Microsoft Exchange Server uses a transactional database architecture. This means that all database transactions are stored in Log files. Exchange versions prior to Exchange 2007 used a 5MB file with a unique naming convention. The log file name is a sequential Hexadecimal number starting with log file E0000001.log. Once the Log File is full of changes the next log file in the sequence is created E0000002.log. Exchange continues to do this until exactly 1,030,000 log files have been created (E00FFFFF.log) and then “HOUSTON WE HAVE A PROBLEM”. Now before we get to the fix, just how big of a deal is this? 1,030,000 is a lot of transaction logs files that can be generated and we should never run out right?. However, some Exchange 2000/2003 Servers have been in production for 10+ years. If we do the math on the number of maximum available logs and divide that by 3650 (10 Years) we can roughly estimate 282 log files a day or 1410 MB of email transactions per day. For smaller organizations this would seem like a significant amount of space on a daily basis considering weekends and holidays when email traffic is lessened. Unfortunately, even smaller Exchange Server shops run 24X7 365 days a years and Exchange is never down and constantly sending and receiving email.
Now, here is some detailed explanations before we all go running and screaming that the sky is falling. These log files are generated per storage group and per server. So, multiple storage groups reduce the possibility of hitting the max. Other activities such as stopping the database and deleting the checkpoint file and all transaction logs will reset the sequence back to E0000001.log. It is not recommended to perform these activities frequently as they can cause issue with backup and restore, they are sometime performed during database maintenance and or recovery.
So what do you do if you hit the max? Thankfully the folks over at Microsoft have already written an article explaining what to do. Check out this link to do some additional reading.
In summary check your log files and event viewer to figure out how much time you can run before action must be taken.Tweet