New E0Xtmp.log behavior after you apply Exchange 2000 SP2

After you apply Exchange 2000 Service Pack 2 (SP2), the behavior of the temporary log file changes. This article summarizes how temporary log files are generated and used for the following products:

• Exchange Server 4.0, 5.0, and 5.5
• Exchange 2000 and Exchange 2000 SP1
• Exchange 2000 SP2 and later

Temporary Log Generation in Exchange Server 4.0, 5.0, and 5.5

Exchange Server stores the most current transactions in the Edb.log file. When the size of the Edb.log file reaches 5 megabytes (MB), Exchange Server creates a file called Edbtmp.log to accept incoming transactions, and then renames the Edb.log file Edb00001.log. After Exchange Server renames the Edb.log file, the program renames the Edbtmp.log file as Edb.log. This process is repeated each time the Edb.log file size reaches 5 MB. The log files are built up when Exchange Server creates more and more transactions, but the Edbtmp.log file only exists for a short time.

For more information about log file generation in Exchange 4.0, 5.0, and 5.5, click the following article number to view the article in the Microsoft Knowledge Base:

Temporary Log Generation in Exchange 2000 Server and Exchange 2000 SP1

In all versions of Exchange 2000 (including Exchange 2000 Release to Manufacturing [RTM]), you can view the temporary log file in the log file location for the Exchange 2000 storage group. The following file name is an example of the log file name, where X is the number of the storage group: The following list shows how the log file names appear in Exchange 2000:

• E00tmp.log
• E01tmp.log
• E02tmp.log
• E03tmp.log

NOTE: Exchange 2000 Server Standard Edition supports only one storage group, so only one log file with the file name E00tmp.log is created.

Exchange 2000 RTM and Exchange 2000 SP1 store the most current transactions in the E0X.log file. When the E0X.log file size reaches 5 MB, Exchange 2000 RTM and Exchange 2000 SP1 create a file named E0Xtmp.log to accept incoming transactions, and the E0X.log file is renamed E0X00001.log. After the E0X.log file is renamed, the E0Xtmp.log file is renamed E0X.log. This process is repeated each time the E0X.log file size reaches 5 MB.

Temporary Log Generation in Exchange 2000 SP2 and Later

In Exchange 2000 SP2, Extensible Storage Engine (ESE) begins to create a new E0Xtmp.log as soon as the current E0Xtmp.log is renamed to E000001.log or to the next available lGeneration number. It does not begin to create a new E0Xtmp.log when the E0X.log is full. The temp log is generated by ESE with a low priority background thread while transaction log rollover occurs. These files are deleted by ESE when all stores in the storage group are dismounted or when IS is stopped. These files are used as a working storage area and can be anywhere from 1 MB to 5 MB large. These .tmp files are also used to store incoming transactions while the current log file is being renamed to the next lGeneration number.

Exchange 2000 SP2 has been modified to correct Exchange 2000 performance issues that occur when ESE switches to a new log file.

Function of the E0Xtmp.log file in Backup and Restore Operations

In all versions of Exchange 2000, the E0Xtmp.log file is empty; you can safely ignore it. Exchange 2000 automatically deletes the file when all stores in one storage group are dismounted appropriately. The E0Xtmp.log file is not backed up to the tape during an online backup of Exchange 2000 storage groups.

If you perform a disaster recovery operation (for example, after a power outage), an E0Xtmp.log may appear on the server, even though the databases in the storage group are not mounted because of a non-standard shutdown operation. In Exchange 2000, an E0Xtmp.log file has no data in it. Therefore, the E0Xtmp.log file has no function in data recovery during either an online restore operation or an offline restore operation of Exchange 2000.