[1] purely speed. You never want to be more than 2 index I/O's away from your data. With buffering and caching, blah blah blah - you get 100K items in those 2 index I/O's.
[2] that's fine. Note that these are purely practical limitations for supportability. Your hardware may be fast enough (and you may have enough memory) to support 200K or even 500K items in the mainline folders. But you won't get there by using the standard configuration recommendations - you will have to significantly overprovision. And when using SSD disk - you lose the I/O bottleneck and your new bottleneck will be either memory or proc - it'll require testing. And BrettSh says it's probably (2^32)-1 items but he's never tested it and won't support it (BrettSh is the lead PM for ESE). I have not yet made the investment in SSD, but I did upgrade from 5400 RPM disk to 7200 RPM disk on my main laptop and was shocked at the very noticeable overall speed increase. My next main laptop will have an SSD in it. Ross Smith IV (the guy who wrote and maintains the mailbox calculator spreadsheet) says they absolutely rock. Regards, Michael B. Smith Consultant and Exchange MVP http://TheEssentialExchange.com From: Evan Brastow [mailto:ebras...@automatedemblem.com] Sent: Friday, December 31, 2010 3:54 PM To: MS-Exchange Admin Issues Subject: RE: 2010 Practical mailbox size limitations? Michael, Thanks vey much for your reply. I do appreciate it. When you say mainline folders should have fewer than 100k items, I guess my two follow up questions are: 1) Is that due to speed concerns, or, again, stability? and 2) What about non-mainline folders? For example, a user-created "customer x" folder that, over, 10 years may accumulate hundreds of thousands of emails? I'm going to be upgrading my main customer service reps' computers shortly, and 8GB of RAM and SSD's are not out the question if it means they can better service customers :) Thanks, Evan From: Michael B. Smith [mailto:mich...@smithcons.com] Sent: Thursday, December 30, 2010 3:59 PM To: MS-Exchange Admin Issues Subject: RE: 2010 Practical mailbox size limitations? Stability? No. Speed? Perhaps. The mainline folders should have 100K or fewer items in them (e.g., Inbox, Sent Items, Deleted Items, etc.). Also, without getting into too much detail on the structure of an OST (you can find it on Microsoft's technet if you are really interested), there is a "folder of folders". Basically a folder that contains pointers to every other folder. You don't want that to approach 100K items either. Also, once you get above the 10-15 GB mark, you should be looking at least at 7200 RPM disk; and above 30 GB you might want to look at SSD. Plus assume that Outlook is going to use 2 GB RAM. Now, that's all client side. On the server side, Exchange doesn't care one bit. Validation was done up to 100 GB and the published maximum size is 16 TB (although not a validated size). In fact, you can logically assume that a Public Folder database is a single mailbox. There are people with PF databases that are many hundreds of GB in size. Regards, Michael B. Smith Consultant and Exchange MVP http://TheEssentialExchange.com From: Evan Brastow [mailto:ebras...@automatedemblem.com] Sent: Thursday, December 30, 2010 3:41 PM To: MS-Exchange Admin Issues Subject: 2010 Practical mailbox size limitations? Hi guys, Happy New Year :) Thanks to everyone that's helped throughout this year and so many others! Quick question. In Exchange 2010, is there a recommended size limit for mailboxes? I'm trying to figure out, from a database perspective, why there would be. Whether 10 mailboxes combine to make 10GB, or one mailbox is 10GB, I wouldn't think it would make much difference. We're using Exchange 2010 Enterprise, and using Outlook 2007 clients that are used online with Exchange (not cached.) My reason for asking is that I would like to get mail items out of PST's for one of our mailboxes, and this could cause the mailbox to grow to about 20-40GB in size. I'm trying to figure out of this poses a stability risk. Thoughts? Thanks, Evan --- To manage subscriptions click here: http://lyris.sunbelt-software.com/read/my_forums/ or send an email to listmana...@lyris.sunbeltsoftware.com<mailto:listmana...@lyris.sunbeltsoftware.com> with the body: unsubscribe exchangelist --- To manage subscriptions click here: http://lyris.sunbelt-software.com/read/my_forums/ or send an email to listmana...@lyris.sunbeltsoftware.com<mailto:listmana...@lyris.sunbeltsoftware.com> with the body: unsubscribe exchangelist --- To manage subscriptions click here: http://lyris.sunbelt-software.com/read/my_forums/ or send an email to listmana...@lyris.sunbeltsoftware.com<mailto:listmana...@lyris.sunbeltsoftware.com> with the body: unsubscribe exchangelist --- To manage subscriptions click here: http://lyris.sunbelt-software.com/read/my_forums/ or send an email to listmana...@lyris.sunbeltsoftware.com with the body: unsubscribe exchangelist