Structure of the MailStore Database
A MailStore database consists of the following:
The Master Database
Every MailStore Server installation has exactly one master database where general information such as users, email folders and settings are stored. Compared with file groups (see below), the master database has a very small storage space requirement.
The master database is included in the setup of MailStore Server and is installed and set up automatically. Through the MailStore Server Configuration, the storage location of the master database can be determined and changed, if desired. The master database can be stored on a local drive or on a network location specified by an UNC path as well. For further information please refer to the article Using Network Attached Storage (NAS).
The master database is integrated in MailStore Server (embedded database) and can be run concurrently with other database systems.
The actual data - the archived emails - is stored in file groups. During the initial installation of MailStore Server, a first file group is created automatically. To distribute the archive among several storage locations, any number of additional file groups can be added at any time. In addition to allowing for flexible management of the storage space, the creation of new file groups has a positive influence on the performance of the archive.
A file group consists of:
- Database - The database stores a list of the individual emails, including header information, as well as a list of indexes.
- Content - The actual email content is stored in .DAT files. Generally, these files have a manageable size of approximately 8 MB each, but individual files can vary considerably in size.
- Index - One index per user is created, which makes extremely fast searches possible within MailStore. In addition, indexes are used for navigation within the tree structure.
Managing Storage Locations
In Storage Locations Management, the location of the master database can be viewed and the file groups of the archive can be managed. The file groups contain the actual data, the archived emails; by creating new file groups the complete archive can be distributed among different storage locations (e.g. different hard drives); existing file groups can always be moved at a later time.
Accessing Storage Locations Management
Log on to MailStore Client as administrator. Click on Administrative Tools > Storage and then on Storage Locations.
Changing the Storage Location of the Master Database
Here, the storage location of the master database can only be viewed. By clicking on Change, only a summary of the steps (as described below) required to change the location is displayed:
Start the MailStore Server Base Configuration which is located in the MailStore Server program folder in the Windows Start menu (on the MailStore Server PC). Select the storage location of an existing master database (e.g. to restore a backup). If an empty directory is chosen, a new master database will be created.
Store Newly Archived Email In...
Below File groups, there is the option to Store Newly Archived Emails In. Select the file group into which new emails are to be archived. Only file groups that are not write-protected can be chosen; their status can be changed at runtime.
Creating a New File Group
To create a new file group, click on New in the menu bar at the bottom of the window. Select an empty directory and click on OK.
Write-Protecting a File Group
Select a file group from the list and, in the menu bar on the bottom of the window, click on Write Protect.
The emails stored in a write-protected file group remain fully available to MailStore users and can be located through the folder structure or by running a search. However, neither can new emails be archived into this file group nor can existing ones be deleted from it. Please keep in mind that the file system still requires write access to the file group.
After a file group has been write-protected, it is marked in the list with a lock symbol next to it.
To remove the write-protection, select the appropriate file group and click on Write Protect again.
Attaching and Detaching File Groups
Existing file groups can be detached from the archive: Simply select a file group from the list and click on Detach in the menu bar on the bottom of the window. Once detached, the file group and the emails contained therein are no longer available in the archive. This feature can be used for taking old parts of the archive out of storage, for example.
A detached file group can be reattached to the archive at any time: by clicking Attach, the file group becomes fully available again. Please note: Only file groups which originated from the same archive can be attached; file groups from external archives cannot be integrated.
Moving File Groups
To move a file group, please proceed as follows:
- Detach the file group to be moved: Select the appropriate group from the list and click on Detach.
- Use Windows Explorer to move the file group to a different directory on any local(!) network.
- Reattach the file group: Click on Attach and select the new storage location of the file group. Click on OK to confirm.
Maintenance of the Storage Locations
The following features are available through Maintenance in the menu bar on the bottom of the window:
- File Group - Free Unused Disk Space
- File Group - Check Data Integrity
- File Group - Cleanup (FB Sweep)
Simple cleanup of a file group database.
- File Group - Rebuild (FB Backup+Restore)
Complete rebuilding of a file group database (e.g. if structural problems occur).
- File Group - Recalculate Statistics of all File Groups
Creating File Groups Automatically
MailStore Server can be configured to create and activate new file groups in regular intervals, e.g. monthly or quarterly. Please proceed as follows:
- Start MailStore Client and log on as MailStore administrator (admin).
- Click on Management Shell.
- Enter the following:
schedule filegroup-create-auto --basedir="D:\FileGroups"
Instead of "D:\FileGroups" enter the directory in which new file groups are to be created. File groups, including subdirectories, that are created automatically by MailStore are named using the format Year-Month, for example 2009-04.
- A dialog window appears.
- Click on Other Trigger.
- Click on OK.
- In the window Schedule click on New.
- Under Schedule Task select Monthly.
- If new file groups are to be created quarterly, click on Schedule Task Monthly and select only January, April, July and October, for example.
- Click on OK and follow the directions on the screen.
Performance: For every 500,000 emails, a new file group should be created. This ensures a consistently high access speed when searching emails.
One-time backup: Older file groups can be write-protected (see above). These file groups remain available to users (with the exception of moving or deleting emails) but do no longer have to be backed up constantly. Write-protected file groups can be kept on cost-efficient storage media without any risks.