I'm at 1.656 with around 500 mailboxes. The database would be, I guess, five or so years old (although we upgraded to Exchange 2007 last summer--not sure if the database-rebuilding that came with that would affect anything).
We have a 250 MB mailbox size limit for nearly every user, so they have to clean up regularly--at least messages with attachments, since those eat up their quota pretty quickly. I think the MS KB article overestimates how often most people clean their mail, though. Their example sites 98% of people deleting an organization-wide message after a week. I know for sure that more than 2% of my users are pack rats, though. I'm really not concerned with SIS as it impacts text-only messages so much as I'm worried about messages with attachments. As I mentioned in the NTSysadmin thread, it's not uncommon for attachments to get sent to our org-wide distribution list. And while I've got a 10 MB attachment limit set, even smaller attachments add up in a hurry when sent to 500 users. Those three 1 MB pictures that a user sends out in a message mean 3 MB x 500 = 1.5 GB of storage required if SIS goes away. I think the only thing mitigating this for us is that we have such a restrictive mailbox size set for most users. John Hornbuckle MIS Department Taylor County School District www.taylor.k12.fl.us -----Original Message----- From: Ben Scott [mailto:mailvor...@gmail.com] Sent: Friday, May 29, 2009 1:31 PM To: MS-Exchange Admin Issues Subject: Single Instance Storage ratio survey Hi all, A thread on nt-sysadmin has got me wondering. Just how much do people actually benefit from SIS (Single Instance Storage) in Exchange? Would people be willing to share their SIS ratio from their Exchange server(s)? Approximations are fine. For multi-server organizations, an average or just picking a server at random would still inform. I'll start: SIS ratio = 5.6 You can discover the SIS ratio by: 1. Open Performance Monitor (PERFMON.EXE) 2. Select "System Monitor" on the left 3. Right-click the graph on the right, and pick "Add Counters" 4. For "Performance Object", select "MSExchangeIS Mailbox" (or similar) 5. Select the "Single Instance Ratio" counter in the list on the left 6. Select the "_ Total" instance in the list on the right 7. Click "Add" 8. If needed, select the resulting counter in the list at the bottom of the graph 9. Look at the "Last" value reported for that counter -- Ben ~ Ninja Email Security with Cloudmark Spam Engine Gets Image Spam ~ ~ http://www.sunbeltsoftware.com/Ninja ~ ~ Ninja Email Security with Cloudmark Spam Engine Gets Image Spam ~ ~ http://www.sunbeltsoftware.com/Ninja ~
