ITEM: DE6412L

Unable to read volume label from device /dev/rmt0.1



Question:

Env:
  AIX 4.2.1
  RISC 43p-240
  sysback.rte 4.1.1.7 and sysback.rte 4.1.0.1008

Problem:
  Customer creates a fullsystem backup using this syntax
  sysback -xf /dev/rmt0 -T chrp -k mp

  The customer is not able to verify this tape it is failing this way:

  sysrestore -xf /dev/rmt0 -tV -V rootvg

  Unable to read volume label from device /dev/rmt0.1

It turns out the chrp proto files do not put a IBMA into their boot 
image like rspc and rs6k  proto files do

So the setbs.sh and readsbheader both will fail when trying to deterime
if the tape is a bootable tape.

I am temporarly having the customers do this:

The following work-around will allow you to verify a Sysback Tape made
with the 'chrp' proto type, use this until we get a more permanent
fix.

1.  cd /usr/sbin
2.  cp setbs.sh setbs.sh.bak
3.  cp readsbheader readsbheader.bak
4.  vi readsbheader

    Do a search on IBMA

----------------
CHANGE THIS CODE
----------------

       if [ $rc -ne 0 -o "$DUMMY" != "IBMA" ]
        then \# Not a system backup
          runcommand "sbdevice -r $devname" "" $hostname \# rewind
           msg 216 'Unable to read volume label from device %s.' $firstdev >&2
                       cancel 1
       fi

--------------------------------------------------
TO THIS CODE            Comment out all the lines
--------------------------------------------------

\#     if [ $rc -ne 0 -o "$DUMMY" != "IBMA" ]
\#        then \# Not a system backup
\#         runcommand "sbdevice -r $devname" "" $hostname \# rewind
\#         msg 216 'Unable to read volume label from device %s.' $firstdev >&2
\#                       cancel 1
\#               fi

5.  vi readsbheader

    Do a search on IBMA


----------------
CHANGE THIS CODE
----------------

       if [ $rc != 0 -o "$DUMMY" != "IBMA" ]
          then \# Either not bootable or volume 1 is not inserted
               sbdevice -r $devname \# rewind
               msg 108 'There are no boot images on this tape.' >&2
               cancel 1
       fi


--------------------------------------------------
TO THIS CODE            Comment out all the lines
--------------------------------------------------

\#       if [ $rc != 0 -o "$DUMMY" != "IBMA" ]
\#          then \# Either not bootable or volume 1 is not inserted
\#               sbdevice -r $devname \# rewind
\#               msg 108 'There are no boot images on this tape.' >&2
\#               cancel 1
\#       fi


APPENDED by tj on 07/03/97 16:24:
Lee, this is an OK temp fix but definitely not permanent. I need to be
able to identify the boot image on the tape. Otherwise, we get the old problem
when we try to skip the boot images of forwarding the entire tape then
getting I/O errors if the tape is not a system backup. Also Sysback V4
"sysrestore" checks to see if the tape is a bootable backup if there
is no header at the beginning. 

Can you please tell me where there is a chrp system with a boot tape
inserted that I can check out? Or if you wish you can try reading the
image yourself to see if there are any identifiable tags. I dont have
even the level of code installed to support CHRP on my system.

Thanks.

APPENDED by tj on 07/07/97 10:19:
Lee, got a response yet?

APPENDED by lmiller@systape2 on 07/07/97 15:29:

Here is the output from my tests done on mars.aix.dfw.ibm.com

I created three boot images (network boot images)

mksbnetboot -B -k mp -T chrp -d fddi
mksbnetboot -B -k mp -T chrp -d token-ring
mksbnetboot -B -k mp -T chrp -d ethernet

dd if=bootimage.tok.chrp.mp bs=1b count=1 | dd bs=1 count=4 | od -c

0000000  177   E   L
0000003    F
0000004

dd if=bootimage.fddi.chrp.mp bs=1b count=1 | dd bs=1 count=4 | od -c

0000000  177   E   L
0000003    F
40000004

dd if=bootimage.ent.chrp.mp bs=1b count=1 | dd bs=1 count=4 | od -c

0000000  177   E   L
0000003    F
40000004

On the customer's system I was able to verify the tape boot image looked 
this way.

dd if=/dev/rmt0 bs=1b count=1 | dd bs=1 count=4 | od -c

0000000  177   E   L
0000003    F
0000004

So it appears to be constant so far at AIX 4.2.1 using a chrp proto.
Also I have installed all the chrp filesets on the mars system, and yes
fddi, token-ring, ethernet, tape are all supported boot devices using
chrp proto files.

Still probaby need to verify this out with Ausin Boot support 
people on the magic number.

CLOSED by tj on 07/10/97 03:21:
This will be included in \#8 which I will post this morning. 

This is fixed with sysback.rte 4.1.1.8 and 
sysback.trial.4.1.0.1010


Support Line: Unable to read volume label from device /dev/rmt0.1 ITEM: DE6412L
Dated: July 1997 Category: N/A
This HTML file was generated 99/06/24~13:30:16
Comments or suggestions? Contact us