On Wed, Oct 21, 2009 at 5:30 PM, Michael B. Smith <mich...@owa.smithcons.com> wrote: > To ASB's point.... PST != OST.
Granted, it's been some years, but when I looked into it long ago, PST and an OST were basically the same file format, just used for different purposes. Yes, an OST is a mirror of the "master copy" in Exchange, while PST is not connected to the Exchange IS, but that doesn't matter for purposes of characterizing Outlook's I/O performance. > Today, I consider 5 GB trivial. In terms of disk size, mailbox size, etc., sure. But that doesn't change the fact that a large fragmented PST/OST will drag system performance down severely. At least, that's been my experience with Outlook 2003. Maybe 2007 is different (although from what I've heard, it's not). I don't blame Outlook for this. I would expect poor performance out of *any* large fragmented file that's read in any fashion that isn't completely random. The size doesn't actually have a direct impact; it's just that a large file can get that much more fragmented. If NTFS wasn't so prone to fragmentation, it would be less of an issue, but as you say, that's neither here nor there. (How prone to fragmentation is NTFS? Well, let me put it this way: On that dedicated partition, where there is only *one file*, NTFS still usually manages to turn the OST into three or four fragments. Contiguous but out-of-order. Sometimes I think Microsoft could fall out of bed and miss the floor.) > For Exchange 2010, Microsoft recommends a maximum > mailbox database of 2 TB; but supports mailbox databases up to 64 TB. I'll go tell that sales manager who has 15,000 items in her "Inbox" folder and doesn't see anything wrong with that. ;-) -- Ben ~ Finally, powerful endpoint security that ISN'T a resource hog! ~ ~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/> ~
