High availability virtual ip

[Biran, Yahav (Yahav)]

Many thanks, from some reasons I managed to install it only on 32 bit.

But this is not an issue.

I created the following setup.

the two hosts are running on actual ips 172.16.4.195 and 172.16.4.191
respectively.

The shared ip to be used by the two servers is 172.16.4.242.

this ip is available in the LAN that im running the ucarp.



I also created the two network scripts to support the vip

in /etc/sysconfig/network-scripts/

I simply copy the existing ifcfg-eth0 to ifcfg-eth0:1 as follow:

[root at ilhaisuv01195 network-scripts]# cat ifcfg-eth0

DEVICE=eth0

BOOTPROTO=static

BROADCAST=172.16.7.255

HWADDR=86:EE:0E:6A:F6:92

IPADDR=172.16.4.195

NETMASK=255.255.252.0

NETWORK=172.16.4.0

ONBOOT=yes



[root at ilhaisuv01195 network-scripts]# cat ifcfg-eth0:1

DEVICE=eth0:1

BOOTPROTO=static

BROADCAST=172.16.7.255

HWADDR=86:EE:0E:6A:F6:92

IPADDR=172.16.4.242

NETMASK=255.255.252.0

NETWORK=172.16.4.0

ONBOOT=no



I also tried to executed:

/sbin/ifconfig eth0:2 172.16.4.242 netmask 255.255.255.0 on and

/sbin/ifconfig eth0:2 172.16.4.242 netmask 255.255.255.0 down



The 242 ip was successfully allocated and reallocated.



This two command lines were script as required in the readme to

 /etc/vip-up.sh and /etc/vip-down.sh



[root at ilhaisuv01195 network-scripts]# cat /etc/vip-up.sh

#! /bin/sh

/sbin/ifconfig eth0:2 172.16.4.242 netmask 255.255.255.0 on



[root at ilhaisuv01195 network-scripts]# cat /etc/vip-down.sh

#! /bin/sh

/sbin/ifconfig eth0:2 172.16.4.242 netmask 255.255.255.0 down



Whe I executing the command:

[root at ilhaisuv01195 network-scripts]# /usr/local/sbin/ucarp
--interface=eth0:1 --srcip=172.16.4.195 --addr=172.16.4.242



The following error is generated:

[ERROR] You must supply a valid virtual host id

Can you please advise what seems to be the problem?



yahav







________________________________________

From: Alex Shnitman [mailto:alexta69 at yahoo.com]

Sent: Wednesday, June 17, 2009 12:43 PM

To: Biran, Yahav (Yahav); linux-il at cs.huji.ac.il

Subject: Re: High availability virtual ip



Hi,



Linux-HA is one solution, as has been suggested; another, much easier to set
up, is UCARP -- http://www.ucarp.org/. It handles your virtual IP and the
ARP caching issues associated with it (by means of a GARP packet). I had a
good experience with it.



--Alex



________________________________________

From: "Biran, Yahav (Yahav)" <yahav.biran at gmail.com>

To: linux-il at cs.huji.ac.il

Sent: Tuesday, June 16, 2009 6:58:02 PM

Subject: High availability virtual ip

i have two linux machines, that are running on the same LAN.

i would like to find a way to set HA IP.

i was thinking on creating virtual ip that will ride on the exiting eth.
lets say 10.0.0.1 and 10.0.0.2 and the VIP will be 172.16.4.1

both will run an infinite loop of:while (ping 172.16.4.1) do ...

once that the while is exiting in one of the hosts it will try to acquire
the VIP.

there is additional lock mechanism to implement so the two servers will not
try to acquire the same VIP concurrently.



i would like to know if there is any out of the box sofware that can do this
task?

yahav
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