SUMMARY: GNU-TAR & Dump to Remote Tape Drive Server

Many thanks to all the folks that responded. In particular, big thanks
go to Michael Miller, who "hit the nail right on the head". 

Additionally, apologies for my posting having the "clearly wrong" syntax
at the front and centre (ie,
--file=Server:/dev/rmt/on/tarball_name_here_duh.tgz) and the less-wrong
syntax buried at the end of my posting. Alas, this syntax was not the
issue at the heart of the matter.


Something smells fishy in the land of the default compile for GnuTar
1.13 on Sparc-Solaris2.6...


My binaries were obtained by downloading the source for GnuTar 1.13 ;
running "./configure --prefix=/opt/gnutar" and then "make ; make
install". This proceeded smoothly and with no obvious problems, other
than the "tar - grandchild..." errors when attempting the remote tar
dump with this binary.


To fix the Problem: I used a different binary version of GnuTar -
namely, a binary package downloaded from www.sunfreeware.com by the name
of "tar-1.12.lfs.3-sol26-sparc-local-alpha.gz" -- which is an
alpha-release of GnuTar 1.12 with "Large File Support" patched in --
particularly relevant for Solaris 2.6 it appears, allowing GnuTar 1.12
to deal with files larger than 2 gigs for this OS, as stated in the
included readme (see below).

When I used the identical syntax with this different version of GnuTar,
things worked swimmingly.

Illustration follows:

CLIENT# rsh SERVER mt status

 HP DDS-3 4MM DAT tape drive:
    sense key(0x0)= No Additional Sense   residual= 0   retries= 0
    file no= 5   block no= 0
 
 CLIENT# ./tar -c -v -z --file=1.2.3.4:/dev/rmt/0n ./*
 ./tar
 
 CLIENT# !-2

 rsh SERVER mt status
 HP DDS-3 4MM DAT tape drive:
    sense key(0x0)= No Additional Sense   residual= 0   retries= 0
    file no= 6   block no= 0


So. Happy days. The thing "works", although I'm still not thrilled that
the default build of GnuTar on my box totally fails to work for remote
dumps. Examination of the docs ; google and the other usual places fails
to clarify this little detail.

Hope this is all relatively clear and of some use to other folks,
despite the semi-rambling non-brevity.


-Tim Chipman



===README from GnuTar 1.12 with LFS Support====

ftp://alpha.gnu.org/gnu/  (See the README file there)

The README for this tar states:

GNU `tar' 1.12.lfs.3 is an unofficial port of GNU `tar' 1.12 to Large
File Summit (LFS) environments like Solaris 2.6 that rely on integer
system types longer than `long'.  Ordinary GNU `tar' 1.12 cannot handle
files larger than 2 GB when compiled in such environments.  This port
addresses that problem.  Please send bug reports specific to this
unofficial version of GNU `tar' to <eggert@twinsun.com>.




====ORIGINAL POSTING FOLLOWS====

Subject: Q: GNU-TAR & Dump to Remote Tape Drive Server
   Date: Wed, 18 Jul 2001 13:00:20 -0400
   From: Tim Chipman <chipman@ecopiabio.com>
    To:  sunmanagers@sunmanagers.org

Hi all,

likely a very trivial thing but it is driving me up the wall, so I
resort to asking for help.

I'm trying to use GnuTar ver 1.13 on a Sparc-solaris 2.6 box to dump a
tarball archive to another sparc-solaris-2.6 machine which has a 4mm 
DAT tape drive. Alas I'm getting the error:

tar (grandchild): Cannot open archive server:/dev/rmt/0n/tarball.tgz:
I/O error
tar (grandchild): Error is not recoverable: exiting now

(see below for full output)


I've already confirmed that rsh is setup and working ; I've tested doing
more-or-less the same thing using the non-gnu tar in conjunction with
"dd" - and they work OK. (So no problems with write-protected tape, etc
etc.)  I've read the GNUTar manual, done plenty of google searches.. all
to no avail.  Oh yes: I've also confirmed that there is a link from
/etc/rmt -> ../usr/sbin/rmt, since gnutar manual indicates that /etc/rmt
must exist for this to work.

Ultimately I'm hoping to use this procedure for dumping large (4-10 gig)
files from our database server to tape for "disaster recovery" purposes.

I guess I *can* do this via the tar / dd approach ; however I'm under
the impression that gnu-tar will do a better job. (possibly this is
incorrect?)

Any assistance is greatly appreciated.


-Tim Chipman



---paste---

Confirm RSH Works:
==================

client# rsh server mt status
HP DDS-3 4MM DAT tape drive:
   sense key(0x0)= No Additional Sense   residual= 0   retries= 0
   file no= 1   block no= 0



NON-GNU_TAR WAY:
================

client# tar cvfb - 20 ./* | rsh server dd of=/dev/rmt/0n obs=20
a ./bin/ 0K
.
..etc....
.
3291+0 records in
84249+1 records out

client# rsh server mt status
HP DDS-3 4MM DAT tape drive:
   sense key(0x0)= No Additional Sense   residual= 0   retries= 0
   file no= 2   block no= 0
   

GNU_TAR_ATTEMPT:
================


client# 

/opt/gnutar/bin/tar -c -v -z --file=server:/dev/rmt/0n/tarball.tgz ./*
./simple_use_note.txt
./tar
sh: unknown host
tar (grandchild): Cannot open archive helios:/dev/rmt/0n/tarball.tgz:
I/O error
tar (grandchild): Error is not recoverable: exiting now

also tried with:

--file=server.ip.address.here:/dev/rmt/0n/tarball.tgz
--file=server.ip.address.here:/dev/rmt/0n

(made no difference ; the presence of the "sh: unknown host" error
message made me initially wonder if the "server" name wasn't resolving
.. but AFIK using the exact IP of the thing should make this a non-issue
(?) ).



---endpaste---