Physical Log

Hi All, I am running IDS 9.40 on AIX 5.1. and have been getting the following warning over the last week in my online.log: WARNING! Physical Log size 20480 is too small. Physical Log overflows may occur during peak activity. Recommended minimum Physical Log size is 20 times maximum concurrent user threads. I have went to increase my phsical log to 25000KB which is slightly over the 20 time maximum concurrent user threads, but I get the following error message "Physical log size specified is too large." The PHYSDB has 20480KB free so I thought I should be able to increase it with this extra 4520KB with no problem. The strange thing is if I decreased the size of the Physical log to around 5000KB I can increase it back up to 25000KB. I am stuggling to find anything explaining this in Administrator's guide. Thanks in advance.

After further reading I have realised if I run the oncheck -pe command this will tell you how much free space I have in PHYSDB dbspace. Therefore you need to have enough space free to fit your new sized physical log in completely as well as the old log and not just the space difference as I thought. It must then clean the old physical log when Informix restarts. I have found the best way around this is to shutdown Informix change the PHYSFILE parameter in the onconfig file and then restart Informix, this will create the physical log as the new size and there will be no size issues, like the ones you get when trying to increase it in quiescent mode.