100-500 user machine specs

[godovic]

Processor: Core 2 Duo or Quad Core - with 6/12M cache ~ 2.6GHz
RAM: 3-4 GB RAM DDR2
Mail Storage: 2 x 750GB Raid 1 HDD WD enterprise disks
System: 1 x 250GB system
mainboard: GB p35-ds4

I want to run only IMAP for all of my accounts (approx. 100 accounts) and some of them will use webmail

2000 incoming and outgoing e-mails dialy with 30% attachments 5MB+

1. Ubutnu 32 or 64?
2. Zimbra 32 or 64?

please comment and suggest

tnx

[y@w]

Are you looking to expand your user base ever? I'd go with 64 bit just because if you need any extra capacity it will be there. There's really no reason that I know of to limit yourself to the 32-bit version if the machine support 64-bit.

Welcome to the forums, by the way

[rotorboy]

I'm still a n00b but so far on my Q6600 processor system with 6GB RAM and 2x300GB HDD (Software RAID 1 Mirror) and CentOS 5.2-64bit the system has been running very nicely. I'm still at less than half of 100 users, but based on loads so far I don't expect to see any issues at that level. Sounds like you're on track.

[dwmtractor]

Either way (32 or 64) I don't think you're likely to see your system get out of low gear with those specs and only 100 users. It'll be relaxing the whole time.

[Baylink]

Sorry; I only just spotted this thread.

Yes, to the OP: Linux *always* looks like it has no available RAM, after it's been running long enough; don't let it bother you until you see it starting to page out more than a couple MB or so.

[rotorboy]

Thanks for posting that Baylink, With 6GB RAM I see only 180MB "free" at the moment, and my swap is only at 116k. I haven't seen that change notably after adding a dozen users so it just looks like it's taking advantage of the unused RAM.

[godovic]

Originally Posted by y@w

Are you looking to expand your user base ever? I'd go with 64 bit just because if you need any extra capacity it will be there. There's really no reason that I know of to limit yourself to the 32-bit version if the machine support 64-bit.

Welcome to the forums, by the way

Thanks everyone for the welcome and for the very quickest replays ...

Right now we have 60 employees on two different domains hosted on same server, and it will be good for us to double or triple the employees , so it will be my pleasure to configure a new server in that case. I was just wondering if the IMAP require faster storage or anything else?
And probably I should use 64 bit server edition of Ubuntu?

Currently I am using Kerio - Windows Mail server, and here are my statistics:

Server Uptime ~600 days

Messages received by server
Message count 283 326
Message volume 142.6 GB
Total recipient count 353 086

Messages transmitted by server
Message count 389 474
Message volume 213.4 GB
Total recipient count 403 864

Messages delivered to local domains
Message count 326 382
Message volume 155.3 GB
Total recipient count 326 383

Messages sent to remote MX servers
Message count 63 103
Message volume 58.1 GB
Total recipient count 77 480

Antivirus statistics
Attachments checked 747 077
Viruses found 2 697

Spam filter statistics
Messages checked 147 739
Spams detected (tagged) 3 654
Spams detected (rejected) 48 361

SMTP server statistics
Total incoming connections 1 059 111
Lost connections 93 436
Connections rejected by blacklist 652 095
SMTP authentication attempts 120 931
SMTP authentication failures 1 180
Relay attempts rejected by antispam 766
Accepted messages count 272 281
SMTP client statistics
Connection attempts by SMTP client 90 101
DNS lookup failures 5 537
Connections failed 8 937
Connections lost 5 086

POP3 server statistics
Total incoming connections 2 462 774
Authentication failures 62 383
Total count of messages sent to client 347 905

POP3 client statistics
Connection attempts by POP3 client 5 360
Total count of messages downloaded from remote POP3 servers 1 076

IMAP server statistics
Total incoming connections 8 786
Authentication failures 88

WWW (WebMail) server statistics
Total incoming HTTP connections 376 191

[SchlingBlade]

I wish I still had access to the Zimbra system I put in at a wireless ISP about a year ago so I could pull some stats. It was on a Dell 1950 w/dual 3.0Ghz dual-core Xeons (HT disabled), mirrored 300GB SAS drives, 4GB of RAM, ran Ubuntu 6.06 LTS 32-bit (32-bit Zimbra), and served a very busy 4500 customers. No problems with RAM usage, rarely hit swap. It sent and received somewhere around a million messages a day.

I wanted more RAM for the system, and even more drives, but the boss said no. At any rate, it turned out to be MUCH more dependable than the Windows based email system it replaced, which was on better hardware with more RAM.

My home Zimbra system (Open Source) is on a machine with a dual-core AMD Athlon64 X2 3800+ processor, 2GB of RAM, mirrored 160GB SATA drives (software mirroring), Ubuntu 6.06 LTS 64-bit (64-bit Zimbra) and never hits swap. I have about 30 user accounts on that system right now, and will be adding more as time goes on. (This system feels much faster than the Dell 1950 system ever did, even with no users/load on the Dell system)

I agree, 2GB is the minimum you would want for any type of environment. 4GB will do OK, but I've seen that not be enough in a couple cases. 8GB seems to be the sweet spot, but make sure you are on a 64-bit system. Multiple cores/cpus will really help as well. Running Zimbra in a VM for production isn't ideal, use a real server when you deploy for production. Drives don't matter as much, as long as they are reliable and in a good RAID configuration for redundancy.

[mhammett]

Why would Zimbra in a VM be a show stopper?

My thought was to break up Zimbra into a few different systems in independent containers. I don't need that from a capacity perspective at this point, but I like breaking things up into different containers so that I can migrate containers onto bigger hardware without bringing anything down.

[y@w]

Virtualizing Zimbra is not a problem. Our shared Zimbra environment is 100% virtualized. Numerous people have talked about having problems running in Xen, but I'm not aware of issues in general with virtualizing Zimbra.