The size of mail databases and the resources they consume on servers are important concerns for many companies. The larger the mail databases, the more difficult it is for the administration team to manage the backup and maintenance of the environment. Additionally, users see a reduction in performance on the server and on their workstation as they attempt to access the databases because of increases in processor, memory, disk Input/Output (I/O), and bandwidth requirements. It is important to understand that simply maintaining the size of the mail database does not ensure the best user or server performance. In addition to the large size of the mail database, the number of documents in a view -- particularly the Inbox -- can also degrade performance.
Companies are facing increasingly stricter regulations on the retention of electronic messages for legal reasons, and therefore, it is a delicate balancing act to determine the appropriate course of action to control mail database size. This article focuses on the use of quotas to assist in maintaining reasonable mail databases sizes. It is also important to implement the proper mail journaling and archiving features to comply with legal requirements beyond the simple implementation of quotas.
The IBM Lotus Domino environment provides a number of different configuration settings to allow flexibility in the implementation of quotas. The basic configuration of mail quotas is to set a maximum size limit and a warning threshold, allowing users to send, to receive, and to manage messages even after they have reached their quota. It does not, however, let them effect changes on their mail database that increase the size, such as saving new sent messages or drafts, copying in new messages, or adding new design elements to the mail database. A more advanced configuration involves settings that limit the router's ability to send or receive new messages for as long as the mail database exceeds its quota.
A mail database must be under the intended quota prior to setting the quota, or the quota is not applied. For instance, if the mail database is at 125 MB and you attempt to set a 100 MB quota on the database, the quota is not applied until the mail database is reduced to less than 100 MB. You receive errors, but you can still increase the size of your database.
Understanding the elements of database quotas
This section reviews the elements of the database quotas process, including the standard configuration for mail database quotas and enhancing the enforcement of quotas through the use of the mail router. Additionally, information is provided on the size limits of mail databases, the elements of the database, such as soft deletes and compaction that affect the users' experience, and messages in the server log that assist the administration team in understanding which mail databases have reached the warning threshold or quota.
Standard configuration for mail database quotas
By default, when a quota has been placed on the mail database, the router continues to route mail for the user, including the sending/receiving of messages. This ensures that a user can use his mail database to view new incoming messages and to respond to them accordingly. The user cannot, however, save sent messages, save draft documents, add new calendar entries, or create new database elements, such as views.
Enhanced configuration with mail routing
You can configure the Lotus Domino environment using a Server Configuration document so that the router limits users' ability to have messages routed to their mail database. Users can still send messages but, again, they cannot perform functions that add to the database size, such as saving sent messages or drafts. You can customize these routing settings to meet the needs of your organization.
Database size limits
The maximum size tested for a Lotus Domino database is 64 GB, which actually is limited by the underlying operating system. This is the maximum size; a practical size is based on the environment in which the mail file resides. The size of servers with respect to operating system, processor, memory, data storage, and so on dictates the true maximum size. For further information, including the impact of large Inbox sizes on server performance, refer to the developerWorks Lotus article, "Best practices for large Lotus Notes mail files."
Soft deletes and reducing the mail database size
When soft deletes are enabled on a mail database (which is the default for mail files based on the release 7 mail template), deleting messages does not immediately reduce the size of the mail database. Messages remain in the mail database for the period that soft deletes are set (by default, messages are set to expire after 48 hours). To delete a message immediately, you must open the Trash folder for the mail database and either select a message and click the Delete Selected Item button or click the Empty Trash button to remove all messages.
Messages in the LOG.NSF pertaining to quotas
When a database reaches certain thresholds pertaining to the database quotas, the following messages are placed in the Miscellaneous Events view in LOG.NSF for the server (and also display when a database is opened):
- "Cannot allocate database object - database would exceed its disk quota."
This does not prevent the user from accessing the database; it simply stops the user from adding any elements to the database that increase its size if no space is available.
- "Warning, database has exceeded its size warning threshold."
Simply warns the user that he is close to exceeding his limit and allows him an opportunity to reduce the size of the database prior to receiving the previous warning.
Setting quotas on the mail database
This section discusses the different options available to the messaging administration team in configuring quotas on a mail database. These options include leveraging policies at the time of registration and/or manually after the mail database has been created.
Setting quotas at registration through a policy
When creating users within a Lotus Domino environment, you typically leverage registration policies to simplify the registration process, and the Registration Policy document contains a section to govern mail database quotas.
The first option is to set the actual database quota, which is the maximum size that the database can attain before quota errors are sent to users. The second setting is the warning threshold for the mail database, which triggers warning messages to users. It is important to set a reasonable warning threshold (typically 75-90 percent of the quota) so that users have sufficient time to reduce the size of their mail database before hitting the quota. If the warning threshold is too close to the quota, it is possible that one message could trigger both the threshold warning and the over-quota actions. For more information on configuring the registration policy, refer to the "Creating a registration policy settings document" topic in the Lotus Domino 7 Administrator Help.
To locate these settings, open the Domino Directory in the Lotus Notes client. In the Policies\Settings view in the Configuration folder, click the Add Settings button. Select Registration from the button drop-down list. In the Registration Settings document, select the Mail tab. In the Advanced Mail Options section, enable the Set database quota and Set warning threshold options, filling in the appropriate values (see figure 1). Click Save and Close to close the Registration Settings document.
Figure 1. Advanced Mail Options section of Registration Settings document
Setting quotas through the Register Person process
When registering a user through the Domino Administrator client, you can configure the mail quota and warning threshold in the Register Person dialog box. If the Advanced option is selected, the Mail tab displays on the left navigator; click it to see the dialog box shown in figure 2. Select the Set database quota and Set warning threshold options and fill in the appropriate values. After the user is registered, the quota is applied.
Figure 2. Register Person dialog box
Setting or changing quotas after a mail database has been created
To set or change quotas on mail databases, follow these steps:
- In the Domino Administrator client, click the Files tab, and locate the mail directory.
- Select one or more mail databases, and then in the Tools area, click Database and select Quotas.
- In the Set Quotas dialog box, select the "Set database quota to" option and enter the quota value.
- Select the "Set warning threshold to" option and enter the warning threshold value. See figure 3.
Figure 3. Set Quotas dialog box
- Click OK to continue; the new quota is applied to the mail database.
User experience with quotas
When users reach the threshold or maximum quota for their mail database, they see error dialog boxes that require them to take steps to reduce the size of their mail database.
Over threshold warning
When mail databases have a warning threshold set, the following error displays when the database is opened or the user tries to save a draft or new sent message:
"Your mail file has exceeded the warning size threshold of 51200 Kb.
You should delete messages, empty the trash and compact your mail file or contact your Administrator for help."
The experience in IBM Lotus Domino Web Access is less obtrusive; the client has an indicator that identifies the size of your mail database, and the color is changed to red to indicate the warning threshold (see figure 4).
Figure 4. Lotus Domino Web Access warning threshold indicator
Over quota warning
When mail databases have exceeded their size threshold, the following error displays when users attempt to send a message that will be saved:
"Unable to write to your mail database which is currently 84492 KB. Saving this message would exceed the disk quota of 76800 KB by 7694 KB.
You should delete messages, empty the trash and compact your mail file or contact your Administrator for help."
If a user attempts to send a message using the Lotus Domino Web Access client, the following error message displays:
"Domino Web Access Warning
Problem: - Unable to write to database because database would exceed its disk quota.
Solution: Click here to close this window and return to the main window."
The user must follow the compacting steps described below to reduce his mail database and avoid receiving quota warnings.
Compacting the mail database
After users delete messages or empty the trash, they must compact their mail database on the server. Typically, the Compact task is run on the servers during off-hours, so the users must manually compact their database. The following sections review the manual compaction process and the server-based Compact task.
User compaction of the mail database
Manual compaction of the mail database on the server adjusts its size to move it under the quota. You can do this manual compaction by completing the following steps:
- In Lotus Notes, choose File â Database â Properties to open the Database Properties box.
- Select the Info tab, and then click the % used button to see the amount of space that can be recovered (see figure 5).
- Click the Compact button to reduce the size of the database.
Figure 5. Database Properties Information tab
After the Compact task is complete, you can use your mail database (the Compact option is available only through the full Lotus Notes client).
When transaction logging is enabled, the manual compaction actions do not function in the same way as when transaction logging is disabled. Specifically, you must force the server to ignore white space in the database when enforcing quotas by selecting the "Check space used in file when adding a note" option in the Quota enforcement field on the Transactional Logging tab of the Server document (see figure 6).
Figure 6. Transactional Logging tab
Setting compacting on the server
Configuring the Compact task on the server is the easiest way to manage mail databases and to avoid the manual steps outlined earlier. The following steps outline the process of setting the Compact task through the Server Configuration document:
- In the Domino Directory, open the Servers\Programs view in the Configuration folder, and then click the Add Program button.
- Complete the Program document with the appropriate values, examples of which are shown in figure 7. Some tips to follow:
- The Command line field can contain many options; the example parameter, -B -S 10, compacts databases in-place that have greater than 10 percent white space.
- Set the Run at times and Days of week fields to avoid other administrative tasks.
- Click Save & Close to initialize the Program document.
Figure 7. Example of Compact Program document
The -B switch changes the DBIID. If transaction logging is used for backups, use this switch only before the full backup schedule (once a week). Running Compact with no switch (default setting) does not change the DBIID; it can run nightly if transaction logging is used, reclaiming white space, but not reducing file size.
For more information on the switches available when implementing the Compact task, refer to the "Compact options" section in the Lotus Domino 7 Administrator Help.
Using the router to enhance quota enforcement
To restrict the routing of mail for users who have exceeded their quota, you can modify some configuration settings with respect to the router to ensure more stringent enforcement.
Setting router parameters to enforce quotas
To enforce quotas from the router, follow these steps:
- In the Domino Directory, open the Servers\Configurations view in the Configuration folder to edit the Configuration document for the mail server on which you want to control the quotas.
- In the Configuration Settings document, select the Router/SMTP - Restrictions and Controls - Delivery Controls subtabs (see figure 8.) There are a number of options available within this section of the Configuration Settings document. To determine the appropriate options for your requirements, refer to the "Setting quota controls for the Router section" in the Lotus Domino 7 Administrator Help.
Figure 8. Sample Configuration document
- Click Save & Close.
The change takes effect after the next Router configuration update, which you can perform by entering
tell router quit on the server console. After the router has been terminated, type
load router. The router now leverages the configuration changes to enforce quotas.
User experience with router-enforced quotas
Even with the router-enforced quotas, when users reach the threshold or maximum quota for their mail database, they see error dialog boxes that require them to take steps to reduce the size of their mail database. The user difference is the further re-enforcement of receiving an email message that notifies them that they are over-quota.
Over threshold warning
When a mail database exceeds its warning threshold, users receive an error when they open their mail database, and then find a message with the subject Quota Warning Report as shown in figure 9.
Figure 9. Quota warning report email
The message, an example of which is shown in figure 10, contains information about the current status of their mail database.
Figure 10. Example of Quota Warning Report
Over quota error
Likewise, when a mail database exceeds its set quota, the user receives an error when he opens his mail database. In the mail database, the user finds the message with the subject Over Quota Error as shown in figure 9.
The message contains information about the current status of the mail database, an example of which is shown in figure 11, when the "Deliver Anyway (Donât obey quotas)" option is selected. (The "What should you do?" section notes that new messages will continue to be delivered.)
Figure 11. Example of Quota Error Report when "Deliver Anyway..." option is selected
If the Configuration document is set to "Non deliver to originator," then the message is not delivered to the mail database, but the Quota Error Report in figure 12 is delivered to the recipient. (The "What should you do?" section notes that new messages will not be delivered and a Non-Delivery Report will be delivered to the sender.)
Figure 12. Example of Quota Error Report when âNon deliver to originatorâ option is selected
The sender receives a Non-Delivery Report in her mail database with Mail Router as the sender and the subject DELIVERY FAILURE as shown in figure 13.
Figure 13. Example of Non-Delivery Report
Case study for implementing quotas
It is critical to understand that every environment has unique requirements, and therefore, it is difficult to outline a set of standards or recommendations that can be applied to all companies. The following case study is intended to assist you in outlining a successful plan for deploying quotas.
XYZ Company has growing storage requirements for mail databases. Recently, the IT team worked with the legal department to deploy a message journaling system to capture all messages that are transferred through the environment. The team determined that automated archiving of messages for the users was not going to be a part of the solution and that user management of mail databases was the most appropriate course of action. They also decided to implement Lotus Domino-based quotas to minimize database size.
The IT team conducted an assessment of the company's current usage patterns, determining that the average mail database size was 234 MB across the environment. There were four distinct groups of sizes that were identified:
- Less than 150 MB
- 150-250 MB (50 percent of the population)
- 250-400 MB (40 percent)
- 400 MB-13 GB (10 percent)
The average message size was relatively small, but a number of large presentations (with an average size close to 10 MB) flowed through the environment.
The IT team went to the lines of business to develop a plan for implementing quotas to minimize the risks to the user communities. The lines of business felt that implementing quotas to restrict the flow of messages through the router was not acceptable and would create risk within the business. They agreed that it was important to work with the users who represented the biggest risk (greater than 500 MB) on a one-on-one basis and that the IT team would furnish the lines of business with the names of these users.
Additionally, the lines of business agreed to quotas for their users and to a warning threshold of 90% of the quota, a four-tiered approach to be implemented as follows:
- 250 MB (225 MB warning threshold) for all new users and users currently under 210 MB so that the implementation of the quotas does not immediately place them within the warning threshold.
- 400 MB (360 MB warning threshold) for all users with mail databases between 210-340 MB.
- 600 MB (540 MB warning threshold) for all users with mail databases between 340-600 MB; it was determined that users in this category would be notified on an individual basis, and that if they exceeded the 540 MB warning threshold, they should receive the warning messages.
- X+100 MB (X+50 MB warning threshold) for all users over 600 MB; their quota is set to 100 MB over their current mail database size with a warning threshold of 50 MB over their current mail database size.
The lines of business agreed that any movement from the lower quota to a higher quota required business justification and approval of the management. A nominal charge-back fee would apply to the change in quota.
The IT team established a registration policy that placed a 250 MB quota (225 MB warning threshold) on all new users registered. The team classified all users on the servers into the previous categories and communicated the timeline for rolling out the new quota system. After the new quotas were applied and were in effect for six months, the IT team and lines of business met with the legal department to ensure that the quotas were appropriate for the company.
Controlling the size of mail databases is a vital function of managing an IBM Lotus Domino environment. The implementation of quotas can significantly enhance the administration teamâs ability to control the size of mail databases. This article has outlined the steps necessary to implement quotas and the impact on the user community. As with the implementation of any new policies, it is important to ensure that the implementation is done in an effective, unobtrusive manner. Also, always refer to the IBM Lotus Domino Administrator's Help database to ensure the information presented here is applicable to your environment.
- developerWorks Lotus article, "Best practices for large Lotus Notes mail files"
- developerWorks Lotus article, "Sizing your IBM Lotus Domino mail servers"
- Lotus Domino 7 Administrator Help
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