Thanks for your reply. You described the behaviour I was expecting. This is why I wonder about the file sizes.
The service was running wihtout any productive actions at that night. It reads some configuration files (of another tool) and (mostly) logs to smart inspect. The second file (log-2013-08-20-17-00-00.sil) and the second to last file (log-2013-08-21-06-00-06.sil) have both 1380 entries. I can't see any crucial differences in the files (dates changes, entries seems to be the same)...
If there isn't any known behaviour like this, may I contact your Support via email ?
Ok, I compared the (2) files. First I exported them to HTML. Both files have a size of 331 KB. Using a file comparison tool, you can see many differences in dates. I couldn't find differences that could cause that behaviour in the file size, for example:
Then I made a hex compare to the files. Now we can see there is a lot more data in the second file. Here's the example:
Thanks and regards,