Zimbra on virtual infrastructures for production use?

[liuk]

Hello all,
I'd like to know your experience of using Zimbra in production systems (not for testing or demo) on Virtual Machines, expecially on VMware Virtual Infrastructure 3 (ESX and ESXi), KVM and Xen.

Please report if possibile dome details about the Virtual infrastructure you are using, the Zimbra configuration (single server or multi server) and how many users in the system.

We are testing Zimbra 5.0.16 OSE in Single Server on ESX 3.5 for about 50 users, with Ubuntu 8.04 64 bit, 2vCPU and 3GB of RAM assigned and reserved to the VM, about 100GB of /opt/zimbra for mailbox data on a local VMFS partition on RAID5, and it seems to behave well (we are in pre-production phase).

We know that Zimbra is heavily based on Java and that Java currently suffers a bit in a virtualized environment compared to native; on the other side it seems that the gap is going to disappear in the near future (see for example [1] )

Awaiting your feedback.
Cheers,
Luca

[1]: VMware: VROOM!: ESX Runs Java Virtual Machines with Near-Native Performance

[phoenix]

You would be better using RAID10 instead of RAID5 for production. If you search the forums you'll find some recommendations for RAID, the following articles have some performance information:

Performance Tuning Guidelines for Large Deployments 6.0 - Zimbra :: Wiki
Performance Tuning Guidelines for Large Deployments - Zimbra :: Wiki

[gracedman]

We are currently testing with VServer. We have chosen this over KVM or Xen (both excellent products) for its virtually native performance and excellent resource usage. Of course, we are assuming a relatively small installation. On the other hand, we have mused that it may make more sense to scale as we outgrow the VM by creating a VServer cluster rather than moving to a dedicated Zimbra server until we grow large enough to justify a dedicated Zimbra cluster.

We have found we had to tweak numerous VServer options for it to work properly but all systems appear to be fully functioning now and performing very well. We do have a very serious issue where shutting down the host is not doing a graceful shutdown of Zimbra and that is creating an absolute mess. Once we resolve that very serious issue, we expect to be VERY happy with our VServer deployment. Hope this helps - John

[fcash]

Our pilot install is currently running in a KVM VM.

The host is:
- 5U rackmount case
- Tyan h2000M motherboard
- 2x dual-core Opteron 2200-series @ 2.6 GHz
- 8 GB DDR2 ECC SDRAM
- 3Ware 9650SE-16ML RAID controller
- 12x 500 GB SATA harddrives in RAID6
- 64-bit Debian Linux 5.0
- KVM 72

The main Zimbra VM has:
- LVM-backed storage
- 2 virtual CPUs
- 3 GB of RAM
- 100 GB system partition (/)
- 500 GB backup partition (/opt/zimbra/backup)
- 1 TB storage partition (/opt/zimbra/store)
- using virtio drivers for NIC and storage
- 64-bit Ubuntu Server 8.10

There are also 2 other Zimbra-related VMs running on this host, one running a custom LDAP server (file-backed VM) that acts as a bridge between our district directory and Zimbra, the other running Windows Server 2003 (LVM-backed VM), Outlook 2003, and the Zimbra Connector for Blackberry.

There are two other VMs also running on this host, both web servers running Drupal on Debian Linux 5.0.

We have under 200 users in Zimbra at the moment. There are no noticeable slowdowns or issues to report.

We're looking at moving to a multi-tiered setup for when we go live with Zimbra, using FreeBSD+ZFS for the storage nodes, and Debian+KVM for the processing nodes, with multiple gigabit ethernet links between them (most likely using iSCSI, but possibly NFS or CIFS).

[PRL]

I recently completed a physical to virtual project for all of our servers using VMware Infrastructure 3.5 with an iSCSI SAN. I used VMware's Cold Boot CD for doing the physical -> virtual migration.

We host email for 150 users, with about 30% of those users using the web client exclusively. The Zimbra virtual disk files (275 GB total) are running on a RAID 10 virtual disk on the SAN. I have assigned it 2 vCPUs and 8 GB of memory. Zimbra is using approx. 4 GB of memory consistently. I could decrease the amount of memory assigned, however we have plenty of available memory on our VMware servers, so I will probably just leave it alone. That's definitely one of the things I love about server virtualization, the ability to increase or decrease the available resources and get the most out of your hardware.