Random Thoughts by Paul

In Zimbra 5 the RAM settings seem to be very aggressive, aimed at servers with lots of memory. If you are trying to deploy Zimbra on a smaller server you may want/need to tune those down. I don't suggest anything under 2GB of RAM for Zimbra of any size... That said you can view the two main memory settings you'll be tweaking by running the following commands as the zimbra user:

# zmlocalconfig mailboxd_java_heap_memory_percent
# zmlocalconfig mysql_memory_percent

If you experience chown failures where you have no_root_squash (root= in /etc/dfs/dfstab) specified for a nfs client you are probably dealing with an issue of named user/group passing in NFSv4 vs id based passing in NFSv3. Your options are to either specify version 3 or make sure that the users/groups exist on both the cilent and server or make sure they don't exist on the client. That will ensure the id is passed as numeric as there is no name to lookup and pass.

Example:
/etc/group excerpt on client (group monkeys doesn't exist on NFS server)
monkeys::101:

To correct the timezone on a Linux box you need to get the correct /etc/localtime file. Here is how you would set a Centos box to Central time:

cp /usr/share/zoneinfo/US/Central /etc/localtime

I am throwing this one out there as I have seen it bite a few people in the past. You realize your system time is way off and setup ntp and get it running but the system time never updates... You have verified the config and ntp is setup properly. The most likely cause is the fact that ntpd won't correct massive clock skew. If you are off by a great deal you will have to get it in sync manually then ntpd will keep it in sync going forward. This is how you would deal with a clock skew on centos:

yum install ntp
chkconfig ntpd on
ntpdate 0.rhel.pool.ntp.org
/etc/init.d/ntpd start

I moved a great deal of my mail over to Zimbra 5.0 this weekend and the migration went great until I got to one domain where the users had quite a few large attachments. I had neglected to increase the allowable attachment size in Zimbra causing many of the message imports to fail. To up the limit run the following commands as root:

su - zimbra
zmprov mcf zimbraMtaMaxMessageSize 50000000
zmprov mcf zimbraFileUploadMaxSize 50000000

If you are looking for cheap ssl certificates I discovered the other day that Go Daddy has SSL certificates for $19.99 for one year. They also have a pretty sweet deal on multiple domain SSL certificates. Up to 5 domains can be had for $53.99, but be aware that you shouldn't try to be cheap and use that type of cert on unrelated customer uses. It's one cert that is valid for the domains listed in it, so inspecting the certificate will show the sites it is valid for.

I have been using Linux so long that I constantly forget how to do the same operations on a Solaris box, and NFS is definitely different. So here's a note so I don't forget, hope it's useful to someone else.

Linux (redhat/centos):
edit /etc/exports
/etc/init.d/nfs reload

Solaris:
edit /etc/dfs/dfstab
shareall

In rolling out a windows based application recently to a bunch of workstations via login script I thought it would be helpful for the desktop support guys to be able to get any pertinent information about the system at a glance or easily talk a user through getting troubleshooting information for tech support staff. I settled on BGInfo which is a SysInternals (now owned by Microsoft) application that lets you gather and format system information from multiple sources.