Single instance storage is a feature of Exchange that we haven't talked about much since the 1990s. We made some changes to how single-instancing works in Exchange 2007, so I wanted to give everyone ...
Updated Jul 01, 2019
Version 2.0
Blog Post
Hi Nick
Nice article, you got me thinking as you took me back in time to 1995 with your Exchange 4.0 comment. I never understood why anyone really cared about Single Instance Storage. In my experience, from the early days of 4, 5, 5.5sp3 *yay*, 2000 and 2003 SIS was always about message delivery. Most of the systems we would architect had multiple servers in each site, err group. This meant that the real benefit was when a message to 1000 people in a remote site, err group, was delivered it didn't cross the wire 1000 times - just once. SIS was a keen value for Bridgehead (BH) communication, not storage optimization.
Only with the advent of Exchange 2007 64-bit and ultra-large cache and more users and larger databases does this become helpful. SIS is dependent on a lot of users, not just a couple thousand. The more users and data, increase the probability that the same items will exist. *yay* for IOPs management, thanks for making this point.
You mention the introduction of detaching attachments. Administrators can start to see some storage improvements, but is itonly with the pool of users on that server, storage group or store?
You didn't mention that in your post - can you clarify where SIS happens?
Nice article, you got me thinking as you took me back in time to 1995 with your Exchange 4.0 comment. I never understood why anyone really cared about Single Instance Storage. In my experience, from the early days of 4, 5, 5.5sp3 *yay*, 2000 and 2003 SIS was always about message delivery. Most of the systems we would architect had multiple servers in each site, err group. This meant that the real benefit was when a message to 1000 people in a remote site, err group, was delivered it didn't cross the wire 1000 times - just once. SIS was a keen value for Bridgehead (BH) communication, not storage optimization.
Only with the advent of Exchange 2007 64-bit and ultra-large cache and more users and larger databases does this become helpful. SIS is dependent on a lot of users, not just a couple thousand. The more users and data, increase the probability that the same items will exist. *yay* for IOPs management, thanks for making this point.
You mention the introduction of detaching attachments. Administrators can start to see some storage improvements, but is itonly with the pool of users on that server, storage group or store?
You didn't mention that in your post - can you clarify where SIS happens?