If you only have 1 router (which is very common) in your subnet then the
router can possibly be a SPOF for IPMP. Here's how you can setup up more
targets for the IPMP to probe so that the router is not a SPOF.
How to Manually Specify Target Systems for Probe-Based Failure Detection
1.
Log in with your user account to the system where you are
configuring probe-based failure detection.
2.
Add a route to a particular host to be used as a target in
probe-based failure detection.
$ route add -host destination-IP gateway-IP -static
Replace the values of destination-IP and gateway-IP with the IPv4
address of the host to be used as a target. For example, you would type
the following to specify the target system 192.168.85.137, which is on
the same subnet as the interfaces in IPMP group testgroup1.
$ route add -host 192.168.85.137 192.168.85.137 -static
3.
Add routes to additional hosts on the network to be used as target
systems.
Taken from:
http://docs.sun.com/app/docs/doc/816-4554/etmkd?l=en&a=view
This should probably be a best practise. However, one can argue that if
the router is down then the cluster is useless anyways.
Sandeep
-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Jim
Senicka
Sent: Monday, October 20, 2008 9:53 AM
To: DeMontier, Frank; Paul Robertson; veritas-ha@mailman.eng.auburn.edu
Subject: Re: [Veritas-ha] IPMultiNICB, mpathd and network outages
I would be more concerned about future failures being handled properly.
If you were able to take out all networks from all nodes at same time,
you have a SPOF. If this was a one time maintenance upgrade to your
network gear and not a normal event, setting VCS to not respond to
network events means that future cable or port issues will not be
handled. If it is a common occurrence for all networks to be lost,
perhaps you need to address the network issues :-)
-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of
DeMontier, Frank
Sent: Monday, October 20, 2008 11:10 AM
To: Paul Robertson; veritas-ha@mailman.eng.auburn.edu
Subject: Re: [Veritas-ha] IPMultiNICB, mpathd and network outages
FaultPropagation=0 should do it.
Buddy DeMontier
State Street Global Advisors
Infrastructure Technical Services
Boston Ma 02111
-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Paul
Robertson
Sent: Monday, October 20, 2008 10:37 AM
To: veritas-ha@mailman.eng.auburn.edu
Subject: [Veritas-ha] IPMultiNICB, mpathd and network outages
We recently experienced a Cisco network issue which prevented all nodes
in that subnet from accessing the default gateway for about a minute.
The Solaris nodes which run probe-based IPMP reported that all
interfaces had failed because they were unable to ping the default
gateway; however, they came back within seconds once the network issue
was resolved. Fine.
Unfortunately, our VCS nodes initiated an offline of the service group
after the IPMultiNICB resources detected the IPMP fault. Since the
service group offline/online takes several minutes, the outage on these
nodes was more painful. Furthermore, since the peer cluster nodes in the
same subnet were also experiencing the same mpathd fault, there would
have been little advantage to failing over the service group to another
node.
We would like to find a way to configure VCS so that the service group
does not offline (and any dependent resources within the service group
are not offlined) in the event of an mpathd (i.e. IPMultiNICB) failure.
In looking through the documentation, it seems that the closest we can
come is to increase the IPMultiNICB ToleranceLimit from "1" to a huge
value:
# hatype -modify IPMultiNICB ToleranceLimit 9999
This should achieve our desired goal, but I can't help thinking that
it's an ugly hack, and that there must be a better way. Any suggestions
are appreciated.
Cheers,
Paul
P.S. A snippet of the main.cf file is listed below:
group multinicbsg (
SystemList = { app04 = 1, app05 = 2 }
Parallel = 1
)
MultiNICB multinicb (
UseMpathd = 1
MpathdCommand = "/usr/lib/inet/in.mpathd -a"
Device = { ce0 = 0, ce4 = 2 }
DefaultRouter = "192.168.9.1"
)
Phantom phantomb (
)
phantomb requires multinicb
group app_grp (
SystemList = { app04 = 0, app05 = 0 }
)
IPMultiNICB app_ip (
BaseResName = multinicb
Address = "192.168.9.34"
NetMask = "255.255.255.0"
Proxy appmnic_proxy (
TargetResName = multinicb
)
(various other resources, including some that depend on app_ip
excluded for brevity)
app_ip requires appmnic_proxy
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