For at least the next few years, many Exchange administrators will likely continue to support Exchange Server 5.x installations. Although Exchange 5.5 is seemingly stable and well established, problems can occur if you don't properly set up and maintain this system. To look for potential problems, I've developed the Exchange 5.5 Reality Check. In this article, I cover the first part of the Reality Check, which entails creating sound policies and procedures; monitoring the system's health and performance; updating, documenting, and configuring the system; tweaking performance; and preparing for an eventual Exchange 2000 Server migration. In a future article, I'll address the second part of the Reality Check: Exchange security concerns.
Creating Policies and Procedures
Although hardware and software are important, minimizing downtime must start with creating the necessary policies and procedures. Here are several important policies and procedures that you should implement in your organization:
- Create a policy that says administrators shouldn't aggravate a problem by making random changes if they don't know the problem's cause.
- Create a policy that says administrators should plan ahead for the deployment of service packs, updates, and hotfixes. Applying hotfixes on a whim should be strictly forbidden.
- To avoid restoring mailboxes that users might have accidentally deleted, create a procedure in which administrators don't delete mailboxes right away. Instead, administrators should rename and hide them. Placing a standard character string such as zz_ in front of the display name will cause the mailboxes to appear in the same area in the address list. After a mailbox has been inactive for 30 to 60 days, an administrator can delete it.
- Create a policy that says administrators should follow the principle of least permissions. They should assign only the Exchange and Windows permissions necessary to accomplish the task at hand.
- Create a policy that says unscheduled downtime isn't permitted unless a disaster occurs. Create an accompanying procedure in which administrators must notify the user community 7 to 10 days before any scheduled downtime.
Monitoring the System's Health and Performance
After you create sound policies and procedures, you need to regularly monitor your system's health and performance. If managing the Exchange servers is your responsibility, you should have a checklist of daily tasks you need to accomplish. You might be pleasantly surprised that this checklist can be fairly short. For example, here's my checklist of daily tasks:
- Perform a backup (preferably a full normal backup) of the private and public Information Stores (ISs).
- Scan the System and Application event logs for events that signal problems and events that signal typical operations, such as completion of online maintenance. Web Table 1 (http://www.exchange
admin.com, InstantDoc ID 27483) lists the events that are important in Exchange 5.5.
- Check the disk space on all server disks.
- Check the Message Transfer Agent (MTA) and Internet Mail Service (IMS) queues for stalled messages.
- Make sure that your virus scanning software has the latest virus signatures and scanning engine. Review the event logs to confirm that signatures are being downloaded and that scans are being completed.
Two of my daily tasks are checking the queue lengths and checking the amount of free disk space. However, queue lengths can quickly increase and the amount of free disk space can quickly decrease, so checking them only once a day might not be enough. To avoid any problems, you can use Windows 2000's or Windows NT 4.0's Performance Monitor counters to continually monitor queue lengths and free disk space and generate an alert if any selected counters stray outside a preconfigured limit. The article "Keep Tabs on Exchange Server," March 1999, http://www.exchangeadmin
.com, InstantDoc ID 5033, describes how to set up Performance Monitor counters.
Figure 1 shows a sample Exchange Alerts Properties dialog box for monitoring an Exchange server named HNLEX01. For each Exchange server you want to monitor, you must decide which queues to monitor. Web Table 2 shows a list of the counters that I recommend monitoring. The threshold values in Web Table 2 might have to be adjusted depending on how high your Exchange server's activity level is.
In the Exchange Alerts Properties dialog box, you need to set the monitoring frequency in the Interval option at the bottom of the dialog box. The default interval for polling the data is 5 seconds, but this interval is too short for this type of data. A value of 60 to 120 seconds will place less burden on your network and Exchange servers.
If you want to monitor free disk space, you must enable the logical disk performance counters. To do so, open the command shell window (click Start, select Run, enter cmd.exe, then click OK) and type
diskperf y
for NT 4.0 or type
diskperf yv
for Win2K.
Updating, Documenting, and Configuring
You can save yourself a lot of headaches by getting your Exchange and Windows systems up-to-date, then documenting those systems. You can also make a few quick configuration changes that will make your job a little easier.
Updating. If you're using Exchange 5.5, Standard Edition (Exchange 5.5/S), make sure that your private and public ISs don't approach 16GB, which is the maximum IS size for that edition. If your IS sizes are approaching 16GB, strictly enforce mailbox storage limits or consider upgrading to Exchange 5.5, Enterprise Edition (Exchange 5.5/E).
I recommend that you have the latest version of the OS and Exchange service packs installed on your Exchange 5.5 servers. The latest service pack for Exchange 5.5 is Service Pack 4 (SP4). In addition, Microsoft has released several hotfixes since SP4. You can find SP4 and the hotfixes at the Microsoft Download Center (http://
www.microsoft.com/download). For earlier hardware, check to see whether flash upgradable BIOS updates are available for that hardware. If you support many similar servers, standardize on the BIOS revisions for servers and RAID controllers; this standardization can make troubleshooting problems much easier.
You should install Exchange-aware antivirus software (e.g., Symantec AntiVirus/Filtering for Microsoft Exchange, Sybari Software's Antigen for Microsoft Exchange) on your Exchange servers if you haven't already done so. Picking different antivirus solutions for your Exchange server and your desktop machines is a good practice. Having different virus engines and signatures scanning for viruses reduces the risk of having a virus sneak onto your Exchange server.