Exchange 2010 – Get available free space in mailbox database

The Exchange mailbox database is always growing and when people say they cleanup you don’t see any changes in the mailbox database size (even not after the x days of the deleted item retention settings). You can see how much free space or white space there is in you mailbox database with a simple powershell command.

Open your Exchange Management Shell and use a combination of Get-MailboxDatabase with the -status option and you find the free space in the AvailableNewMailboxSpace attribute.

Put that all together in one command, you probably want something like :

Get-MailboxDatabase -Status | select Name, DatabaseSize, AvailableNewMailboxSpace

You will get an output like this:

Name                 DatabaseSize                     AvailableNewMailboxSpace
----                 ------------                     ------------------------
Mail01-DB01          92.89 GB (99,735,371,776 bytes)  9.023 GB (9,687,957,504 bytes)
Mail01-DB02          115.5 GB (124,030,353,408 bytes) 4.528 GB (4,861,591,552 bytes)
Mail01-DB03          113.9 GB (122,301,513,728 bytes) 49.69 MB (52,101,120 bytes)

The free space can be reclaimed when you do an offline defragmentation of the database.

Check Also

Exchange 2010 – Get Mailbox Database Mount status

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  1. Hi Martin, I saw this the other week so finished up a post that was sitting in my drafts folder. The AvailableNewMailboxSpace is not 100% accurate, and should not be used. Details in here:

  2. This is a good place to drop this:
    NEVER do offline defrag on a DAG member.

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