I'm using Load Generator to initialize data on Exchange 2007 and seeing this strange behavior. Circular logging is enabled on all SGs on my exchange server but it still creates large number of log files during user initialization. I expected that not to happen. The reason I have cir. logging on because I'm seeing loadgen filling log disk with lots of log files during initialization phase and prevent me from creating more users on my mailstore volume. Any suggestion how to handle this.

I continued with circular logging on for my simulation test and that appears to be working fine. It doesn't generate new transaction log files. Looks like user/mailbox initialization by LoadGen is doing something different. I couldn't find any option in config. XML file that I can customize for circular logging. What I've noticed that durung initialization LoadGen generates lots of log files compare to simulation phase and this puts limits on number of users/mailboxes that can be created. Is initialization phase not going thorugh Exchange store engine?

I think I was too quick in concluding that circular logging doesn't work in Exchange 2007. It does work but is bit different that Exchange 2003. This article describes mechanics of circular logging in Exchange 2003 - Clearing the confusion around Exchange Server circular logging. It says that in Exchange 2003, MSExchangeIS only creates 4 transaction logfiles are used at a time before circling back to 1st one. But what I noticed in Exchange 2007 that there are more files generated in the folder, including E**, tmp, E**tmp, etc. Understanding Transaction Logging: Exchange 2007 Help articles says that IS engine would overwrite a log files when its datat are commit to DB. So I think there is no specific number. It probably dependes upon when IS engine get chance to commit to edb file. May be microsoft can tell more about it. In my testing I saw about 20-30 files while I was initializing 1500 users. With another testing involving initialization of 2500 users, I can see more than 40 files.