One of the big problems (In my Humble Opinion) with Exchange is that its one (or a series of) JET based databases. I may be wrong, but I thought JET was something to do with Access. From a long time ago ?
So all the mail for the Exchange server is stored in a shared message store. Okay, you can break them up into a few smaller stores, but essentially if that Exchange server corrupts its data store, you have the choice to restore to your last good backup - if you have one - or spend around one HOUR per gigabyte rebuilding that data store.
So imagine you have 100 users, with say a gigabyte each. 100gb == 100 hours ?
Imagine your Exchange data store corrupts on monday at 9am, and 100 or so hours later - Thursday around noon, say - you can start using your mail again. Ouch, ouch, and double ouch. Remember, everyones out whilst that rebuild is in operation.
Notes/Domino servers tend to store their mail for each user in separate databases. One user screws his mailfile (and this is a very rare thing in my experience), then only one user is affected.
Second big difference is "clustering". On Domino servers, clustering is a application layer transaction "mirror" service that fires network traffic to the other servers, so anytime I make a change to any document on my mail file, all other servers in the cluster that host that mail file get a copy of the update, within a second. Note that each server has its own set of databases, and that by default, all Notes clustering is active-active. Up to six (recommended,but I've seen more) servers, in a cluster, all feeding over reasonably fast network links (10mbit or more recommended.)
So from a DR point of view, you slap two domino servers down - one in the office, and one in the DR site, and with any sort of reasonable network link, you have two standalone machines that keep themselves in sync, and automatically fail over. I've seen people try and do this over ISDN lines - its very very slow, not recommended, etc, but does work.) So just about any reasonably modern wet bit of string will work.
We've had this in the domino world (publically) since v4.5 circa 1996 (we're on v7 now, with v8 next year). Its actually really boring. It just works.
Oh. Domino, remember is multi-platform. Seeing a lot of Linux servers going out on the smaller environments replacing MS windows, and seeing a lot of Solaris, AIX, iSeries and even zSeries in the medium to large environments. Large Pharma, for instance, seems hooked on iSeries - one company I'm aware of servicing over 100,000 accounts from just a dozen (suitably huge) iSeries boxes. And I've seen huge version number mixing going on too - one site I know still has 350+ OS/2 based Notes v4.5 clients (for a particular hard-coded application) but still use more modern v6.5 servers on the back end. Not a biggie, really. Its akin to using Outlook from 1995 against an Exchange 2007 server...
(Of course Domino isnt just mail - its an application infrastructure too. Mail might only represent 30% of the total disk space allocation on a reasonably sized environment).
In the Exchange world, my understanding of "clustering" is that more than one server has to SHARE a physical hard drive subsystem of some description (and already someone previously commented that Exchange doesnt play well with NAS). If that network link "burps" at any point, things get a little scary. So I was privy to a meeting where even with a 100mb/s link, Exchange 2003, and under 200 users, a corporate was scared to "cluster" their Exchange servers as they were convinced that it'd ultimate corrupt itself. As did the Exchange consultant that day - a published Exchange Author. I for one was shocked.
What does this mean ? The biggest mail file I've seen on Domino in the wild - actually in use - was 256gb. Yup. 256gb. About 75gb bigger than the 172gb maximum data store size mentioned above. (Dont ask what they were using it for...)
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I've gotta bite on this.
One of the big problems (In my Humble Opinion) with Exchange is that its one (or a series of) JET based databases. I may be wrong, but I thought JET was something to do with Access. From a long time ago ?
So all the mail for the Exchange server is stored in a shared message store. Okay, you can break them up into a few smaller stores, but essentially if that Exchange server corrupts its data store, you have the choice to restore to your last good backup - if you have one - or spend around one HOUR per gigabyte rebuilding that data store.
So imagine you have 100 users, with say a gigabyte each. 100gb == 100 hours ?
Imagine your Exchange data store corrupts on monday at 9am, and 100 or so hours later - Thursday around noon, say - you can start using your mail again. Ouch, ouch, and double ouch. Remember, everyones out whilst that rebuild is in operation.
Notes/Domino servers tend to store their mail for each user in separate databases. One user screws his mailfile (and this is a very rare thing in my experience), then only one user is affected.
Second big difference is "clustering". On Domino servers, clustering is a application layer transaction "mirror" service that fires network traffic to the other servers, so anytime I make a change to any document on my mail file, all other servers in the cluster that host that mail file get a copy of the update, within a second. Note that each server has its own set of databases, and that by default, all Notes clustering is active-active. Up to six (recommended,but I've seen more) servers, in a cluster, all feeding over reasonably fast network links (10mbit or more recommended.)
So from a DR point of view, you slap two domino servers down - one in the office, and one in the DR site, and with any sort of reasonable network link, you have two standalone machines that keep themselves in sync, and automatically fail over. I've seen people try and do this over ISDN lines - its very very slow, not recommended, etc, but does work.) So just about any reasonably modern wet bit of string will work.
We've had this in the domino world (publically) since v4.5 circa 1996 (we're on v7 now, with v8 next year). Its actually really boring. It just works.
Oh. Domino, remember is multi-platform. Seeing a lot of Linux servers going out on the smaller environments replacing MS windows, and seeing a lot of Solaris, AIX, iSeries and even zSeries in the medium to large environments. Large Pharma, for instance, seems hooked on iSeries - one company I'm aware of servicing over 100,000 accounts from just a dozen (suitably huge) iSeries boxes. And I've seen huge version number mixing going on too - one site I know still has 350+ OS/2 based Notes v4.5 clients (for a particular hard-coded application) but still use more modern v6.5 servers on the back end. Not a biggie, really. Its akin to using Outlook from 1995 against an Exchange 2007 server...
(Of course Domino isnt just mail - its an application infrastructure too. Mail might only represent 30% of the total disk space allocation on a reasonably sized environment).
In the Exchange world, my understanding of "clustering" is that more than one server has to SHARE a physical hard drive subsystem of some description (and already someone previously commented that Exchange doesnt play well with NAS). If that network link "burps" at any point, things get a little scary. So I was privy to a meeting where even with a 100mb/s link, Exchange 2003, and under 200 users, a corporate was scared to "cluster" their Exchange servers as they were convinced that it'd ultimate corrupt itself. As did the Exchange consultant that day - a published Exchange Author. I for one was shocked.
What does this mean ? The biggest mail file I've seen on Domino in the wild - actually in use - was 256gb. Yup. 256gb. About 75gb bigger than the 172gb maximum data store size mentioned above. (Dont ask what they were using it for...)
In my experience, a well ran Domin