Exchange Single Instance Storage SIS-Microsoft

水电工888

　　I will do a summary about Exchange Single Instance Storage (SIS) at below.
　　Questions / Concerns:
　　===============
　　What does the message and attachment store in database?
　　How many instances will store if we send many emails in organization ?
　　Etc.
　　What is SIS?
　　===============
　　Store just one instance, and creates pointers to link the instance to recipients
　　What SIS can do
　　===============
　　The mainly benefit of SIS is to reduce the storage space.
　　Exchange Server 5.5, Exchange 2000 Server, and Exchange Server 2003 maintain single-instance storage of messages. If a message is sent to one recipient, and if the message is copied to 20 other recipients who reside in the same mailbox store, Exchange maintains only one copy of the message in its database. Exchange then creates pointers that link both the original recipient and the 20 additional recipients to the original message. If the original recipient and the 20 additional recipients are moved to another mailbox store, only one copy of the message is maintained in the new mailbox store.
　　Evolution of SIS for Exchange versions
　　===============
　　Server Version
　　Message
　　Attachment
　　Scope
　　Exchange 2000
　　ü
　　ü
　　Server
　　Exchange 2003
　　ü
　　ü
　　Server
　　Exchange 2007
　　X
　　ü
　　Per database
　　Exchange 2010
　　X
　　X
　　X
　　Exchange 2013
　　X
　　X
　　X
　　Why SIS retired from Exchange Server 2010
　　===============
　　1.The database architectural evolved for the purpose to reduce I/O.
　　2.Disk capacity is no longer a premium. Disk space is cheap and IT shops can take advantage of larger, cheaper disks to reduce their overall cost.
　　3.Exchange developers compressed the databases to reduce storage space.
　　4.………etc.
　　For more detailed information about SIS please see the below articles:
　　Exchange single-instance storage and its effect on stores when moving mailboxes
　　http://support.microsoft.com/kb/175481/en-us
　　Single Instance Storage Ratio is Low
　　http://support.microsoft.com/kb/198673/en-us
　　Moving Mailboxes
　　http://technet.microsoft.com/en-us/library/bb124797(v=exchg.80).aspx
　　http://technet.microsoft.com/en-us/magazine/ee835720.aspx
　　http://blogs.technet.com/b/exchange/archive/2010/02/22/3409361.aspx
　　http://msmvps.com/blogs/jeffloucks/archive/2011/12/16/exchange-2010-did-you-know-single-instance-storage-is-gone.aspx
　　http://blogs.technet.com/b/exchange/archive/2008/02/08/3404852.aspx
　　http://cbfive.com/blog/post/Single-Instance-Store-Behavior-in-Exchange-2007.aspx