ZCS dedicated server vs cluster with dedicated storage

[itsar]

Currently, we are hosted on shared ZCS server. Since our needs are growing, I was planning to move to a dedicated ZCS server for capacity and performance. The hosting company recommends to move to a cluster (I assume, the same platform as it runs now) with dedicated mail store instead. I am trying to understand difference between both setups:

- administration
- resilience
- growth
- performance

They offer to provision a full blown server just for the mail store, which I consider overkill. Why not to run ZCS on it as well?

Thanks

OB

[bdial]

you should read through the multiserver documentation, but an overview kinda goes like this

theres 3 big process in zimbra. the ldap, mta, and mailbox processes

the mailbox process is the web interface, imap, pop3, it's really the biggest and most expensive (cpu/memory) of htem all. however, in a busy environmment, the mta process can cause a lot of load too. thats the antispam/antivirus so it's scanning e-mails/attachments.

so a lot of times people will choose to split off one or more servers to be 'dedicated' to one of these services. or sometimes more. a large deployment may have several ldap servers, several mta servers, and several mailbox servers

as for your points

a) administration: not really that much different. the admin interface can change settings on all servers
b) not sure what you mean really by resillence. it does make it a bit more stable as maybe a really large spam attack won't bring your web interface to a crawl if your mta is running on a different server than your mailbox
c) growth: multiserver is meant for growth
d) performance: same thing

[hescominsoon]

Originally Posted by itsar

Currently, we are hosted on shared ZCS server. Since our needs are growing, I was planning to move to a dedicated ZCS server for capacity and performance. The hosting company recommends to move to a cluster (I assume, the same platform as it runs now) with dedicated mail store instead. I am trying to understand difference between both setups:

- administration
- resilience
- growth
- performance

They offer to provision a full blown server just for the mail store, which I consider overkill. Why not to run ZCS on it as well?

Thanks

OB

How many users?

[itsar]

right now, we have 170 accounts and planning to add 50-70 this years. A&D is enabled for all accounts.

What standard cluster architecture hosting company use for shared account?

OB

[hescominsoon]

Originally Posted by itsar

right now, we have 170 accounts and planning to add 50-70 this years. A&D is enabled for all accounts.

What standard cluster architecture hosting company use for shared account?

OB

I'm not sure that many accounts really requires the expense of a cluster although i can see the rationale. A single server could serve that unless you have tons of traffic for those 150 users. I would investigate how much traffic you have before going any further.

[fcash]

Originally Posted by itsar

right now, we have 170 accounts and planning to add 50-70 this years. A&D is enabled for all accounts.

What standard cluster architecture hosting company use for shared account?

If they are recommending a cluster for you, they are just trying to shake money out of you.

We run 2100 accounts, ~50 Blackberry accounts, ~50 ActiveSync accounts, several dozen Outlook accounts, with Zimbra 5.0 NE in a VM. The VM has 2 virtual CPUs, 8 GB of RAM, and 1 TB of disk (mailstore and backups on RAID10, OS on RAID5). We have a separate SMTP gateway doing spam/virus checking, so this VM has AV/AS disabled. Everything else is installed on here, though.

The host is a dual-core, dual-socket AMD Opteron 2200 (4 cores total @ 2 GHz) with 24 GB of RAM, 12x 500 GB SATA in a single RAID6, and 12x 500 GB SATA in a RAID10 (6x mirrors). VMs get their virtual disk via LVM.

There are now 10 VMs running on this host, including a Windows Server 2003 (BES), a Windows XP (Access DB server), a Windows XP (rdesktop server for Access), a Debian (NX server), and a bunch of web / database / LDAP servers.

Other than some growing pains as we figured out how all the disk caching and KSM worked with Linux-KVM, everything works beautifully. No one complains about it being slow, and we have several hundred open web clients connected all day.

For under 200 accounts, you could run it in VirtualBox on someone's desktop and not even notice. There's no way you need a cluster for that. Anyone suggesting you do is just looking to milk you.