how to ontape to disk

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spender@163.com - 26 Feb 2008 04:19 GMT

Hello:

Environment:
AIX 5.3
IDS 10 FC6

How to use "ontape" command to backup database to file(juse 1G), and
automatic change volume name like vtape.1, vtape.2, vtape.3 etc....

game me some support

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Jack Parker - 26 Feb 2008 12:48 GMT

With v10 you can set TAPEDEV in your $ONCONFIG to STDIO or a disk file name
(full path + file - e.g. /opt/informix/backup/tape). There is also a
TAPESIZE in which you can indicate whatever size you want. I'm not sure why
you would want to change "tapes" at 1GB. ontape will prompt you to change
tapes, I suppose you could use "expect" to watch for that, rename your
tapefile to something and then send a return to ontape - but I don't
understand why you would want to. It might make sense if you were backing
up 2TB of disk to a little 100GB drive and had to swap out occasionally.
But for that sort of thing you really should be using "onbar" and a storage
manager anyway. I would recommend reading the "Backup and Restore Guide".

Note, if you do use "expect", and TAPEDEV=file, you will always backup to
that file, you will need to move the backed up file out of the way (rename
it) and place a new "empty" file in it's place:

mv $INFORMIXDIR/backup/tape $INFORMIXDIR/backup/tape.$n
touch $INFORMIXDIR/backup/tape
n = n + 1

What you might also consider is backing up through a compression program.
Set TAPEDEV to STDIO and then "ontape -s -L 0 | gzip - > backup.gz" (doing
from memory, may have something off there). This will compress your backup
on the fly and make it take less space and run faster. It reduces I/O work
which is typically the bottleneck - but CPU will peak higher.

cheers
j.

Sane ego te vocavi. Forsitan capedictum tuum desit.

-----Original Message-----
From: informix-list-bounces@iiug.org
[mailto:informix-list-bounces@iiug.org]On Behalf Of spender@163.com
Sent: Monday, February 25, 2008 11:20 PM
To: informix-list@iiug.org
Subject: how to ontape to disk

Hello:

Environment:
AIX 5.3
IDS 10 FC6

How to use "ontape" command to backup database to file(juse 1G), and
automatic change volume name like vtape.1, vtape.2, vtape.3 etc....

game me some support

_______________________________________________
Informix-list mailing list
Informix-list@iiug.org
http://www.iiug.org/mailman/listinfo/informix-list

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spender - 26 Feb 2008 14:54 GMT

first thanks:

I want backup database use "ontape -s -L 0" to backup informix database to
disk.
but, If i set TAPEDEV too small, it will prompt user "press Enter to
continue...", and wait for input, (read key)
if I set TAPEDEV too big, it will squander too many disk spaces.

I make a NFS filesystem and mount it to : /home/informix/backup/ <--vtape
file.
I want use "ontape" to backup my database, it create 1G files(rationality),
and when ontape prompt me change tape, I must copy vtape to a new file, just
like: vtape.1, and then press <enter> to continue.,and go on ......etc

Question:
User must be a normal unix user, and can input shell command,
I wan't do it though program or shell scripts or "crontab", user only need
click mouse from web, and wait for user input <enter> not need, shell script
will copy vtape file to vtape.$n......

hehe. Chinese user, and opretor can't do any unix command. !!!!!

use STDIO as TAPEDEV, I never do it, try it later....

> With v10 you can set TAPEDEV in your $ONCONFIG to STDIO or a disk file
> name
[quoted text clipped - 53 lines]
> Informix-list@iiug.org
> http://www.iiug.org/mailman/listinfo/informix-list

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Art S. Kagel (Oninit) - 26 Feb 2008 15:05 GMT

First, setting TAPESIZE larger than you need will not waste disk. IDS
will not write out the full maximum size of the file to TAPESIZE in any
case, only the size actually needed rounded up to the next TAPEBLK
blocksize. However, if your OS can handle an archive file large enough
to hold all of your chunks and any physical log records written during
the archive period, then you can set TAPESIZE to zero (0) and ontape
will continue to write to the file until the filesystem fills up or the
OS returns a 'too large' error before prompting for a new tape file.

Art S. Kagel
Oninit

> first thanks:
>
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>
>

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TBP - 26 Feb 2008 20:41 GMT

Humm,

Loads of bits of information here :

1. I would strongly NOT recommend setting TAPEDEV to STDIO.

Try it ... set TAPEDEV to STDIO and ... run ontape -s -L 0! Be quick if
you want to restore it :S. Use ontape -s -L 0 -t STDIO

Sort of thing that will catch you out late at night on a 9600 baud
connection!

2. Version 11 (I know) has the ability to have TAPEDEV set to a
directory, sort of "set and forget" ... obviously beware of full
filesystems etc. etc.

3. There are LOADS of scripts out there which will do "what you ask",
but ...

> First, setting TAPESIZE larger than you need will not waste disk. IDS
> will not write out the full maximum size of the file to TAPESIZE in any
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>
> ===========================================================================================

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