Logical logs on filesystem (VXFS)

I use a continous backup "ontape -c" on a filesystem and one time/day I do an "ontape -s -L 0", to reduce the among of space used in the filesystem I first kill the "ontape -c" process, copy the backup-logfile, compress it, clear the original (with a ">" in Unix) and start "ontape -c" again. Before I start again ontape, the file is zero bytes long, after start he takes the original size again ! What's the reason of this ? Informix holds the size of the file ? Is there some action to do before the restart of ontape ?

Bernard Bernard wrote: > I use a continous backup "ontape -c" on a filesystem and one time/day I do > an "ontape -s -L 0", to reduce the among of space used in the filesystem I > first kill the "ontape -c" process, copy the backup-logfile, compress it, > clear the original (with a ">" in Unix) and start "ontape -c" again. Before > I start again ontape, the file is zero bytes long, after start he takes the > original size again ! What's the reason of this ? Informix holds the size of > the file ? Is there some action to do before the restart of ontape How do you kill ontape -c ? If you do it by kill -9 ontape has no chance to perform ending operations. In this case you should use the break signal (kill -2). Are you sure nobody uses the file (fuser) when you make the ">" ? Is the size of your file system file the same as a logical log file? Then it could be just one logical log. Regards -- Helmut Leininger Bull AG / Vienna Open Systems Support Email: h.leininger@bull.at helmut.leininger@bull.net This opinion is mine and not necessarily that of my employer. No guarantees whatsoever.

Logical logs get backed up to LTAPEDEV. Your ONCONFIG also indicates the size of LTAPEDEV using the parameter LTAPESIZE. During a logical log backup using "ontape -c", the file specified by LTAPEDEV will continue to grow until it reaches LTAPESIZE. You will then be prompted to "change your tape". The scenario you describe seems to imply that you are headed for problems, because LTAPESIZE is not large enough to hold the logs created during the day. What's probably happening is that the previous day's ontape -c has filled LTAPEDEV to LTAPESIZE and is waiting at the prompt "change your tape". So, when you come to do your change the tape procedure (copy-compress-initialize), all logs have NOT been backed up. Consequently, as soon as you start ontape -c again, the pending logs get backed up, filling LTAPEDEV to LTAPESIZE and then waiting for you to "change your tape". The trouble is, in the near future, all your logs are going to get to the "Used, but not backed up" state, bringing your instance to a grinding halt. You probably have to do your "copy-compress-initialize" process more often than daily or increase LTAPESIZE. Rudy Bernard Bernard wrote: > I use a continous backup "ontape -c" on a filesystem and one time/day I do > an "ontape -s -L 0", to reduce the among of space used in the filesystem I > first kill the "ontape -c" process, copy the backup-logfile, compress it, > clear the original (with a ">" in Unix) and start "ontape -c" again. Before > I start again ontape, the file is zero bytes long, after start he takes the > original size again ! What's the reason of this ? Informix holds the size of > the file ? Is there some action to do before the restart of ontape ?

Rudy Fernandes wrote: > > Logical logs get backed up to LTAPEDEV. Your ONCONFIG also indicates the size > of LTAPEDEV using the parameter LTAPESIZE. > > During a logical log backup using "ontape -c", the file specified by LTAPEDEV > will continue to grow until it reaches LTAPESIZE. You will then be prompted to > "change your tape". > > The scenario you describe seems to imply that you are headed for problems, > because LTAPESIZE is not large enough to hold the logs created during the day. > What's probably happening is that the previous day's ontape -c has filled > LTAPEDEV to LTAPESIZE and is waiting at the prompt "change your tape". So, when > you come to do your change the tape procedure (copy-compress-initialize), all > logs have NOT been backed up. Consequently, as soon as you start ontape -c > again, the pending logs get backed up, filling LTAPEDEV to LTAPESIZE and then > waiting for you to "change your tape". > > The trouble is, in the near future, all your logs are going to get to the > "Used, but not backed up" state, bringing your instance to a grinding halt. > > You probably have to do your "copy-compress-initialize" process more often than > daily or increase LTAPESIZE. OR switch to using the ALARMPROGRAM to backup each logfile to disk as it fills. See my package utils3_ak for both a shell script and an executable that can do this. Art S. Kagel > Rudy > > Bernard Bernard wrote: > > > I use a continous backup "ontape -c" on a filesystem and one time/day I do > > an "ontape -s -L 0", to reduce the among of space used in the filesystem I > > first kill the "ontape -c" process, copy the backup-logfile, compress it, > > clear the original (with a ">" in Unix) and start "ontape -c" again. Before > > I start again ontape, the file is zero bytes long, after start he takes the > > original size again ! What's the reason of this ? Informix holds the size of > > the file ? Is there some action to do before the restart of ontape ?