RE: IDS 9.40: Logical Logs - how do I direct to /dev/null

Hi, right. Though these different approaches will cause different behaviour. IDS checks the string value of LTAPEDEV onconfig file parameter. If this is found to be "/dev/null" on UNIX (or "nul" on Windows), then the server makes a note of this and will not do any backup of logical logs. That means when a log change happens, the completed log will be immediately marked as backed up (i.e. it is eligible for cyclical overwriting). No further activity is necessary, especially no ontape command needs to be run to get the log (marked as) backed up. If LTAPEDEV is something different from the above strings, then a normal log backup will have to happen in order to get the log marked as backed up (and eligible for cyclical overwrite). IDS does not check whether the LTAPEDEV value is a (symbolic) link to "/dev/null" (or "nul"). Therefore a log backup needs to be done ("ontape -c" or "ontape -a"). With the link the data of that log backup will go to /dev/null and the log will never be restorable. But it needs to be actively backed up. (Without this log backup you will eventually run into a "logs are full" situation which usually puts vehement brakes on your system ...) Regards, Martin -- Martin Fuerderer IBM Informix Development Munich, Germany Information Management owner-informix-list@iiug.org wrote on 05.04.2005 21:57:19: > Another trick is to set LTAPEDEV to the pathname of a symbolic link. > That way you can change the link without having to update $ONCONFIG and > bounce the engine. For example, you could set LTAPEDEV to /dev/rmt/logs, > which could be a symbolic link to a tape device (e.g. /dev/rmt/0u). > Then, if necessary, you could change /dev/rmt/logs to point to /dev/null > instead. > > John > > -----Original Message----- > From: owner-informix-list@iiug.org [mailto:owner-informix-list@iiug.org] > On Behalf Of Art S. Kagel > Sent: Tuesday, April 05, 2005 9:54 AM > To: informix-list@iiug.org > Subject: Re: IDS 9.40: Logical Logs - how do I direct to /dev/null > > Adam Bradley wrote: > > Hi, > > > > I am running IDS 9.40 with HP-UX 11.11. On my test > > server, in $ONCONFIG I want to be able to have the > > Logical logs writing to /dev/null but the engine won't > > let me do this. > > > > I know I could do this in earlier versions of Informix > > and it's been a while since I've touched this stuff. > > > > Can I write logical logs to /dev/null and if so how? > > > > Thanks, > > Adam > You either have to bounce the engine after changing LTAPEDEV or use > onmonitor to change it. CHanging the file does not modify the version > of > LTAPEDEV that's in shared memory which is the one that the engine will > use > to decide whether to clear the logs or wait for someone to back them up. > > Onmonitor will change the file AND the shared memory version. > > Art S. Kagel > > sending to informix-list sending to informix-list