet,killer}!wpg!russ