Zimbra slow in very small deployment

[alberto]

Hello all,

We have been using Zimbra OS for quite some time now. We are quite happy with it and my deepest congratulations goes to the Zimbra team. However, we have been experiencing a serious slow down on the system as time passes, to the point of making it unusable at times.
Zimbra 5.0.14 GA is installed in a virtual machine running Ubuntu 8.04. This machine has 2.5 Gb allocated of the total 4 of the physical server (which besides that only runs a small web server)
Right now we have only 4 users, at some point in the past we were up to 8. That is what I mean by a very small installation. The only thing not small is mailbox sizes. Most of us have mailboxes that span years of emails and go up to 4 Gb of mails. We do not want to get rid of that info but I'm wondering if that may be the problem.
Anyhow, if we restart the machine the system works perfectly, however, after some hours of use it start to slow down. After several day we start getting errors from the web client saying that the server is taking too long to answer.
I have taking a look at the system and it does not seam to be a problem with memory. Swap is 0.
Most of the time doing top would give me a CPU utilization for the system around 70%, while from restart to a few hour it would run with at least 50% idle.
I thought it may be the amount of span receive and so on but we are getting around 40 messages/hour. It does not seem too many for me but I do not have that much experience.
Could anybody point me to what could be the cause of this behavior?
Any info would be greatly appreciated

[alberto]

Sorry to bump this but can anybody give me a hint as to where to start looking? I can't figure out a reason why this would happen.

[Klug]

Can you post a "top" output (to know if the CPU is "system", "wa", etc)?
What is the RAID setup of the host?
What is the virtualization system used?

[alberto]

I just reboot the machine so I can not get a meaningful top until it starts to slow down.
However, I can tell you that top returns very high use of system when this happens. At first I thought it may be a memory issue and maybe the system is paging as crazy but wa is usually 0 or at values between 0 and 3 %.
The virtual machine is using 2.5 Gb of memory which I thought would be enough for such a small deployment.
It is running in just one disk. Again, I was not specking issues with that since we are talking about 4-5 users but as it's been proven I probably wrong. The disk is a fairly fast 10k rpm.
After several hours of working the id part of top is rarely above 10% and it is most often 0.
I'm using vmware server 2 to run the virtual machine.
I hope this helps. As soon as the machine start to slow down I'll try to get more data.

[Klug]

Originally Posted by alberto

It is running in just one disk.

Unsecure 8-(

Originally Posted by alberto

I'm using vmware server 2 to run the virtual machine.

VMware Server 2 behaves badly (there is a least a thread about it on the forum).

[alberto]

Just one disk maybe relatively insecure depending on your backup strategy and what one is willing to sacrifice. We make backups of the whole machine everyday to a different machine. Those backups have been tested to recover the whole machine in about 10 minutes. Therefore, if we have data corruption we would lose in the worse case scenario about half a day of email. If the disk dies, just set up the virtual machine in another physical machine (which has also been tested) point the outside router to it and you are set. That was the main reason to put zimbra in a vm. I agree that a raid 1 would be better and we may set it up whenever we get sometime.
With regard to vmware, do you think it is possible then that performance degradation comes from using this particular virtualization?

[infernalshade]

Hello!

Our Zimbra is also running in a VM. But not VM Ware. We're using "Sun VirtualBox" and it's running quite good with it! Maybe you can try that? Take a Backup of your machine and install it on a Virtual VirtualBox HardDisk!

[alberto]

Hello internalshade,

I've been wondering if I should do that for some time. Do you know if there is an easy way to convert a vmware image to a virtualbox one?

[infernalshade]

Well i think you'll be glad to hear this:
VirtualBox can read you *.vmdk - VMWare-Image

Just select it in the Manager for Virtual Devices in VirtualBox and assign it to an Virtual Machine (You have to create it before)!

I'm wondering why so much people are still using VMWare...Sun VirtualBox is FREE and comes with the "Guest Additions", which includes a lot of cool Features like:
- Mouse-Integration (Mouse-Capturing isn't needed anymore, just control the VM like a normal Application-Window)
- Resolution-Tool (Just drag and resize the Window of the VM, Guest Additions automatically sets the correct Resolution for the VM!
- 3D Acceleration (In the new Version you can turn it on and use 3D-Effects like the "Vista Aero Theme" or Visual Effects (Whobbling Windows) in Ubuntu)
...



Greetz,
infernalshade

[phoenix]

Originally Posted by infernalshade

Well i think you'll be glad to hear this:
VirtualBox can read you *.vmdk - VMWare-Image

Just select it in the Manager for Virtual Devices in VirtualBox and assign it to an Virtual Machine (You have to create it before)!

Neither of these environments is a supported platform for Zimbra and (IIRC) not even VMware recommend using Server 2 for production use. If you want to virtualise your infrastructure then use a bare metal hypervisor such as VMware ESX(i) or XEN Server.