Information Store is the key components of Exchange Server database management system. It comprises of storage groups that further contains stores: Public Store and Private Store. All this makes up Exchange database that is saved in a file with .edb extension.
While the private store (priv.edb) manages the user mailbox data, the public store (pub.edb) manages the data shared within organization through posts, messages etc.
For various reasons, when there is need to migrate Exchange Server mailbox data to a .pst file arises, the technique of extracting mailboxes and then exporting it to PST can be adopted. However, the mailboxes in .edb file can be extracted only when the database is in consistent state. Any kind of damage or corruption to the database can lead to migration failure! The EDB file can get corrupted at:
- Page Level
- Application Level
- Database Level
In the upcoming part, we will discuss damage to EDB file due to page level corruption and how to escape the problem for smooth mailbox migration to PST file.
Exchange database in EDB file is arranged in 4KB (or multiple of four) pages that holds the MAPI properties of emails and attachments within it. The first two pages of the EDB file comprises of database header while the third physical page is marked as the first logical database page. Depending upon the number of pages that could be created by Exchange Server for a particular edition, the maximum default size of EDB file is defined.
The database gets organized in Balanced Tree (B-Tree) that ascertains quick access to the piece of information from disk and also reduced I/O operations. The pages in the B-tree can store data in it or can point to another page. The search starts with the root page and navigates to the leaf level where the internal pages in between points to the leaf page.
With Exchange Recovery software, repair mailboxes from damaged EDB file to PST file. The tool works on offline and corrupt EDB file and exports the mailboxes to PST, MSG, and EML file. One more reason to invest in this tool is, mailboxes from EDB files can be mounted to active Exchange Server.