The Rocks database holds information that has been discovered about
a host and in particular records network interface information including MAC
addresses and local device modules. The Rocks command line has several tools
to inspect and update entries in the database. Reinstallation of a node will
apply the changes to a node. See the following section on Swapping Frontend
Ethernet Interfaces.
For the following discussion, a frontend named "jeebs" will be used for
illustation. To list the ethernet interfaces do the following:
# rocks list host interface jeebs
SUBNET IFACE MAC IP NETMASK GATEWAY MODULE NAME
private eth0 00:0e:0c:a7:57:d7 10.1.1.1 255.0.0.0 ------------ e1000 jeebs
public eth1 00:19:b9:21:b8:b6 172.19.119.241 255.255.255.0 172.19.119.1 tg3 jeebs.rocksclusters.org |
This describes the two interfaces, eth0 and eth1. Suppose that it is
desired to swap these two interfaces. That is is we would want to associate
the mac address 00:0e:0c:a7:57:d7 with eth1. To do this we must also associate
the correct module. The following will change the information only in the database. This uses the rocks set host interface
group of commands.
# rocks set host interface mac jeebs iface=eth1 mac=00:0e:0c:a7:57:d7
# rocks set host interface module jeebs iface=eth1 module=e1000
# rocks set host interface mac jeebs iface=eth0 mac=00:19:b9:21:b8:b6
# rocks set host interface module jeebs iface=eth0 module=tg3 |
Then the updated database configuration is as follows
# rocks list host interface jeebs
SUBNET IFACE MAC IP NETMASK GATEWAY MODULE NAME
private eth0 00:19:b9:21:b8:b6 10.1.1.1 255.0.0.0 ------------ tg3 jeebs
public eth1 00:0e:0c:a7:57:d7 172.19.119.241 255.255.255.0 172.19.119.1 e1000 jeebs.rocksclusters.org |
 | After any such database change, always run
rocks sync config. This will update service
configuration files (like dhcpd). Reinstalling a node will apply these types of changes to the node. |
The previous section described how to swap two interfaces in the database. For compute nodes it is easiest to simply reinstall nodes for the new
configuration to be applied properly. For frontends, this is not possible
and you should apply the following procedure after you have updated
information in the database. This will recreate the appropriate files.
 | Before performing this procedure, you must be logged into the frontend's
console.
Then, you must shutdown the frontend's network by executing:
|
# sed -i -e '/alias eth/d' -e '/^#/d' /etc/modprobe.conf
# dbreport ifcfg modules jeebs >> /etc/modprobe.conf
# dbreport ifcfg eth0 jeebs > /etc/sysconfig/network-scripts/ifcfg-eth0
# dbreport ifcfg eth1 jeebs > /etc/sysconfig/network-scripts/ifcfg-eth1
# shutdown -r now |
