From: fuzzy@obelix.ncs.mainz.ibm.com (Thomas Braunbeck/131000)
Subject: Re: How can I get mksysb use 2 tapes? Do I need diff block size?
Date: Fri, 02 Oct 92 17:20:58 GMT
Reply-To: braunbec@Mainz.IBM.de
Organization: IBM Germany, AIX Support Germany

In article <1992Oct2.130804.12884@magnus.acs.ohio-state.edu>, mcover@magnus.acs.ohio-state.edu (Mark Coverdill) writes:
|> In article <1992Sep24.194501.13559@ncar.ucar.edu> fredrick@acd.acd.ucar.edu (Timothy Fredrick) writes:
|> [deleted info about multiple tapes]
|> >
|> >Should I be setting the block size on the tape device to something other
|> >than 0.  We have it set to 0 so we can read/write tapes produced on Sun
|> >SPARCstations.
|> >
|>
|> I followed the thread about the fix so that you can use multiple tapes
|> but many moons ago it was said that a 'mysysb' tape will only properly
|> restore if the blocksize was set to 512.  Is this no longer the case
|> under 3.2.x?

Here is one answer (PSP record MKSYSB, ask you local SW service
for all the other PSPs available):

                   **************************

                   *    SUBSET   MKSYSB     *

                   **************************

    This subset contains information regarding the AIX Version 3,
    Release 2 for the RISC System/6000.  This information will help
    with a potential problem with mksysb that causes the backup to
    be uninstallable for users who have AIX 3.2 with out U403173.

************************************************************************

*                 C H A N G E    S U M M A R Y

************************************************************************

      1.  92/09/09   INSTALLATION INFORMATION

      2.  92/09/09   DOCUMENTATION CHANGES         No Entries

      3.  92/09/09   GENERAL INFORMATION           No Entries

      4.  92/09/09   SERVICE RECOMMENDATIONS


************************************************************************

*             I N S T A L L A T I O N    I N F O R M A T I O N         *

************************************************************************

        This section contains helpful solutions and hints to
        problems that MAY BE encountered during installation.

************************************************************************

    There is a potential problem with mksysb that causes the backup
    to be uninstallable.  If the system is at 3.2 and the mksysb is
    make with a blocksize other than 512 they might have problems
    reading the tar image on the tape.  This will give them an error
    saying the .fs.size file is missing or contains invalid information.
    This problem has been corrected with U403173.  Please be sure
    customers have U403173 installed.


************************************************************************

*           S E R V I C E     R E C O M M E N D A T I O N S

************************************************************************

          This section contains information for the service of
          a problem.  What to do to fix it and/or make it work.

************************************************************************

          1.  92/09/17  USER'S AFFECTED:  All who install using 8MM
                                          system image backup tapes.

          2.  92/09/17  PROBLEM DESCRIPTION:

                        MKSYSB 8MM Tape Work Around


          3.  92/09/17  ACTION:

                        MKSYSB 8MM Tape BLOCK SIZE Recovery


                     Here is a work around that will be handy
                     for all who install (or help others install)
                     using 8mm system image backup tapes. It's the one
                     about the 8mm tape block_size being wrong when a
                     system has been backed up, using the mksysb process

               Supplies:

               Install/Maintenance Diskette of the desired level.
               Enough temporary space to restore the Install/Maintenance
               diskette.

               The steps:  (As root)

               *  Create a temporary directory for restoring the
                  Install/Maintenance diskette.

                       mkdir tmp

               *  Change your current working directory
                  to that directory.

                       cd tmp

               *  Restore the Install/Maintenance diskette.

                       restore -xvq

               *  Edit the file called startup2.

                  Search for the string 512.  There is a comment
                  in the file which says, "Make sure that all
                  tape devices are at 512." A couple of lines later,
                  there is a chdev command which sets the block_size
                  to 512. Change the 512 to 1024 or whatever your
                  block_size was when you made the system backup.

                  Save your changes to the file.

               *  RE-create the diskette with the following
                  command, typed from the directory where the
                  diskette was restored.

                       find . -print | backup -ivqp

               *  Boot as usual from diskette.  The system backup
                  tape will be useable, provided the change
                  was made correctly.
--

Best regards,   Thomas Braunbeck
AS Software Service AIX, Germany

        All the opinions expressed are my own and
        do not necessarily reflect those of IBM

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