OST - File Size Limit on NTFS Volume

[Kentucky]

I have a user who is receiving a message generated in Outlook which states
that his mailbox is too large and then the mailbox cleanup dialog opens. On
our corporate network we use cached exchange mode so that people can work
offline with public folder favourites.

I have narrowed down the cause of this message to the OST file. It cannot be
the mailbox size limit on the exchange server as this is set to 85 mb and his
mailbox is of a minimal size of a few KB. I have set his account to not used
chached exchange mode and this has temporarily solved the problem as he is
not receiving the messages any more.

Is there a size limit of 10GB for .ost files or files stored on an NTFS
volume and is it configurable? We have previously experienced a problem where
the OST reaches 2GB and causes the same error messages when stored on a FAT32
volume and converting to NTFS has resolved this.

 

[Roady [MVP]]

No, unicode formatted pst- and ost-file sizes are limited by the size of
your hard disk.

Since ost-files are cached copies of the Exchange mailbox and due to
differences in storage methods the ost-file should be roughly around 125%
the size of your reported Exchange Mailbox size.

--
Robert Sparnaaij [MVP-Outlook]
Coauthor, Configuring Microsoft Outlook 2003


-----
I have a user who is receiving a message generated in Outlook which states
that his mailbox is too large and then the mailbox cleanup dialog opens. On
our corporate network we use cached exchange mode so that people can work
offline with public folder favourites.

I have narrowed down the cause of this message to the OST file. It cannot be
the mailbox size limit on the exchange server as this is set to 85 mb and
his
mailbox is of a minimal size of a few KB. I have set his account to not used
chached exchange mode and this has temporarily solved the problem as he is
not receiving the messages any more.

Is there a size limit of 10GB for .ost files or files stored on an NTFS
volume and is it configurable? We have previously experienced a problem
where
the OST reaches 2GB and causes the same error messages when stored on a
FAT32
volume and converting to NTFS has resolved this.

 

[Sue Mosher [MVP-Outlook]]

Also note that the default maximum size of a Unicode OST file is 20GB, but that can be expanded with a policy setting.

--
Sue Mosher, Outlook MVP
Author of Configuring Microsoft Outlook 2003

and Microsoft Outlook Programming - Jumpstart for
Administrators, Power Users, and Developers

 

[Kentucky]

Yes, but in this case the user has a large volume of public folders added to
his favourites which makes the OST significantly bigger than the mailbox
size. When it reached 10GB Outlook would no longer write to the file and the
hard disk is less than half full. Does anyone know why this is?

 

[Roady [MVP]]

See http://support.microsoft.com/kb/832925

 

[MDV1457]

Hi Sue,
I was hoping to get more information on how to expand the OST to allow a
size greater than 20GB. I'm importing a bunch of mailboxes into one profile
and ran into this snag. I found this kb article but it doesn't seem to make
sense to me because I cannot find the registry entries they refer to in the
article (I checked 3 different machines). Any information you have is
greatly appreciated.

http://support.microsoft.com/kb/832925/en-us

Thanks for the help!

 

[Sue Mosher [MVP-Outlook]]

Standard procedure: If a registry key that you need doesn't exist, add it.

--
Sue Mosher, Outlook MVP
Author of Configuring Microsoft Outlook 2003

and Microsoft Outlook Programming - Jumpstart for
Administrators, Power Users, and Developers