Changing the hostname/IP address ================================ Overview -------- This document is intended to describe the steps that must be taken if you need to change your Linux Management Node's hostname and/or IP address after the cluster is installed and configured by xCAT. This documentation will only cover the changes by xCAT and will not try to cover any other changes by any other tools. Backup your xCAT data --------------------- Clean up the database by running ``tabprune`` command: :: tabprune -a auditlog tabprune -a eventlog Now take a snapshot of the Management Node. This will also create a database backup. You can use this data as reference if needed. :: xcatsnap -d Stop xCAT --------- You need to stop the xcat daemon and any other applications that are using the xCAT database on the Management Node and the Service Nodes. To determine your database, run :: lsxcatd -a | grep dbengine To stop xCAT: :: service xcatd stop Stop The Database ----------------- For all databases except SQlite, you should stop the database. For example :: service postgresql stop service mysqld stop Change the Management Hostname ------------------------------- * hostname command :: hostname * Update the hostname configuration files: | Add hostname in ``/etc/hostname`` | Add HOSTNAME attribute in ``/etc/sysconfig/network`` (only for [RHEL]) Update Database Files --------------------- You need to update the new MN hostname or IP address in several database configuration files. SQLite ^^^^^^ Nothing to do. PostgreSQL ^^^^^^^^^^ - Edit ``/etc/xcat/cfgloc`` file... Replace ``Pg:dbname=xcatdb;host=|xcatadm|xcat20`` with ``Pg:dbname=xcatdb;host=|xcatadm|xcat20``. - Edit config database config file ``/var/lib/pgsql/data/pg_hba.conf``... Replace ``host all all /32 md5`` with ``host all all /32 md5`` MySQL ^^^^^ - Edit ``/etc/xcat/cfglooc``... Replace ``mysql:dbname=xcatdb;host=|xcatadmin|xcat20`` with ``mysql:dbname=xcatdb;host=|xcatadmin|xcat20`` Start the database ------------------ :: service postgresql start service mysqld start Start xCAT :: service xcatd start Verify your new database setup :: lsxcatd -a | grep dbengine tabdump site # if output exists Change The Definition In xCAT Database -------------------------------------- Change the site table master attribute ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ :: chdef -t site master= Change all IP address attribute relevant to the MN IP address ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ For example, the old IP address was "10.6.0.1" * Query all the attributes with old address :: lsdef -t node -l | grep "10.6.0.1" ... conserver=10.6.0.1 conserver=10.6.0.1 conserver=10.6.0.1 conserver=10.6.0.1 nfsserver=10.6.0.1 servicenode=10.6.0.1 xcatmaster=10.6.0.1 kcmdline=quiet repo=http://10.6.0.1/install/rhels6/ppc64/ ks=http://10.6.0.1/install/autoinst /slessn ksdevice=d6:92:39:bf:71:05 nfsserver=10.6.0.1 servicenode=10.6.0.1 tftpserver=10.6.0.1 xcatmaster=10.6.0.1 servicenode=10.6.0.1 xcatmaster=10.6.0.1 * Looking at the list above, taking ``conserver`` as an example, query the nodes with ``conserver=10.6.0.1``: :: lsdef -t node -w conserver="10.6.0.1" ... cn1 (node) cn2 (node) cn3 (node) cn4 (node) * Change the conserver address for nodes ``cn1,cn2,cn3,cn4`` :: chdef -t node cn1-cn4 conserver= * Repeat the same process for the other attributes containing the old IP address. Change networks table ^^^^^^^^^^^^^^^^^^^^^ Check your networks table to see if the network definitions are still correct, if not edit accordingly :: lsdef -t network -l chdef -t network Check Result ^^^^^^^^^^^^ You can check whether all the old address has been changed using :: dumpxCATdb -P cd fgrep "10.6.0.1" *.csv If the old address still exists in the ``*.csv`` file, you can edit this file, then use the following command to restore the records :: tabrestore Generate SSL credentials(optional) ---------------------------------- Use the following command to generate new SSL credentials: ``xcatconfig -c``. Then update the following in xCAT: * Update the policy table with new management node name and replace: :: "1.4","old_MN_name",,,,,,"trusted",, with: :: "1.4","new_MN_name",,,,,,"trusted",,`` * Setup up goconserver with new credentials :: makegocons External DNS Server Changed --------------------------- * Update nameserver entries in ``/etc/resolv.conf`` * Update nameserver attribute in ``site`` table :: chdef -t site -o clustersite nameservers="new_ip_address1,new_ip_address2" * Update site forwarders in DB :: chdef -t site -o clustersite forwarders="new_ip_address1,new_ip_address2" * Run command ``makedns -n`` Domain Name Changed ------------------- Change the entries in ``/etc/hosts``. Change the ``/etc/resolv.conf``, forwarders attribute in site table. :: lsdef -t site -o clustersite -i forwarders chdef -t site -o clustersite forwarders Change the domain name in the xCAT database site table. :: chdef -t site -o clustersite domain= From xCAT 2.8, multiple domains is supported in the cluster. Update the networks table definition. :: lsdef -t network -l chdef -t network -o ddnsdomain= Update the Provision Environment -------------------------------- Determine if the Management node is defined in the database, assuming it was done correctly using xcatconfig -m, by running: :: lsdef __mgmtnode If it exists, then use the return name and do the following: - Remove the MN from DNS configuration :: makedns -d - Remove the MN from the DHCP configuration :: makedns -d - Remove the MN from the conserver configuration :: makedns -d - Change the MN name in the xCAT database :: chdef -t node -o -n - Add the new MN to DNS :: makedns -n - Add the MN to dhcp :: makedhcp -a - Add the MN to goconserver :: makegocons Update the genesis packages --------------------------- Run ``mknb `` after changing the ip of MN.