Windchill 10+ will delete log files after 15 days.
Windchill 10.2m020+ will zip the files after 15 days and delete them after 31 days.
These settings can be modified to preserve all log files, but is there really a need to do that. I used to keep all log files until I wnet to 10.0 and let the system purge itself. Moving the log files to a subfolder of logs will not prevent Windchill from deleting them.
You need to ask yourself what value is there in keeping the old log files? The information in tghem is cryptic at best and gives no logging information. Logging information is in the access.log file in the WindchillDS folder.
You can also adjust the 15 and 31 day cutoffs and even get custom handling of old log files by writing a simple delegate in Java.
That said, I suspect the existing 15 and 31 day cutoffs suffice in a whole lot of cases.
You are asking a Creo question in the Windchill section - though these files may have been generated by Creo on behalf of Windchill
These files are outputs of Creo activity. Trail files record actions taken during each Creo session and Dwg_log.out is recording some information about creating file type dwg.
Try using Notepad to read these files.