ESEutil is a useful tool because it can operate in many modes. However, each mode performs different functions, with limitations or caveats. Table A shows the different functions of ESEutil.

The way each of these functions is executed within the utility is to use a cryptic MS-DOS-like command structure as the parameter qualifier. For example, in order to run the defragmenter portion of the utility, an administrator would run "ESEutil /d <database name> [options]" and so on. For additional information on ESEutil, please refer to the GOexchange FAQ on our Web site--Microsoft ESEutil at http://www.goexchange.com/faq_GEvsMStools4.html.

We aren't going to attempt to cover all the potential pitfalls with ESEutil, however, there are a few major issues regarding ESEutil to keep in mind.

There are times when it's appropriate to use ESEutil on its own, however, a complete maintenance process includes the combined use of specific ESEutil and ISinteg commands, as well as other steps that must be undertaken. ESEutil is a very powerful tool, and if the commands are entered improperly or in an incorrect order, the results can be catastrophic.

The ESEutil command structure can be very confusing, and at times misleading. Changing one letter in the command structure executes a completely different utility function, and the results to an Exchange database can be disastrous. Below are a few of the many different available modes and options for ESEutil, each of which can have very different results on a database. NOTE: For brevity we haven't included entire command statements.

"ESEutil /d" will defragment the designated database, and is a fairly straightforward mode of operation that's commonly used. Running a manual offline defragmentation is only part of the process that should be completed in order to keep the databases healthy. Many administrators run ESEutil on a database to remove deleted items and regain white space, then mistakenly assume that by doing so the process is complete.

Performing this task, however, doesn't check or address issues that may exist within the mail data itself, and it won't fix the links between the tables of an ESE database. The database now contains a higher percentage of errors, warnings, and minor inconsistencies than it did prior to defragmentation. NOTE: Running ESEutil repeatedly without implementing a complete offline maintenance process is a certain recipe for disaster.