I run Zimbra 6.0.6 on ubuntu 8.0.4 and everything is fine. I do regular updates of zimbra and my ubuntu. I understand that zimbra provides packages for ubuntu 8.04 cause its an LTS-version that will be support until 2012 or so.

But on my ubuntu-updates I discover that more and more packages are hold back due to dependency-requirements. Usually I then perform a "apt-get dist-upgrade" which does not upgrade to ubuntu 10.04 but does a smarter resolving of dependencies and invites bigger changes.

Now I dont know if I can make this step on my zimbra-server too or if this would affect zimbra?

I want to make this steps, cause regular updates usually means longer having a stable system.

In my actual case I would upgrade/install the following packages:

apt-get dist-upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
The following NEW packages will be installed:
  libdate-manip-perl libdns36 libisc35 linux-image-2.6.24-28-server linux-ubuntu-modules-2.6.24-28-server
The following packages will be upgraded:
  bind9 bind9-host dnsutils imapsync libbind9-30 libisc32 libisccc30 libisccfg30 linux-image-server linux-server
any advice on that?