Re: [Dump-users] Problems restoring on FC6

[Peter V. <pe...@wn...>]

Hello,

I would be grateful for any additional input regarding this problem.  I have
DDS4 tapes created on RH9 (dump 0.4b36) that I am unable to restore
to a newly built PC running FC6 with a new DDS4 tape drive.

My first thought was to assume an incompatabiliy between the dump versions
(dump 0.4b36 verses 0.4b41 for FC6) but Stelian points out below this is 
unlikely.

He does mention differences in the scsi driver :
"However, one piece of the puzzle did change: the scsi tape driver.
 It could be as simple as having different default settings - like
 the read ahead for example - or it could behave differently."

So I'm now trying my third tape drive and I'm seeing a pattern.

I'll insert a tape into the FC6 PC that was created on the RH9 PC
and issue this command :

" mt -f /dev/nst0 fsf 1"

And get back an error      "/dev/nst0: Input/output error"

and in dmesg I get :      "st0: Current: sense key: Medium Error
                                   Additional sense: Unrecovered read error"

So just a basic position of the tape fails. However
"mt -f /dev/nst0 rewind"  yields no error.

The versions of /bin/mt are different.  RH9's is 0.7 and FC6 is 0.9b
but from looking at the man pages for mt, st and the README file
for the mt v0.9b I don't see any significant modifications or default
differences.

What's also very interesting is that if I create multiple dumps on the
FC6 PC I can restore from the FC6 PC.  Positioning the tape
also works.

I'd like to get to the bottom of this - does any one have a suggestion on how
to proceed?

Thanks Pete



----- Original Message ----- 
From: Stelian Pop
To: Peter Van
Cc: dum...@li...
Sent: Thursday, June 14, 2007 2:16 PM
Subject: Re: [Dump-users] Problems restoring on FC6


On Wed, Jun 13, 2007 at 10:01:44AM -0700, Peter Van wrote:
> Hi,
>
> I have many DDS4 dump tapes created on Redhat 9 (dump 0.4b36) and
> have no problem restoring to the same RH9 computer or even to a
> different computer running FC2.
>
> I have just built a new computer with FC6 (dump/restore version 0.4b41)
> and am having limited success restoring tapes to this computer
> that were created on my RH9 computer.
>
> Some tapes restore fine but most do not and fail with :
>
> "Tape read error while skipping over inode 17008
> continue? [yn] "
>
> and the following in dmesg : "st0: Current: sense key: Medium Error
>     Additional sense: Sequential positioning error"
>
> Or I get a "Tape read error on first record" message.
>
> Are there any differences between the versions of dump/restore on
> RH9 and FC6 that could account for this ?

I don't think there are (but you could try compiling 0.4b36 on FC6
just to confirm).

However, one piece of the puzzle did change: the scsi tape driver.
It could be as simple as having different default settings - like
the read ahead for example - or it could behave differently.

Or maybe the tape drive (the hardware) is just less tolerant on tape
errors. Maybe you should try swapping the tape drives just to see...

Stelian.
-- 
Stelian Pop <st...@po...>