Basic xCAT installation

This Blog entry is modified from Basic Install xCAT from xCAT wiki with some minor modification at point 7*, 8* and 9*

1. Pre-install

  • Internal IP of headnode – referred to as (xcat_int_ip)
  • External IP (internet connected) of headnode – referred to as (xcat_ext_ip)
  • External DNS server IP – referred to as (dns_ext_ip)
  • Cluster domain – referred to as (cluster_dom)

2. Network Wiring

  • eth0 is attached into an existing corporate network
  • eth1 is attached to the switch that the compute nodes are attached to

3. Setup Networking
Configure the Ethernet interfaces

vi /etc/sysconfig/network-scripts/ifcfg-eth0


ifdown eth0 && ifup eth0

vi /etc/sysconfig/network-scripts/ifcfg-eth1


ifdown eth1 && ifup eth1

4. Install xCAT
Add the xCAT package repositories

cd /etc/yum.repos.d
yum clean metadata
yum install xCAT

Verify the install

source /etc/profile.d/
tabdump site

If the tabdump command works, xCAT is installed. If it doesn’t work, check to ensure all previous steps completed sucessfully

5. Configure the xCAT site table.

  1. Set the dns to forward requests for the (dns_ext_ip) network
  2. Set the domain to (cluster_dom),
  3. Set the master and nameserver to (dns_ext_ip),
  4. Set eth1 to be the dhcp server interface
tabedit site


6. Setup the xCAT networks table

tabedit networks


There should be an entry for each network the nodes need to access. In this case, DNS is forwarded to the server:

* 7. Setup the xCAT noderes table
(variation from xCAT wiki)
The noderes table defines the resources of the nodes. This includes all of the servers it uses to boot to a usable state and all the types of boot ups it will do.
Note: Primary interface (primarynic) for ipmi machines is the one where the BMC is set to. 

tabedit noderes


*8. Setup the xCAT passwd table
(variation from xCAT wiki)

tabedit passwd


The “omapi” is generated by xCAT. Don’t touch it. But you will need to include the 2nd line “system”

*9. Setup the xCAT chain table
(variation from xCAT wiki)

tabedit chain


*10. Setup the xCAT nodetype table
(variation from xCAT wiki)

tabedit nodetype


11. Setup the xCAT hosts table

tabedit hosts


12. Setup the xCAT mac table

tabedit mac


13. Setup the xCAT nodelist table

tabedit nodelist


14. Setup the xCAT nodehm table

tabedit nodehm


15. Create the hosts file

makehosts all

There should entries in the /etc/hosts that reflect all the nodes

16. Create the DHCP files

makedhcp -n
makedhcp all
service dhcpd restart
chkconfig --level 345 dhcpd on

assuming all the nodes and devices are in the “all” group, that command will work:
Note: dhcpd does NOT need to be restarted after adding a node via makedhcp, but does after running the “-n” option which creates a new file

17. Edit /etc/resolv.conf

vi /etc/resolv.conf
search (xcat_dom)
nameserver (xcat_int_ip)

18. Build the DNS server

makedns all
service named restart
chkconfig --level 345 named on

assuming all the nodes and devices are in the “all” group, this command will work:
Note: named DOES need to be restarted after running a makedns command

19. Routing to the Internet through the Head Node

echo "iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE" >> /etc/rc.local
echo "echo 1 > /proc/sys/net/ipv4/ip_forward" >> /etc/rc.local

* Do remember to configure the gateway for each of the compute node to eth1 (private nic) of the Head Node. Go to client private nic /etc/sysconfig/network-scripts/ifcfg-eth0 and add “GATEWAY=(int_ip_address)”

The xCAT server should now be completely configured.

20. Setup Images

copycds CentOS-5.2-i386-bin-DVD.iso

Note: Do this for the DVD ISO and ”’NOT”’ the cd!

21. Install the node!

rinstall n01

That’s not all. See Using xCAT contributed scripts

3 thoughts on “Basic xCAT installation

  1. Hi,

    Regarding xCAT installation, I see that all installation guides are wit regard to blade servers. I was wondering if we can install xCAT on a intel desktop also.

    Do let me know if it is possible to install xCAT on a home PC (desktop)


  2. Hello there,

    This is very helpful for grasping how things work as well as quickly getting xcat up and running for evaluation. It does seem that newer versions of xcat have changed certain things and this may not be up to date anymore. I was wondering if I could make adjustments to which I see fit and repost it in some fashion? Either on a google blog or other site with link to this as a source?


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