On Wed, Feb 27, 2008 at 6:18 AM, Jon Harris <[EMAIL PROTECTED]> wrote: > What is the difference between cached and un-cached mode in the client > setting for Exchange?
I see this is already answered, but here's a bit more information: Traditionally, Outlook+Exchange supported "Online" and "Offline" modes. Offline mode was optional. In Online mode, it was simply acting as a network client for the Exchange server, and just about every operation involved talking to the server. In Offline mode, Outlook was disconnected from the server, and using an "Offline Store" (.OST file) for everything. An Outlook client configured to support Offline operation would, when Online, periodically synchronize the OST to the Exchange server. The new-in-2003 "Cached" mode simply means Outlook uses the OST even when the Exchange server is available. It still periodically syncs the OST to the server (every five minutes, I think). If you disable Cached mode, Outlook can and will still use the traditional "Offline" mode on laptops that operate disconnected from the server, so strictly speaking, Cached mode is not *needed* for laptops. But since Offline and Cached modes are basically the same thing, there's not much point in disabling Cached mode on a laptop. There are some Outlook features which only work in Cached mode, the junk mail filter being the big one. (Anyone know why that is?) Cached means the clients talk to the server less often, which means Exchange can handle more clients per server computron. Cached can make a speed difference on the client, too. If the network is slow and/or the client machine is fast, Cached will usually be a speed improvement. If the network is fast and/or the client machine is slow (old), Cached tends to be slower than Online, in my experience. OST (Cached or Offline) can be a performance drag for users with huge (1 GB+) mailboxes. If the users with the huge mailboxes are usually laptop users, you're in trouble either way. Mailbox size restriction policies can of course avoid this issue. If you've got a user (sub)population which hops between client machines frequently, or are using mandatory profiles, disable OST (Cached and/or Offline) for them entirely. The first time Outlook runs for a given user profile on a given machine, it has to copy the entire mailbox from the server to the local OST, so computer hoppers lose big time. Internally, an .OST file and a .PST file are almost identical, or so I'm told. The difference is in how Outlook uses them. An OST is just a local copy of a mailbox on the Exchange server. If an OST file is lost or corrupted, it can be easily rebuilt from the server mailbox (minus any unsync'ed changes). Any PST files are primary copies, and need to be protected like other primary data (backups, etc.). > Any guidance would help a lot. Specific reading for non-Exchange aware > people would be more help. When learning this stuff, I found the following to be very helpful: * "Exchange Server" by Jim McBee (book) * Reading the entire Exchange FAQ * http://www.simpler-webb.com/resources/exchange/faq_db.asp * Note that a lot of the 5.5 and 2000 stuff still applies to 2003 * Lurking on the Sunbelt Exchange list * http://www.slipstick.com/ has lots of tips, tricks, and solutions On Wed, Feb 27, 2008 at 7:22 AM, Jon Harris <[EMAIL PROTECTED]> wrote: > Can OST and PST files live on the same system? > Be open at the same time? Yes and yes. When Outlook is an Exchange client, the Exchange mailbox (server and/or OST) shows up at "Mailbox - Username" in the Folder List. Any PSTs the user opens show up as additional top-level icons in the Folder List. If you haven't already, read the Exchange FAQ entry for "PST = BAD". I'm aware that you're living in the same imperfect world the rest of us are, but you should at least know what the issues are. On Wed, Feb 27, 2008 at 7:58 AM, Jon Harris <[EMAIL PROTECTED]> wrote: > Is there a way to import PST's into OST's? Keep in mind that importing a PST means importing into the mailbox on the Exchange server. That may or may not be a good idea. It will mean you don't have to worry the PST=BAD issues, but it will also mean a big jump in Exchange server storage. It may also mean mailbox size problems. So it depends. In Outlook, Menu -> File -> "Import and Export" will let you import a PST file into the Exchange mailbox. On Wed, Feb 27, 2008 at 8:30 AM, Jon Harris <[EMAIL PROTECTED]> wrote: > ... demanding seamless integration with his email client (he is on OL2k7 > and on a laptop) ... Added Exchange should actually be an improvement, then. Outlook really wants to be an Exchange client. Indeed, that's how it began life, as the Exchange Client program. > ... both demanding the ability to get their email off-campus without using a > web interface. This is easily done with a VPN and/or "RPC-over-HTTP". The native "MAPI wire protocol" Outlook uses to talk to Exchange is based on MS RPC, and isn't firewall friendly. Put a VPN in place, and the clients can talk to the server as if they were on the LAN. With RPC-over-HTTP, Outlook and Exchange implement an RPC proxy mechanism. My understanding is that it isn't really much more than forcing RPC packets over port 80, with a special HTTP verb to make it compatible with the world. It's nothing like the "regular" web with GET/PUT/POST of HTML/XML. -- Ben ~ Upgrade to Next Generation Antispam/Antivirus with Ninja! ~ ~ <http://www.sunbelt-software.com/SunbeltMessagingNinja.cfm> ~
