IDS Forum

ontape to disk

Posted By: Schmitz, Rob B[EQ]
Date: Thursday, 9 July 2009, at 11:20 a.m.

Good morning IDS folks!

Sorry for the long post, but I have been wrestling with an ontape script for some time now and seem to have hit a brick wall. We currently have 156 instances on 78 servers. We have IDS 7.31 and 9.40 of various levels running on Sun, HP, and AIX. We have successfully used BMC's SQL-BackTrack as our storage manager with onbar for many years. My company decided they no longer want to pay for the BMC license so I need another method for performing database backups. I looked at ISM but it has too many limitations. Some of our instances are over 1 TB and we have many large chunks.

I would love to be able to upgrade to 11.5, but again, the company does not want to spend any resources to upgrade. Their stated goal is to quit using Informix. Although that has been a goal for over ten years, we haven't gotten rid of one app yet. However, that means they won't spend anything to upgrade. By the way, my company is getting rid of SQL-BackTrack for Oracle as well, but rman seems to fill the void fairly well.

I feel that my solution is to use ontape to disk. I searched the IIUG repository and Google and the best I could find was a little script named auto_ontape.ksh, written by Peter Tashkoff in 1998. Because the script was originally written for a tape jukebox, I had to make a few modifications, but it has turned out to be very useful. This script watches the output from ontape and when it sees the prompt to "Please mount tape " it jiggers the link specified in TAPEDEV and issues an echo to serve as the "return". Here is what that script looks like:

----------------------------------------------------------------------
echo

sleep 20

echo "\nThe first file in the series is ${ARCH_FILE}" >> $OUTFILE

while [ `onstat -g ath | grep arcbackup | wc -l` -gt 0 ]
do

sleep 10

if [ `tail -1 $OUTFILE | awk '{print $2}'` = "mount" ]

then

let INCRMNT=INCRMNT+1

ARCH_FILE=${BACKUP_DIR}/${INFORMIXSERVER}_${TIMESTAMP}-${INCRMNT}.Level_${LVL}

touch $ARCH_FILE

chmod 777 $ARCH_FILE

rm -f ${BASE_DIR}/${INST}/links/tape/tapedev

ln -s ${ARCH_FILE} ${BASE_DIR}/${INST}/links/tape/tapedev

echo

echo "\nNew file is ${ARCH_FILE}" >> $OUTFILE

fi
done

echo "\nThe last file in the series is ${ARCH_FILE}" >> $OUTFILE
----------------------------------------------------------------------

Most of the environment variables, including the first ARCH_FILE, are set in the calling script. auto_ontape.ksh is called by:

auto_ontape.ksh | ontape -s -L $LVL >> $OUTFILE 2>> $OUTFILE

The calling script does some instance checking before calling auto_ontape.ksh and it performs some expiration functions afterwards.

This works most of the time. It appears to always work for our 9.40 instances because I set TAPESIZE to 0 and we don't have to worry about multiple backup files. The problem I have is that on the 7.31 instances on which I am testing, the output file gets so many "Please mount tape " messages so quickly that the output file fills the filesystem holding our message files (different from the filesystem holding the backup files). So far, it seems to only do this on Saturday nights. There are no informix cron jobs that are different on Saturday than any other night. I am also investigating if the tape ops folks are backing up the server at that time, but thus far I have not found any reason for this to happen.

I found a reference to this same issue in my Google searches, but I cannot find any reason for it or how to avoid it. I also read that the 2 GB file limit went away in 7.2, but that does not seem to be the case. (I believe it finally went away in 9.x.)

Does anyone have any idea what causes this behavior? Alternatively, does anyone know of a different script that could avoid this problem?

Any help would be greatly appreciated.

Thanks

Rob Schmitz
Embarq Data Management
rob.b.schmitz@embarq.com
www.embarq.com

Messages In This Thread

• ontape to disk
  Schmitz, Rob B[EQ] -- Thursday, 9 July 2009, at 11:20 a.m.
  • Re: ontape to disk
    Art Kagel -- Thursday, 9 July 2009, at 12:25 p.m.
    • RE: ontape to disk
      Schmitz, Rob B[EQ] -- Thursday, 9 July 2009, at 12:50 p.m.
      • Re: ontape to disk
        Art Kagel -- Thursday, 9 July 2009, at 1:03 p.m.
  • Re: ontape to disk
    GUSTAVO TOBARES -- Thursday, 9 July 2009, at 11:44 p.m.
    • RE: ontape to disk
      Schmitz, Rob B[EQ] -- Friday, 10 July 2009, at 8:55 a.m.
      • Re: ontape to disk
        Art Kagel -- Friday, 10 July 2009, at 1:01 p.m.

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