Exchange 2007 Leap Year Issue and Mailbox Calulator Update

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Hi All,

Two items came up last week that I wanted to ensure was brought to everyone’s attention:

One:

1.  We have been made aware that some of our Exchange 2007 customers have been experiencing the following issue on Friday Feb 29th:

2. When trying to make certain configuration changes such as new-mailbox or enable-mailbox, certain set of our customers would receive the following error:

3. "The Exchange server address list service failed to respond. This could be because of an address list or email address policy configuration error."

4. Additionally, if you have attempted to set up new Exchange 2007 servers on the 29th, your setup might have failed because of the same error.

5. After investigation of this problem we have learned that this problem would occur only if you have started or restarted the Microsoft Exchange System Attendant service between 12:00AM UTC , Feb 29, 2008 and 12:00AM UTC, Mar 1, 2008. It is important to note that the times involved are UTC , not local server time.

6. If you are impacted by this, all that you have to do is restart the Microsoft Exchange System Attendant service after the midnight UTC, March 1, 2008. Restart of the System Attendant will not disrupt your Information Store service.

7. We are working on a permanent fix for this and will update this when it becomes available. While Feb 29th is over, we want to make sure that this fix is planned for during any future leap year as well.

Two:

The Exchange 2007 Mailbox Server Role Storage Requirements Calculator has been updated. Changes include below:

UPDATE ON 02/29/2008:

Version 13.7.

Bug Fixes

  • Fixed the print margins so that now each worksheet will print out on a single page.
  • Updated several comments across several tables to ensure accuracy with the data being represented.

Enhancements

  • Added the latest version link URL so that you can always check the site to see whether a new version is available.
  • Improved the Log Replication Requirements results section. The new format should make it very clear as to whether the chosen network link is acceptable for log replication. If it is not, a suitable network link is recommended. Additionally, the appropriate Windows Server 2003 TCP/IP settings are listed for both geographically dispersed CCR and SCR.
  • The Storage Requirements result section was updated and enhanced in preparation of a new feature most of you have been asking for...see below, don't want to spoil it...

And last, but not least... New Features

Projected Number of Mailboxes Growth

The first new feature that has been added is the ability for you to specify during the solution's lifecycle the projected growth in terms of number of mailboxes. This way you can now easily model the increase in capacity and performance requirements by dialing the projected growth.

Network Failure Tolerance

When deploying geographically dispersed CCR or SCR across a WAN link there is the possibility that the network link between the two locations will become unavailable. As a result, truncation on the source cannot occur. To ensure you have enough space to survive the network outage an additional parameter needs to be taken into account when sizing space for the Log LUN. Since the calculator already includes a backup failure tolerance parameter, this parameter will only supersede that parameter if it is larger.

As a result, the formula for calculating backup log space requirements is as follows:

NumTLogs x factor

= [If SCRReplayLagTime=0 and SCRTargets<>0 then 50 + NumTLogs, otherwise just NumTLogs] x factor

Where factor is

If performing daily differential backups, factor = MAX(MAX(7, MAX(BackupFailureTolerance,NetFailureTolerance),SCRReplayLagTime+SCRTruncationLagTime),7* MAX(BackupFailureTolerance,NetFailureTolerance))

>>The above formula is for daily differential backups and ensures that we have the largest window in terms of capacity to survive multiple truncation failures (since log truncation only occurs once a week), a network outage, or to have enough capacity to handle the SCR window.

· If Restore LUN = yes, factor = MAX(SCRReplayLagTime+SCRTruncationLagTime, MAX(BackupFailureTolerance,NetFailureTolerance))

>>The above formula is for daily incremental backups or daily full backups (with Restore LUN) and ensures we have enough capacity to survive multiple truncation failures, a network outage, or to have enough capacity to handle the SCR window. Since a Restore LUN exists, we don't need to be concerned with restore capacity (i.e. 7 days worth worst case with daily incremental backups) on the Log LUN.

o If Restore LUN = no and performing daily incremental backups, factor = MAX(MAX(BackupFailureTolerance,NetFailureTolerance),SCRReplayLagTime+SCRTruncationLagTime,7)

>>The above formula is for daily incremental backups (without a Restore LUN) and ensures that we have enough capacity to handle restoration of all logs (7 days) or survive multiple truncation failures, a network outage, or have enough capacity to handle the SCR window.

o If Restore LUN = no and performing daily full backups, factor = MAX(SCRReplayLagTime+SCRTruncationLagTime,MAX(BackupFailureTolerance,NetFailureTolerance))

>>The above formula is for daily full backups (without a Restore LUN) and ensures that we have enough capacity to survive multiple truncation failures, a network outage, or have enough capacity to handle the SCR window.

Multiple Mailbox Server Support

This has been the most requested feature for the calculator. So I've delivered it finally! You can now enter into the calculator how many mailbox servers you want in your environment. In turn, the calculator will recommend per server requirements, as well as, output requirements for all servers entered. Please note that there are a few restrictions/caveats:

  1. All mailbox servers are configured the same (i.e. you cannot select CCR for some and not the rest).
  2. The calculator will evenly distribute the number of mailboxes entered in Step 2 across all mailbox servers. So if you enter into the calculator 10000 mailboxes, and choose to have 2 mailbox servers, 5000 mailboxes will be placed on server 1 and 5000 mailboxes will be placed on server

End of the update.

Both of these updates were available through the Exchange blog which you can add into your RSS feeds https://msexchangeteam.com/rss.aspx . To read the updated calculator blog post and get the calculator, go HERE.

Nick.