In Exchange Server 2010, there is no more single instance storage (SIS). To help understand why SIS is gone, let's review a brief history of Exchange.
During the development of Exchange 4.0, we had...
Updated May 12, 2020
Version 4.0
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How does this affect the performance of large Query-based Distribution Lists?
Real example here... I have 60,000 Exchange 2003 mailboxes spread across 3 clusters/10 virtual mailbox servers/140 DBs/1 site/1 vLAN. For each database there is a QBDL, and then there is a single QBDL that contains all 130 individual mailbox QBDLs. We use this single list when we need to send emergency and/or weather alerts to all users very quickly (generally 2-4 times per month). Does the need to write the message to all of the mailboxes significantly change the delivery speed of messages when we migrate to Exchange 2010 (in planning at thsi moment)? For reference, the messages are all 2K or less in size and usually come from OWA.
Real example here... I have 60,000 Exchange 2003 mailboxes spread across 3 clusters/10 virtual mailbox servers/140 DBs/1 site/1 vLAN. For each database there is a QBDL, and then there is a single QBDL that contains all 130 individual mailbox QBDLs. We use this single list when we need to send emergency and/or weather alerts to all users very quickly (generally 2-4 times per month). Does the need to write the message to all of the mailboxes significantly change the delivery speed of messages when we migrate to Exchange 2010 (in planning at thsi moment)? For reference, the messages are all 2K or less in size and usually come from OWA.