Prepare the VPS

Before we install Zimbra, we must install the follow packages

root@HN# vzctl exec 101 yum install ant sysstat gmp compat-libstdc++-296 compat-libstdc++-33

The above list should be good enough for Zimbra 6. If installing Zimbra 5, then we also have to have:

root@HN# vzctl exec 101 yum install fetchmail libtool-ltdl

The package "ant" will bring in the latest jdk. The README file in the Zimbra installation package suggests that we use JDK 1.5.0_04. According to this discussion, there were three bugs in JDK 1.6 that prevents Zimbra from using it. I check the status of those bugs and they all have been marked as "fixed".

Next we will test out how Java runs in the VPS.

root@HN# vzctl exec 101 ant

I kept getting error message from ant as below:

Error occurred during initialization of VM
Could not reserve enough space for object heap
*** glibc detected *** /usr/lib/jvm/java/bin/java: double free or corruption (out): 0xb7f4b260 ***

There is a post in the OpenVZ forum that explained how to fix this problem. First check the user_beancounters for problem in resource allocation:

root@HN# vzctl exec cat /proc/user_beancounters

In the output, the last column is "failcnt", which should all be 0. Find the one(s) that is not zero, then adjust in /etc/sysconfig/vz-scripts/101.conf:

root@HN# vi /etc/sysconfig/vz-scripts/101.conf

First, I increased the limit (the value after the colon":") and after validating the file, I restarted the VPS. If it didn't work, then I increased the barrier (the value before the colon ":") and after validating the file again restarted the VPS. To validate the file, run:

root@HN# vzcfgvalidate /etc/sysconfig/vz-scripts/101.conf

Slowly the values in failcnt started decreasing and finally became "0" (zero), I was able to run "ant".

Here are some more posts on UBC:

• UBC failcnt reset
• Resource shortage

Prepare host and MX

We should configure the correct MX and set the fully qualified host name on the host.

If you server is behind NAT, and has a internal IP address, you can do one of the following hacks to satisfy Zimbra installer, which insists on resolving one of the MX to this server:

• If you have a local DNS server, then add a MX record to this server's private IP for the zone of this server's domain. Such record should only answer to local query only. Public view should not get such record.
• If you don't have a local DNS server, then add the public IP address of the MX server as an IP alias of this server.

Install Zimbra

Now install zimbra.

root@vz101# cd zcs-6
root@vz101# ./install.sh --override-platform

If Zimbra won't start, check the "failcnt" in /proc/user_beancounters again. I had to adjuct the UBC values again and again in order for zimbra to start.