Exchange - event ID 9548 - degrade server performance

Hi --
I read an article this morning regarding event ID 9548 (user_name does not have a master account SID. Please use Active Directory MMC to set an active account as this user's master account) saying that every time this event is logged it is contributing to a possible performance issue. We are running Exchange 2000 and see many entries for this particular event. Can someone please explain?

Many Thanks --
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TheTechGuysNYCConnect With a Mentor Commented:
Event ID 9548 is simply an idiciator to the real problem, but it, in effect, does tell you what the problem is. It seems to me that the problem is as follows:

The account in question (listed on the error message I believe) does not have a master account SID.

Depending on whether or not the account is enabled:
1)Disabled - msExchMasterAccountSID
2)Enabled - objectSID or sidHistory

Event ID 9548 can be easily fixed by granting SELF the right to the mailbox (Associated External Account). (

The performance issue is caused due to the fact that one of the information store threads, per event log, will be forever be trying to resolve the disabled user accounts.
me_mcneelyAuthor Commented:
Thank you for your post. How much of a performance issue would you say that this can cause for lets say 50 disabled accounts?
I set the self permission on all disabled accounts by default as part of my procedures. That hasn't caused by a problem with any of my servers.

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