Trying to recover Secondary using ontape -l

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antzz - 29 Oct 2003 20:58 GMT

I have an HDR setup (IDS 7.31 on SCO UNIX). As an experiment, I
shutdown the Secondary for the weekend. I have logical log backups
every hour on the Primary using a disk file. On the first workday, I
restarted the Secondary and it went into Fast Recovery(Sec) mode. The
message log prompted me to start recovery from tape (i.e. the logs have
already cycled on the Primary). I redirected the first disk file backup
to my LTAPEDEV device and started ontape -l. It stated that I have to
roll forward using log number 21270 and prompted me to insert another
tape? Now, I know that the disk file I have contains log number 21270.

Why isn't ontape detecting this???

Is there a trick or special way to recover from disk files?

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Jonathan Leffler - 30 Oct 2003 08:18 GMT

> I have an HDR setup (IDS 7.31 on SCO UNIX). As an experiment, I
> shutdown the Secondary for the weekend. I have logical log backups
[quoted text clipped - 5 lines]
> roll forward using log number 21270 and prompted me to insert another
> tape? Now, I know that the disk file I have contains log number 21270.

You've got that information in the records you keep, haven't you?

> Why isn't ontape detecting this???

You have to be very careful - it doesn't expect the device name to
change during recovery, IIRC. So, normally, you have two windows
open. One runs the recovery using a symbolic link as the 'tape
device'. The other is used to 'switch tapes' by repointing the
symlink to the correct new log file each time the recovery asks for
the next 'tape'.

> Is there a trick or special way to recover from disk files?

Yes; see above.

Note that it is a good idea to practice these things - preferably
moderately often and in a variety of states (level 0, level 1, level 2
backups, with and without extra log files), just to make sure you have
the recovery process sorted out completely.

Signature

Jonathan Leffler #include <disclaimer.h>
Email: jleffler@earthlink.net, jleffler@us.ibm.com
Guardian of DBD::Informix v2003.04 -- http://dbi.perl.org/

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antzz - 30 Oct 2003 14:10 GMT

Thanks for your reply.

This is exactly what I was doing - two sessions open, with the other
one doing the "switching" of tapes, while the other one is doing the
ontape -l.

My question is why ontape is prompting me to insert another tape when I
have the right "tape" in the current log tape device. I know I have the
right log file - why is ontape asking me if I want another one? I don't
have any other log backup that contains log number 21270.

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mosserp@wellsfargo.com - 30 Oct 2003 19:14 GMT

When you transferred the log file over to the secondary, did you make sure
that permissions are 660, owner:group = informix:informix? You might need
to check directory permissions, too, to make sure that 'ontape' can access
the file and symlink.

HTH,
Paul Mosser

-----Original Message-----
From: owner-informix-list@iiug.org
[mailto:owner-informix-list@iiug.org]On Behalf Of antzz
Sent: Thursday, October 30, 2003 6:10 AM
To: informix-list@iiug.org
Subject: Re: Trying to recover Secondary using ontape -l

Thanks for your reply.

This is exactly what I was doing - two sessions open, with the other
one doing the "switching" of tapes, while the other one is doing the
ontape -l.

My question is why ontape is prompting me to insert another tape when I
have the right "tape" in the current log tape device. I know I have the
right log file - why is ontape asking me if I want another one? I don't
have any other log backup that contains log number 21270.

sending to informix-list

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