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How to check disk space usage in Exchange Server

You can easily check the size of your Exchange databases by using the Database Size Information report. This report not only shows the actual disk space usage, but also the recoverable space in each database, and the size of its associated transaction log.

As you can see, white space and transaction logs can take up a good part of overall disk space consumed, and it makes sense to keep an eye on it. Once again, Promodag Reports can help you!

White space

White space is the area in an Exchange database which is created by the deletion of an item or object, for example a mailbox. It acts like a buffer and it is created along with the mailbox database itself. White space may increase or decrease when you migrate, move, purge or delete mailboxes; the mailbox database will reuse it for any new mailbox item or object. However, the used white space will also take up more disk space and the mailbox database will also allocate more space for it, ultimately increasing the database size.

This PowerShell command gives you the size of your databases and their white space:
Get-MailboxDatabase -status | select Name,DatabaseSize,AvailableNewMailboxSpace

It is recommended to use databases with a lot of white space first and regularly rebalance mailboxes between Exchange databases depending on available disk space.

Transaction log

The Exchange database uses transaction logs to accept, track, and maintain data. All transactions are first written to transaction logs and memory, and then committed to their respective databases. Transaction logs can be used to recover Information Store databases if a failure has corrupted them.

Transaction logs are deleted during backups. It is also possible to set circular logging to avoid consuming all available disk space.

Please consult our homepage for more information about our Exchange and Office 365 reporting products.

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