Ensure that you have adequate hard disk capacity for your servers running Exchange 2000. You should have enough space on your hard disk to restore both the database and the log files.

It is possible to have a backup large enough that it cannot be restored it to its original location. For example, a Normal backup performed once a week, plus six days of Differential backups, might require more disk space during a restore than your server has available. Whether the restore requires more disk space than you have available depends on how many log files are generated during a week. For example, a server generating 2,000 log files in a week amounts to 10 GB of log file space, in addition to the space required for the database.

Performing normal backups on a daily basis reduces the amount of space required to restore your Exchange 2000 databases. This is because normal backups delete the transaction log files up to the time that the backup is performed.
Therefore, if you need to restore your Exchange 2000 databases, perform normal backups on a daily basis to ensure that you do not have to restore more than one day's worth of log files.

Also, you should never let your database drive (the hard disk containing the .edb and .stm files) become more than half full. Although a database drive that is half full results in unused disk space, it can still reduce extended server downtime for the following reasons:

1. With your database drive half full, you can restore databases faster than with a drive that is entirely full (especially if the file system is fragmented).
2. With your database drive half full, you can perform offline defragmentation and other maintenance duties on the same physical disk, instead of copying databases over to a maintenance server (which takes much longer than copying database files to a temporary directory on the same physical hard disk).
3. With your database drive half full, you can back up a copy of the databases to the same physical disk before you restore them.

For this reason, it is recommended that you move or copy the current database and log files before restoring a database. For more information about moving or copying database or log files, see ôCopying or Moving the Existing Version of the Database Files That You are Restoringö in Part 3 of this document.

Note Given the large size of the average database, copying your most current database to a different physical disk drive or to another server is likely to add several hours to your downtime. However, if you have sufficient local disk space on the same physical drive, you can simply move the current database files to another folder using a command prompt or Windows Explorer before performing the restore.

The information in this article applies to:

• Microsoft Exchange Server 2003 Enterprise Edition
• Microsoft Exchange Server 2003 Standard Edition
• Microsoft Windows Small Business Server 2003, Premium Edition
• Microsoft Windows Small Business Server 2003, Standard Edition
• Microsoft Exchange 2000 Server