Anything for sysadmins!


Unknown Start Trace Error (183) when starting Exmon

I recently used the Exchange User Monitor tool to check the connections because the exchange server was running at 100% CPU constantly. When Exmon.exe crashed I weren't able to restart it again as it presented an error. A quick Google query pointed me in the right direction.

An Exchange trace is initiated when the Exmon.exe tool is started. The trace is not closed properly when the tool crashes and it has to be closed manually.

  1. Make sure that Exmon.exe is not running (use CTRL+SHIFT+ESC)
  2. From a CMD run:
    logman query -ets

    This will show you all tracers that are currently running. Notice the Exchange Event Trace that's used by Exmon

  3. Stop the Exchange Event Trace:
    Logman stop "Exchange Event Trace" –ets

If that didn't resolve the issue, check if there's still some space left on the disk or if another user is already running the Exmon tool.


VMWare ESX – Virtual Sockets vs Cores per Socket

We recently updated our VMWare ESX servers to ESX 5.0 which introduced some new features. One of the features is that you can choose between Virtual Sockets and Cores per Socket. I was wondering what the performance difference was between the two. I found an interesting discussion on the SpiceWorks community that confirms my thoughts.

When you select Virtual Socket, the core will be presented to the VM's OS as an actual hardware socket. If the application has been optimized for multiple sockets specifically, it will benefit from this. Same goes for selecting multiple Cores. I can't find any information on what it does to the host's performance though, but it has been mentioned that there's no performance change between the two options. The feature was also introduced for software licensing that is socket or cores based.

Microsoft has already announced that many of the new versions will be on a per core license model.


Office 365 – Exchange Online

No doubt you've heard about Office 365. But have you checked it out already? I have recently checked out all the pros and cons and now it's time to make a small summary of the Exchange Online service.

The people in the company that I work for are quite demanding. I'm currently offering 2GB mailboxes and as expected they are not big enough. To make the entire setup future proof, I'll have to increase the capacity of the Exchange environment drastically - OR - introduce Office 365. Of course I needed to know the limitations of Office 365 to make sure that it meets the expectations of the people that are going to use it. Here are the most important limitations of Exchange Online.

  • Public folders are not available.
  • When using ADFS 2.0 for single sign-on users can't change their password from the Outlook web access.
  • The Office 365 Directory Synchronization toll ignores dynamic distribution groups in on-premise AD.
  • Hierarchical address lists, Global Address List segmentation, custom Global Address List views, and multiple address lists per organisation are not available in Exchange Online
  • Import of .pst files using the New-MailboxImportRequest is not available in Exchange Online. Microsoft introduced the PST Capture Tool to accommodate this need.
  • OWA does not support S/MIME.
  • Administrators can't search the Transport Logs, only Delivery Reports
  • SMTP relay has to be done with a valid licensed Exchange Online mailbox using TLS, which is not widely supported by applications.
  • A deleted Exchange Online mailbox is available for 30 days, after which it is not recoverable. To restore a mailbox within the 30 days, a call to Office 365 support has is required.
  • Granular recovery of deleted email is only available through the dumpster.
  • The personal archive quota is non-configurable.
  • Message limit is set to 25MB and can't be changed.
  • Exchange Online has restrictions that prevent users and applications from sending large volumes of email. Each Exchange Online mailbox can send messages to a maximum of 1,500 recipients per day. An email message can be addressed to a maximum of 500 recipients. These limits apply to emails sent within the internal domain as well as to messages delivered to external contacts. However, a distribution group that is stored in the Global Address List counts as one recipient but in a personal distribution group each recipient is counted separately. Keep in mind that this is not unique recipients per day!

This is just a summary of the most important limitations for my organization. Every organization has its own requirements so it's best to review the documents here:

Here is some pricing information:



If you're considering Exchange Online you might want to look into the Office 365 subscriptions especially when you're also using Microsoft Office. The Microsoft Office suite is quite expensive and it might be interesting to take an Office 365 E3 or E4 subscription as that includes Office Professional Plus.

The whole Office 365 package might be a lot to take in, but when you start calculating the prices it's actually quite interesting. Just take into consideration the pricing of the storage, servers, backup, maintenance and upkeep.

The company I work for is now moving to a hybrid setup. The user mailboxes will be in an on-premise Exchange environment with the personal archives in the cloud using Office 365 Online Archiving.

I hope this helps anyone of you to make a decision!


Windows and Outlook search indexer

Search is quite a vital part of Windows 7 and also of Outlook. People always need to find that special email or file and then search doesn't show the most recent items. One of the solutions might be rebuilding the search index. However these problems have the tendency to keep coming back.

A colleague recently pointed me to an alternative approach. It seems that sometimes Windows is having problems keeping up with all the file changes and all the email that pours in. Just like in Windows Vista, the Windows Search indexer is throttled to make sure that your system stays fast and snappy. If you can't find your files and emails you are slowed down even more. The solution is to disable the indexer backoff. This tells the indexer to just keep going and not to worry about any system activity.

The indexer is especially busy when you install Xobni and it starts indexing all your mail. It will touch all your mail forcing the Windows Indexer to re-index everything. With the indexer backoff enabled it will, which is the default, Outlook performance drags for a long time. When the indexer backoff is disabled the searchindexer.exe process will ramp up the CPU cycles and finish much faster allowing you to find your email sooner!

You can also find this setting in the Group Policy editor under Computer Configuration\Windows Settings\Administrative Templates\Windows Components\Search. The setting is called Disable indexer backoff. You'll want to enable this to turn off the indexer backoff.

As a registry key you can use HKLM\Software\Policies\Microsoft\Windows\Windows Search\DisableBackoff with a value of 1.

Or use this oneliner:
reg add "HKLM\SOFTWARE\Policies\Microsoft\Windows\Windows Search" /v DisableBackoff /t REG_DWORD /d 1 && net stop "Windows Search" && net start "Windows Search"