King0770-Notes-Merge Two Independent Machines

Revision as of 04:37, 29 April 2009 by King0770 (talk | contribs) (Section IV - Configure servers)


Summary of steps

  • Prepare ZCS machines
  • Export ldap data from ServerA
  • Import ldap data into ServerB
  • Configure servers

Scenario: You have two ZCS machines, but they are independent of each other. Now a decision has been made to join the machines together.

Why merge two different Zimbra machines?

Possible reasons:

Section I - Prepare ZCS Machines

ZCS Versions

Be sure both machines have the same ZCS version.

LDAP Passwords

LDAP passwords need to be same on both machines.

Run the following command on both machines.

zmlocalconfig -s | grep pass | grep ldap

If the passwords do not match between the two machines, you will need to change the passwords so the passwords match between both machines. After changing the passwords, you will need to restart ZCS services.
(See http://wiki.zimbra.com/index.php?title=Resetting_LDAP_and_MySQL_Passwords#Resetting_the_LDAP_Password)

zmldappasswd -h
Usage: /opt/zimbra/bin/zmldappasswd [-h] [-r] [-p] [-l] newpassword
        -h: display this help message
        -a: change ldap_amavis_password
        -l: change ldap_replication_password
        -n: change ldap_nginx_password
        -p: change ldap_postfix_password
        -r: change ldap_root_passwd
        Only one of a, l, n, p, or r may be specified
        Without options zimbra_ldap_password is changed

Section II - Export ldap data from ServerA

This is actually pretty straight forward. Basically we're going to export the ldap info into a file. Normally we can use the zmslapcat tool to export ldap info, however, we will need to parse out some superfluous info that zmslapcat would include.

Here's a small script to help facilitate this step. Basically, this will export all info the ldap-master will need to import.

#!/bin/bash

if [ `whoami` != "zimbra" ]; then
        echo "You must be the zimbra user to run this script."
exit 0
fi

source /opt/zimbra/bin/zmshutil
zmsetvars

echo "Creating file in /tmp."
ldapsearch -x -h `zmhostname` -D $zimbra_ldap_userdn -w $zimbra_ldap_password -LLL \
"(|(objectClass=zimbraDomain)(objectClass=zimbraAccount)(objectClass=zimbraServer)(objectClass=zimbraCOS))" >> /tmp/`zmhostname`_`date +%F`.ldif


Note: The ldapsearch command is on one line.

Section III - Import ldap data into ServerB

After generating the ldif file on ServerA, transfer it to ServerB. And run ldapadd to import the data into ServerB.

Example: 
ldapadd -x -h `zmhostname` -D uid=zimbra,cn=admins,cn=zimbra -c -w `zmlocalconfig -s -m nokey zimbra_ldap_password` -f /tmp/temp.ldif"

Once the data is imported, restart ZCS services.

zmcontrol stop

zmcontrol start

Section IV - Configure servers

Deciding which machine will be a ldap-master/replica

Up to this point, we were using "ServerA" and "ServerB" in generic terms. We haven't used "ldap-master" and "ldap-replica" terms yet. But now, it is important to be cognizant of which machine will be an ldap-master and which machine will be an ldap-replica. In this article, ServerA exported it's ldap data, and ServerB imported ServerA's ldap data, for our purposes here, ServerA will be an ldap-replica, and ServerB will be an ldap-master once this operation is complete.

ServerA

At this point, we will need to configure ServerA to be an actual ldap-replica.

For this step do the following:

ldap stop

cd /opt/zimbra/openldap-data

/opt/zimbra/sleepycat/bin/db_recover

rm alock *.bdb logs/*

cd /opt/zimbra/openldap-data/accesslog/db

/opt/zimbra/sleepycat/bin/db_recover

rm -rf /opt/zimbra/openldap-data/accesslog

ldap start

Change the server’s local config file to designate it as a replica. Here's an example to go by.

zmlocalconfig –e ldap_master_url="ldap://ServerB:389"
zmlocalconfig –e ldap_url="ldap://ServerA:389 ldap://ServerB:389"
zmlocalconfig –e ldap_is_master=false
zmlocalconfig -e ldap_host=ServerB
/opt/zimbra/libexec/zmldapenablereplica


Or you can script it.


#!/bin/bash

echo "What is the hostname of the ldap master?"
read MAST

zmlocalconfig -e ldap_is_master=false
zmlocalconfig -e ldap_master_url="ldap://$MAST:389"
zmlocalconfig -e ldap_url="ldap://`zmhostname`:389 ldap://$MAST:389"
zmlocalconfig -e ldap_host=$MAST

sleep 1

echo "Running zmldapenablereplica"
/opt/zimbra/libexec/zmldapenablereplica

After making the changes for ldap replication, be sure to restart ZCS services.

zmcontrol stop

zmcontrol start


Server B

If you haven't restarted ZCS services in Section III by now, go ahead and restart ZCS services.

zmcontrol stop

zmcontrol start

Update SSH keys

Don't forget to run "zmupdateauthkeys" on both machines to update their SSH keys

Section V - Test

After both machines have been rebooted, each machine should be able to see each other.

Run the following command from the ldap-replica, both machines should be displayed. If you can see both machines, the merge was successful.

zmprov gas

And run the following to see all the users from the ldap-replica

zmprov gaa

Section VI - Undocumented / Potential Issues

Will document any known issues as I am made aware. More to follow I am sure.

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