Jon,

On Fri, Jan 07, 2005 at 05:45:16PM -0500, Jon LaBadie wrote:
> On Fri, Jan 07, 2005 at 03:40:12PM -0500, Brian Cuttler wrote:
> > 
> > samar 24# mt -f /dev/sdlt2 blksize
> > 
> >  Recommended tape I/O size: 131072 bytes (256 512-byte blocks)
> >  Minimum block size: 4 byte(s)
> >  Maximum block size: 16777212 bytes
> >  Current block size: Variable
> > 
> > I am using /dev/sdlt2 link to /dev/rmt/tps1d4nrns - no rewind, non-byte swap
> > device. I am no longer using the trailing 'v' device which would normally
> > provide variable length blocks.
> > 
> 
> Brian,
> as you were using the 'v', might the data on the tapes have been written with
> some > 32K block size?  All of your dd's seem to fail after the header.
> 
> How about trying a couple of mt fsf # to some file in the middle (on the
> no rewind device), then do dd's with bs=128k and/or bs=1024k and/or bs=16384k.

That is the odd thing, I am using the fixed block device, /dev/sdlt2
(a link) was modified prior to relabeling the tape and I was sure to
use the link throughout the process, I know I didn't use the variable
device by mistate.

A restore from further into the tape.

samar 5#  /usr/local/sbin/amrestore /dev/sdlt2 samar /usr5/amanda
amrestore:   0: skipping start of tape: date 20050108 label SAMAR07
amrestore:   1: restoring samar._usr5_amanda.20050108.0
amrestore: read error: I/O error
samar 6# 
gzip: stdin: unexpected end of file

Fixed length device showing this time.

samar 6# mt -f /dev/sdlt2 rewind
samar 7# mt -f /dev/sdlt2 blksize

 Recommended tape I/O size: 131072 bytes (256 512-byte blocks)
 Minimum block size: 4 byte(s)
 Maximum block size: 16777212 bytes
 Current block size: 32768 byte(s)

But wait ! actually looking (for a change) at all of the words I notice...

-->  Recommended tape I/O size: 131072 bytes (256 512-byte blocks)

Yah, I'm gonna try again with this new block size.


---
   Brian R Cuttler                 brian.cuttler AT wadsworth DOT org
   Computer Systems Support        (v) 518 486-1697
   Wadsworth Center                (f) 518 473-6384
   NYS Department of Health        Help Desk 518 473-0773