Windows Server 2003 Maintenance Made Easy (Continued)

Another major disk issue is caused by drive fragmentation. Whenever files are created, deleted, or modified, Windows Server 2003 assigns a group of disk clusters depending on the size of the file. As file size requirements fluctuate over time, so does the number of groups of clusters assigned to the file. Even though this process is more efficient when using NTFS, the files and volumes eventually become fragmented as the files do not reside in a contiguous location on the disk.

As fragmentation levels increase, disk access slows (see Figure 1). The system must use additional resources and time to find all the cluster groups in order to use the file. To minimize the amount of fragmentation and give performance a boost, the administrator should use the built-in Disk Defragmenter or a third-party tool such as Diskeeper to defragment all volumes.

The Domain Controller Diagnostic (DCDIAG) utility provided in the Windows Server 2003 Support Tools is used to analyze the state of a domain controller (DC). It runs a series of tests, analyzes the state of the DC, and verifies different areas of the system, such as

• Connectivity
• Replication
• Topology integrity
• Security descriptors
• Netlogon rights
• Intersite health
• Roles
• Trust verification

DCDIAG should be run on each DC on a weekly basis or more often if problems arise.

Monthly Maintenance
WINS, DHCP, and DNS are three low-maintenance network services prevalent in most environments, but as with any other database, it's important to regularly check these databases to keep them running as efficiently as possible.

WINS uses the Extensible Storage Engine (ESE) to store system entries, and these entries are being updated, added, or deleted continuously. Over time, the WINS database can contain a lot of unused space due to the abundance of changes. As a result, the database should be compacted to regain the unused space and to enable the system to service the environment faster and more efficiently. Windows Server 2003 dynamically compacts the database, but offline compaction is required periodically as well.

The first step in WINS database compaction is to make sure that WINS has been backed up successfully. With the exception of the first backup, WINS backups happen in Windows Server 2003 automatically. To back up the WINS database, select Mappings, Back Up Database within the WINS Manager and then specify a location for the backup files. Click OK and WINS will then back up its database automatically every 24 hours.

If the WINS database ever becomes corrupted, simply stop and restart the WINS service. If WINS detects corruption, it will restore the most recent backup automatically. If WINS does not detect the corruption, the administrator can force a restore by selecting Mappings, Restore Database from the WINS Manager.

WINS is also designed to compact its databases automatically when they become too large. However, the administrator should periodically compact them manually. For large Windows Server 2003 environments with more than 1000 systems, Microsoft recommends compacting the database manually once a month. To compact the WINS database manually, open a command prompt window and change the directory path to show %SystemRoot%\Systems32\wins and then type NET STOP WINS. Next type the command JETPACK WINS.MDB TEMP.MDB and then type NET START WINS.

DHCP maintenance is less complex than WINS maintenance. The DHCP database and related Registry entries (i.e., DHCP.mdb, DHCP.tmp, J50.log, J50#####.log, and J50.chk) are backed up every 15 minutes automatically by default. Also, the DHCP database is compacted at specific intervals automatically. You can use the same procedure to compact the DHCP database.

Similar to WINS and DHCP, DNS operates efficiently on its own and requires very little intervention or maintenance. However, one way to maintain DNS in medium to large environments is to set aging and scavenging. Depending on the number of updates and the number of records, DNS can potentially experience problems with removing stale records. Although this doesn't necessarily cause performance degradation or resolution problems in smaller networks, it might affect larger ones. As such, it's important to periodically scavenge this database. Aging and scavenging are not enabled by default, so they must manually be enabled by selecting Action, Set Aging/Scavenging within the DNS snap-in. (Be sure the appropriate server is highlighted first.) Then check the box within the Server Aging/Scavenging Properties window and set the appropriate intervals, as shown in Figure 2.

Another often-overlooked monthly task is testing uninterruptible power supplies (UPSs). These devices protect the system or group of systems from power failures (such as spikes and surges) and keep the system running long enough after a power outage so that an administrator can shut down the system gracefully. Administrators should follow the manufacturer's test guidelines at least once a month.