Server requirements for 2000-6000 accounts

[elyse]

I want to migrate over to Zimbra and I am testing it out right now on a small machine to see how it all works. But I need to face the hardware issue.
I have about 1800 accounts and I expect that at some point the number of accounts could get up to 5000-6000. (Note: Approx 1/3 - 1/2 of these would just be POP3 accts.) I have searched the forums here and found some discussion of this but the people who posted their server specs only mentioned 6-20-50 users.

Anybody know what the server requirements would be to handle the load of 2000-6000 accounts?

Thanks in advance!

[andreychek]

Originally Posted by elyse

Anybody know what the server requirements would be to handle the load of 2000-6000 accounts?

Well, while I don't think I'm qualified to answer that question (other than to say you'll probably want a bunch of RAM ;-), those who are qualified are probably going to need to know:

* Mail volume -- it's one thing to know how many users, but it's another to know how much mail they're pulling in

* How often are they checking mail... every 5 minutes? 15? When there's 6000 users, that sort of thing makes a difference :-)

* SSL connections, plain text, or either (SSL connections have a wonderful security benefit, but take more resources)?

I'll offer that you may want to consider a distributed setup, getting that working from the beginning may help things down the road.

With multiple servers, and perhaps a single network storage unit, you could have, say, one server per 2000 users (I'm making the numbers up, you'll need to figure out what ratio is best for you still :-), meaning you'd have 3 live servers when you hit 6000 users. But, you could also keep a fourth standby server to take over if one somehow blew up.

Using network storage, the above setup wouldn't be very complex at all.

Have a good one,
-Eric

[elyse]

Dear Eric, Thanks a lot for the tip. I've rephrased my question here for anyone who has the experience.

I have about 1800 accounts and I expect that at some point the number of accounts could get up to 5000-6000. (Note: Approx 1/3 - 1/2 of these would just be POP3 accts.) I have searched the forums here and found some discussion of this but the people who posted their server specs only mentioned 6-20-50 users.

"* Mail volume -- it's one thing to know how many users, but it's another to know how much mail they're pulling in"

-- Each account will vary a lot but they probably average about 30-50 email per day. (I have some people that get 800 in a day during crazy times but the above is probably a pretty accurate average.)

"* How often are they checking mail... every 5 minutes? 15? When there's 6000 users, that sort of thing makes a difference :-)"

Most will check their mail every few hours actually. But I am sure some will set it to check every 10-20 mins automatically. (These will most likely be the 1/3-1/2 of the accounts which are using a POP3 client.)


"* SSL connections, plain text, or either (SSL connections have a wonderful security benefit, but take more resources)?"

The web connections will most likely all be SSL.

Further, right now we do have a distributed arrangement. However, I was hoping to only need to get two machines -- for load balancing and redundancy. I will have all of my spam filtering done on another server which I already have. So the functions of the Zimbra server(s) will be mainly the web, IMAP and POP mail services (along with the SMTP obviously). I do not expect a lot of calendar action either.

With this data, does anybody know what the server requirements would be to handle the load of 2000-6000 accounts?

Again, thanks to anyone who can provide the data.

best, elyse