Informix: ontape -a error: Log backup to device '/dev/null' not allowed

[Andrey Pevnev]

Hello!

I want to enable automatic logical logs backup on informix IDS, but ontape -a gives this error:

Performing automatic backup of logical logs.
Logbackup failed - Log backup to device '/dev/null' not allowed


Program over.

LTAPEDEV is set to /dev/null in onconfig

I found a technical case on IBM site with the same problem http://www-1.ibm.com/support/docview.wss?rs=0&q1=Log+backup+to+device+%27%2fdev%2fnull%27+not+allowed&uid=swg21141581&loc=en_US&cs=utf-8&cc=us〈=en

But I've restarted Informix many times, it doesn't help :(

Maybe you have some ideas?

Informix version:
Informix Dynamic Server Version 7.31.UD6W5
HP-UX
B.11.11 U 9000/800

Thanks!

[Tommy Brown]

Andrey,
You must change the LTAPEDEV to a valid tape device and restart the Informix server.
Tommy

[Andrey Pevnev]

But I don't want to backup logical logs.
On another HP machine LTAPEDEV is set to /dev/null and everything is ok. I can't understand why it can't work on this machine...

[Tommy Brown]

Andrey,
Change TAPEDEV to /dev/null
not LTAPEDEV and try the ontape again.. LTAPEDEV must not be /dev/null
Tommy

[Tommy Brown]

Sorry,
I just double checked.. Neither should be /dev/null.
You can send them to a file, then delete the file.. This was a change I think at 7.31 we could at 7.24, not since..
Tommy

[Rainer von Bongartz]

Andrey

I don't see what you want to accomplish.

you wrote

I want to enable automatic logical logs backup on informix IDS

and later

but I don't want to backup logical logs.

Please tell us what your goal exactly is

Regards
Rainer

[Steve Lewis · Accepted solution]

I think you actually want the logs to self-clear without needing an ontape. When LTAPEDEV is set to /dev/null you never need to run ontape -a or ontape -c because it regards the logs as always backed up. i.e. at the end of every log switch the engine automatically sets the flags back to U-B----

You may have an unprintable character in the onconfig file at that line which is causing it to mis-read it.

Completely delete the entire LTAPEDEV line using dd in vi, then re-enter

LTAPEDEV /dev/null # Log tape device path

Also put /dev/null next to TAPEDEV

Then bounce it again. Run ontape -s -L 0, then change TAPEDEV back to your normal device and bounce it again.

[Andrey Pevnev]

Yeah, Steve, that's what I want! :)

Ok, I will set LTAPEDEV to /dev/null and will no run onatpe -a, let's see will logical logs overflow or not. Thanks!

[Brian Butscher]

Andrey,

You can write your logical logs to /dev/null using 'ontape -c' not 'ontape -a'. Just change your LTAPEDEV /dev/null. By the way,
when you change your tape device for either LTAPEDEV or TAPEDEV you don't need to bounce IDS as these two parameters are read when you perform a database backup or logical log backup.

Regards,

Brian

[Brian Butscher]

Andrey,

I should have said that the 'ontape -c' or ontape -a is not needed. Your logical logs will continuously backup to /dev/null, which is what you want. We have two of our dev server running this way, no problems.

Regards,

Brian

[Andrey Pevnev]

Thanks, Brian!

[rmueller58]

I am running IDS 7.31 fwiw, You CAN run the
TAPEDEV to /dev/null, LTAPEDEV still runs transactions logs, in order maintain record rollback transactions have to go to log. I don't think there is a way around and personally I'd not recommend it.
My nutsack would be hanging on my door if something happened and a database got some whacked data.. ontape takes very little CPU or memory but could well be a butt saver, from personal experience in having to recover from a mirror crash recently YOU DO want archives in addition to your exports. disk and tapes are cheap compared to getting 500 pissed off educators breathing down your throat.

You can set your transaction logging and archive to run to an NFS mount, Tape or local disk, but IMHO don't go with out..