Designing High Availability Solutions with HP Serviceguard and HP Integrity Virtual Machines

cross-subnet cluster by configuring the guest to use DHCP for dynamically obtaining the IP addresses for its virtual

network interfaces, and configuring a bootpd or dhcpd server in each data center to provide the IP addresses for

the guest. To ensure that the VM guest always gets the same IP addresses in a data center, you must configure the

local bootpd or dhcpd server in that data center to assign IP addresses based on the hardware addresses

of the

virtual network interfaces configured for the VM guest.

The following example is for a VM guest, VM1 running in a cross-subnet cluster. Both the VM guest and VM hosts are

running HP-UX. The cluster has nodes running two data centers, and each data center has two networks in unique

subnets. Data center A has subnets 10.10.6.0 and 192.1.6.0, both using a subnet mask of 255.255.255.0. Data

center B has subnets 11.11.7.0 and 192.1.7.0, both using a subnet mask of 255.255.255.0. In data center A,

VM1 should have the IP addresses 10.10.6.22 and 192.1.6.22, and in data center B, VM1 should have the IP

addresses 11.11.7.22 and 192.1.7.22.

1. First you must find the hardware addresses of the virtual network interfaces used by the VM guest:

# hpvmstatus -d -P VM1

[Virtual Machine Devices]

[Storage Interface Details]

disk:avio_stor:0,4,0:lv:/dev/vgHPVM/rlvol1

[Network Interface Details]

network:avio_lan:0,0,0xC25F8A53F65C:vswitch:lanpriv1:portid:1

network:avio_lan:0,1,0x0E4DDBDD652D:vswitch:lanpriv2:portid:1

[Misc Interface Details]

serial:com1::tty:console

Note the hardware addresses for the virtual network interfaces in bold above. You will use these when you

configure the bootpd or dhcpd configuration files.

2. Now on a node connected to the networks in data center A edit the /etc/bootptab and add the following:

VM1: ht=ether: ha=C25F8A53F65C: ip=10.10.6.22: sm=255.255.255.0: \ ds=10.10.6.99

VM1-2: ht=ether: ha=0E4DDBDD652D: ip=192.1.6.22: sm=255.255.255.0

Where:

VM1 and VM1-2—the hostnames that will be associated with the IP addresses for the VM guest when it is running

in data center A

ht=ether—required setting

ha—set to the hardware address of the virtual network interfaces used by the guest

ip—set to the IP address to be assigned to the virtual network interface

ns—set to the subnet mask for the networks in data center A

ds—set to the IP address of the DNS server for data center A (optional)

3. On a node connected to the networks in data center B edit the /etc/bootptab and add the following:

VM1: ht=ether: ha=C25F8A53F65C: ip=11.11.7.22: sm=255.255.255.0: \ ds=11.11.7.99

VM1-2: ht=ether: ha=0E4DDBDD652D: ip=192.1.7.22: sm=255.255.255.0

Also known as MAC addresses.