Server spec for approx. 400 users

[ldejongh]

Hi all

I've installed the Open Source edition of Zimbra, and I am impressed. My company is migrating from a hosted Exchange solution, with about 350 users.

Can someone advise me on the hardware spec for 400 users?

My test box is an 8 CPU Xeon box, 4GB of RAM and 80GB of disk space (6 drive bays) - but what would my production server look like, including space to make data dumps and backups?

Thanks again for the great support on the forums so far.

Regards

Lloyd

[mmorse]

4GB of RAM is excellent
(don't know the frequency, but that 8cpu xenon seems fine)
-though I take it your buying new hardware etc

Now for storage:
We need some stats-current quotas & usage, planned quotas, email traffic stats if you have any etc.

With over 100 user's RAID 5 is not recommended.

RAID 10 if you can afford it
else RAID 0+1 or 1+0
RAID 0 has no fault tolerance-so obviously plan accordingly

That being said for very low usage installations (even if a larger # of users) I've seen RAID 5 work fine, but know that it will be one of your biggest performance chokepoints if your looking to increas performance at a later time. Though storage isn't always easy to reconfigure-so I always spring for the best now.

[ldejongh]

Yeah, the test box has excellent specs, however we will be buyin a server just for Zimbra.

I don't have much of the info one would want on current mail uage. The current system is hosted in the UK, it's POP3 and user store mail locally once downloaded. I have no idea right now what the average local storage is.

Would 2GB of RAM, dual CPU and say 1200GB of disk space (4 disks) be sufficient? I expect I can get 6 disks to implement a RAID 10 configuration like you suggest.

We have about 300 users now, and I anticipate growth of up to 400. I expect that the server would be able to handle much more than that if need be, correct?

[mmorse]

ya, spring for RAID10 now (a lot of brands have backplanes that can't be easily switched later...often it requires a full wipe of the disks...)
You can always easily upgrade RAM later as you see fit.
Care to share your server brand & config?

With luck you'll be able to weed people off of POP access-or prevent them from using POP in the first place on this new setup
Now if you wanted to play it safe on storage-slowly convert people, get them using the web client (or IMAP) then disable POP as you go. (You can disable it at the system level, COS level, or individual user level.)

[soxfan]

We also have around 400 users and are using the OS edition of Zimbra. We are doing a gradual migration over to Zimbra, and so far have around 275 active users. We have a Compaq/HP DL380 server, which has dual Xeon 3.4 GHz processors, and 2 GB of RAM. We went with a RAID 10 disk configuration, with 6 146.6 GB 10K SCSI drives. So far we have had no performance issues to speak of. I probably will look to upgrade the RAM to 4 GB or higher, just because more RAM is always better and it's a relatively cheap upgrade.

Hope this helps for comparison purposes.

[ldejongh]

Originally Posted by mmorse

ya, spring for RAID10 now Care to share your server brand & config?

With luck you'll be able to weed people off of POP access-or prevent them from using POP in the first place on this new setup
Now if you wanted to play it safe on storage-slowly convert people, get them using the web client (or IMAP) then disable POP as you go. (You can disable it at the system level, COS level, or individual user level.)

Hi

With the cost we will save not moving to Exchange we can afford RAID 10 I would say. While a new box hasn't been purchased yet, the test box is an old one that's either a Fujitsu/Siemens or a Primergy box. However it has 8 CPUs (1.5GHz Xeon) and space for 6 disks and 4GB RAM.

The point is to replace POP3 with full Exchange-like functionality, so no migration issues there. We want to iron out all the kinks on the OS version, gain experience, then transition to the 60-day trial NE edition once we know what we're doing. Then run NE for the trial period, and purchase a license once everyone is happy.

Our Financial Director is behind it, so it's looking good.

I have one issue though - I'd prefer to run Zimbra on Solaris... Linux (RedHat) is fine, but mission critical is mission critical. If it were available on Solaris you'd have a strong business case.

[ldejongh]

Originally Posted by soxfan

We also have around 400 users and are using the OS edition of Zimbra. We are doing a gradual migration over to Zimbra, and so far have around 275 active users. We have a Compaq/HP DL380 server, which has dual Xeon 3.4 GHz processors, and 2 GB of RAM. We went with a RAID 10 disk configuration, with 6 146.6 GB 10K SCSI drives. So far we have had no performance issues to speak of. I probably will look to upgrade the RAM to 4 GB or higher, just because more RAM is always better and it's a relatively cheap upgrade.

Hope this helps for comparison purposes.

This helps a lot... so your 2GB of RAM is sufficient for your needs? In this environment there are about 160 active users, and maybe 350 total. However I want to spec for growth, and 400 active users was the figure I arrived at.

We will save a great deal of money on network costs by moving the mail server in-house as opposed to the setup in the UK, and even more on Zimbra over Exchange.

Does your disk space suffice for backups and data dumps?

This company is growing, so I want to plan ahead and allow a fair amount of capacity for growth. Also, we have opened an IT consulting agency, and we may be looking to sell solutions around Zimbra and other Open Source/low cost alternatives, and are looking to trial and use packages in-house before deploying to clients.

Regards

Lloyd

[mmorse]

We will save a great deal of money...and even more on Zimbra over Exchange

That's the idea!

dijichi2 is working on a solaris build:
Solaris SPARC straw poll
Solaris10 TEST3 Build
And of course add you comments to:
NEW POLL: What OS port should be next?

Can't hurt to start with 2GB and upgrade as needed-as your trying to save money from the start. Just make a note to your purchasing/financial dept that when everyone's on Zimbra you'll be considering a RAM upgrade after you re-evaluate usage; (you don't have any usage stats afterall-besides 160 users) and webclient/IMAP usage is gonna be different from your current POP setup anyway.

If you contact professional services there is a sizing spreadsheet available.

[soxfan]

so your 2GB of RAM is sufficient for your needs?

So far the 2 GB seems to be sufficient. We are using the Zimbra Web Client, and I would say bottlenecks, if any, are at the client end. Like I said, I'm going to try to bump up the RAM to 4 GB or more, basically "just because".

Does your disk space suffice for backups and data dumps?

We use Tivoli Storage Manager for backups, so no disk space is necessary on the Zimbra server for backups. Since I'm currently using the OSE, which doesn't include any hot backup solution, I would have liked to have setup my disks to do be able to do snap shot backups as described in the Open Source Backup document in the Wiki. However, I didn't read up well enough on it prior to setting up my server and didn't want to go back and do it all over again. I think in general storage requirements vary per setup. We were doing POP3 email prior to the move to Zimbra, so we didn't really have a great idea about how much email our users keep. I spec'd out the server based on giving each user approximately 1 GB of storage for email. We are not currently using quotas, but may have to look into in the future.