The examples below are really high level overviews but....
EV2007 and below SIS was the following
- SIS only performed in the open partition
abcd123yourSite.dvs
- User information
- Archivable Item
- Indexable Item
User Information would be details of the person who archived it.
Archivable Item would be the msg and the attachments compressed
Indexable Item would be the converted archivable item in to either txt and html and this data is used to add to the index
Single Instance Storage in EV2007 and below is fairly limited.
So for instance take the following
-------
Subject: Hello
Attachments: SomeWordDoc.docx (1MB)
From: UserA
To: UserB, UserC, UserD
-------
If UserA, UserB, UserC, UserD all archive the item and are on the same vault store, then the item will be single instanced (as long as the rest of the message headers match)
If all those same users archived it, but UserA and UserB archive it just before a partition is closed, then UserC and UserD archive it in the new partition, you'd have two DVS files
If all users are in seperate vault stores, then you'd have four DVS files resulting from it....
In Enterprise Vault 8 it changed to the following
- SIS can be performed in the entire vault store or across multiple vault stores
- EV will SIS anything above 20k
So for instance in the above scenario, if all vault stores belong to the same vault store group, then that item would be single instanced
The SIS changes to the following though
abcd123.DVS (User Information + mail body)
abcd123.DVSSP (SIS parts, usually attachments)
abc1234.DVSCC (Converted Content, either txt or html)
If an item is < 20k, then the item is stored as a single DVS file
so take the following
-------
Subject: Hello
Attachments: None
From: UserA
To: UserB, UserC, UserD
-------
If all users receive this and its below 20k, then you will have four seperate DVS files.
If all users receive this and its above 20k then you will get the following
4 x *.DVS (1 for each recipient with UI etc)
1 x *.DVSSP (the Attachment referenced by each DVS)
1 x * DVSCC (the converted content of the sis part)
That's a really really basic overview and there are lots of complex examples of how OSIS works in EV8, but SIS has definitely not gone, its more complex and far more effective than previous versions
https://www.linkedin.com/in/alex-allen-turl-07370146