Microsoft Exchange Server 2010 : Using Public Folder Databases (part 2) - Setting Public Folder Database Limits

Setting Public Folder Database Limits

Storage limits are designed to control the amount of information that users can post to public folders. As with mailbox databases, users who exceed the designated limits might receive warning messages and might be subject to certain restrictions, such as the inability to post messages.

Because public folders help users share messages, documents, and ideas, they're an important part of any Exchange organization. Over time, however, public folders can become cluttered, which reduces their usefulness. To minimize clutter, you can set an age limit on items that are posted to public folders. Items that reach the age limit expire and Exchange Server removes them permanently from the public folder.

When you set the age limit, keep in mind the type of information stored in the related public folders. For example, if you have a public folder database for general discussion and file sharing, you might want the age limit to be a few weeks. However, if you have a public folder database for projects, you might want the age limit to extend throughout the life of the project, which could be months or years.

The age limit and the deleted item retention are two separate values. Deleted item retention is designed to ensure that postings and documents that could be needed in the future aren't prematurely deleted. When retention is turned on, deleted items are retained for a specified period before they are permanently deleted and might also need to be backed up before being permanently deleted, depending on the settings you've used. If you have backups, you can recover deleted items from backups.

The age limit applies to deleted items as well. If a deleted item reaches the age limit, it's permanently deleted along with other items that have reached their age limit.

To set the storage limits, age limits, and deleted item retention for a public folder database, follow these steps:

1. In the Exchange Management Console, right-click the public folder database, and then select Properties.

2. In the Properties dialog box, click the Limits tab, as shown in Figure 2. Use the following options to set the limits:

   • Issue Warning At (KB) Sets the size, in kilobytes, of the data that a user can post to the public folder database before a warning is issued. The warning tells the user to clean out the public folder database.

   • Prohibit Post At (KB) Sets the maximum size, in kilobytes, of the data that a user can post to the public folder database. The restriction ends when the total size of the user's data is under the limit.

   • Maximum Item Size (KB) Sets the maximum size, in kilobytes, for postings to the database.

   • Warning Message Interval Sets the interval for sending warning messages to users whose total data size exceeds the designated limits. The default interval is daily at 1 A.M.

   • Keep Deleted Items For (Days) Sets the number of days to retain deleted items. An average retention period is 14 days. If you set the retention period to 0, deleted postings are retained only if you select the next option and then retention is only until the database has been backed up. If a database is backed up, you can recover postings only by restoring them from backups.

   • Don't permanently Delete Items Until The Database Has Been Backed Up Ensures that deleted items are archived into at least one backup set before they are removed.

   • Age Limit For All Folders In This Public Folder Database (Days) Sets the number of days to retain postings in the database. Postings older than the limit are automatically deleted.

     

     Figure 2. Use the Limits tab to set the storage limits, age limits, and deleted item retention for a public folder database.

     Caution

     If you set an age limit, be sure that all users who post to the public folder know about it. Otherwise, they'll be surprised when data is removed, and they could lose important work.

3. Click OK to save the settings.

In the Exchange Management Shell, you can set limits for public folder databases using the Set-PublicFolderDatabase cmdlet. Example 2 provides the syntax and usage. You can enable or disable database maintenance using the –Background-DatabaseMaintenance parameter.

Example 2. Using Set-PublicFolderDatabase to set limits

Syntax

Set-PublicFolderDatabase -Identity PublicFolderDatabaseIdentity
[-AllowFileRestore <$true | $false>]
[-BackgroundDatabaseMaintenance <$true | $false>]
[-CircularLoggingEnabled <$true | $false>]
[-CustomReferralServerList ReferralCost]
[-DeletedItemRetention NumberDays]
[-DomainController DCName]
[-EventHistoryRetentionPeriod TimeSpan]
[-IssueWarningQuota Limit]
[-ItemRetentionPeriod TimeSpan]
[-MaintenanceSchedule Schedule]
[-MaxItemSize Limit]
[-MountAtStartup <$true | $false>]
[-Name Name]
[-ProhibitPostQuota Limit]
[-QuotaNotificationSchedule Schedule]
[-ReplicationMessageSize Size]
[-ReplicationPeriod Interval]
[-ReplicationSchedule Schedule]
[-RetainDeletedItemsUntilBackup <$true | $false>]
[-UseCustomReferralServerList <$true | $false>]


Usage

Set-PublicFolderDatabase
-Identity "Public DB"
 -IssueWarningQuota 1991680
 -DeletedItemRetention 14
 -MaxItemSize 10240
 -ItemRetentionPeriod "Unlimited"
 -ProhibitPostQuota 2097152
 -QuotaNotificationSchedule "Mon.5:00 AM-Fri.7:00 PM"
 -RetainDeletedItemsUntilBackup $true