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Monday, February 26, 2007

Exchange: DST Patching Uncovered


In order to minimize the impact the 2007 Daylight Savings Time changes, Microsoft has released several KB articles to address patching and best practices. Through extensive testing, I hope to shed some light on some best practices, issues uncovered, and the proper procedures. In order to adhere to the Daylight Savings Time changes for 2007, the following must be performed and considered.

1. Install all operatating system DST patches. Install the DST patch for all your Windows servers and XP clients. This includes patching your Exchange server's operating system.

2. Install Exchange DST Patch. Microsoft has released two distinct patches for Exchange 2003. One for Exchange 2003 service pack 1 and one for Exchange 2003 service patch 2. Microsoft has not released Exchange 2000 DST patches. This is only available to customers with extended hotfix support. You can obtain this patch by calling MS. (approx $4,000 usd) The following links provide patches to Exchange 2003.

Exchange Service Pack 2
Exchange Service Pack 1

Note: Both Exchange 2003 patches will update your store version greater than [store. exe 6.5.7233.51] Any store version greater than this will change the behavior of "Send As" functionality. What this means is that, prior to these versions, if you granted Bob full rights to Jim's mailbox, Bob can implicity "Send As" Jim even though Bob does not have "Send As" permission checked. Since Bob has full rights to Jim's mailbox this right is implicit. However, after patching, the implicit "Send As" rights are revoked and you will need to be cognizant as this can break services such as Blackberry. What I recommend is running Microsoft's script that will export all user's that have full mailbox rights on another user but does not have the "Send As" right. The script is pretty straight forward to run and can be obtained in this article.

Note: Be aware of article 932599 Information Store may not start after Exchange DST patching. This is due to duplicate SIDS for well known users or groups (ie. built in) or duplicate attribute values for objects. It is recommended to patch one server first to test since ACL are usually propagated at the Exchange Org\Admin Group level. If one is ok after patching it should be safe to patch others. If you want to be extra safe, you can use this same principal to install a new Exchange server in your org, mount a DB and patch it to see if breaks.

Information Store database does not mount with Event ID 9519 and 9518

3. Run Calendar Update Utility. You must run the calendar update utility after patching your Exchange DST patching. This is separate from your Exchange DST patching in step 2. The utility must be run in order to fix any calendar appointments made during the extended DST time. There are two versions of the calendar update tool, an Outlook Client Tool and an Exchange Server Tool. I have tested both. Here are some considerations.

Exchange Calendar Update Tool

Timezone Update Tool (Outlook)

Exchange Calendar Update Tool (Server Side) - This utility first extracts the timezone information from all user's mailboxes into a text file. Once the text file is exported with this info, it actually uses the client side Timezone Update Tool to update the mailboxes using this file. Here are some considerations when running the Exchange Calendar Update Tool.

- Cannot run on an Exchange server

- You will need to install .Net Framework 2.0, Exchange Calendar Update Tool and the Outlook Timezone Update Tool. The reason you need the client Outlook Timezone Update Tool is because the Exchange Calendar Update Tool calls the executable for the Outlook Update Tool.

- Need to run with a mailbox that has full rights to other's mailboxes. Profile cannot be in cached mode. Also set profile to automatically start in that profile and not select from list.

- If you run utility more than once, any appointments made after you patched your Exchange server with Exchange DST patch will get messed up. This is because the utility will assume that the appointment was made prior to patching. It is recommended to run the utility soon after Exchange DST patching.

- Exchange Calendar Tool processes 6.13 mailboxes a minute and only one thread can be run at a time on one machine. However, you can run on multiple machines.

- If the Exchange DST patch was installed prior to running the Calendar Update Tool (Server or Client) recurring meetings created by OWA will not be updated. To correct, uninstall the DST patch, run the tool, re-install patch.

- Only calendar items in which you were the organizer will get times updated (moved 1hr back)

In large enterprise environments, running the Exchange Calendare Update Tool can take hours\days since it can only process 6.13\mailboxes a minute and only one instance can be running per machine. However, one option you can have is to push the client side Timezone Update Tool to all machines using something like SMS and then having it run the executable with the /q or/quiet switch. This will update the calendar items without user intervention. Works with Outlook open or closed.

Mobile Devices

If you are using mobile devices such as Blackberry consider the following:

1. Remember to update your CDO.dll from your Exchange server to your Blackberry Server
2. Blackberry Handhelds need to be patched. Refer to the following article.


Prepare Outlook calendar items for daylight saving time changes in 2007

How to address daylight saving time by using the Exchange Calendar Update Tool

MsexchangeTeam Step by Step run of Exchange Calendar Update Configuration Tool

James Chong (MVP)
MCSE M+, S+, MCTS, Security+

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xml:lang="en" lang="en"> MS Exchange Tips: February 2007