Tuesday, November 1, 2005

What to do when your .pst file is too big


By Francine Otterson

Phil Iannaco asks:

What can I do with a corrupted PST if scanpst.exe and the 2 gigabyte compression tool doesn't fix it? I am looking, preferably, for something free. If there is a fix worth it's weight, I would be interested in a purchase.

Microsoft has a 2GB size limit on the Outlook personal folders (.pst) and offline folders (.ost) file types [for Outlook versions prior to Outlook 2003]. Once the folder size reaches or goes beyond that size limit the file will not be useable even if you delete items.

I actually recommend not having a personal folder larger than 800MB just for performance and management purposes. If needed, create multiple personal folders and manage each one effectively. For example, instead of having just one filing drawer that is constantly filling up and is perhaps disorganized, consider using two for different purposes, such as one for business and one for home -- that's how multiple personal folders can come in handy.

However, each one of those folders still has to be maintained and that includes making sure that that the 2GB capacity is not even close to being reached. Believe me; you do not want to have to use the truncate tool if it can be avoided. To help prevent this from happening Microsoft has a warning message that appears when files are reaching 1.82GB on Outlook 2002 SP 1 and Outlook 2003.

Just as Phil is experiencing, Personal Folder files can become corrupt or become not useable because they reach the 2GB limit. Slipstick has some tips for fixes, providing the standard Microsoft steps to follow plus some third party add-ins that will not only fix most problems, but help prevent them as your files get bigger. Here's that link:


About Outlook 2003's file sizes

According to Microsoft's knowledge base, article ID 830336:

Microsoft Office Outlook 2003 has both a different format and a larger overall size limit for the personal folders (.pst) file than the .pst files that are in the earlier versions of Microsoft Outlook. In Outlook 2002 and earlier, the .pst files are in the American National Standards Institute (ANSI) format, and the overall size has a limit of 2 gigabytes (GB).
By default, .pst files are in the Unicode format in Outlook 2003. Additionally, the overall size of the .pst files has a limit that is more than the 2-GB limit that is imposed by the ANSI .pst files. By default, the limit for a Unicode .pst file in Outlook 2003 is configured to be 20 GB.

If you don't want to follow the approach of keeping your .pst files to under 2GB, you might consider upgrading to Outlook 2003 and then keeping them under about 18GB.