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NetApp SAN - Failover Test - failed

Hi All

I have couple of servers connected to Node1 and few other servers to Node2.

So when I do a takeover from node2 or node1 and vice versa, how can I achieve HA.

I did a test with few LUNs connected given to Win host from Node 1 and I did a takeover from Node2..

when I logged onto the Win host and noticed that all the NetApp LUNs from Node1 has been disappeared.

And when I did a giveback then I was able to see all the LUNs again.

I Want to know is there any turn around to achieve HA so that when we do takeover from 2 to 1 or 1 to 2 hosts wont loose access to the storage.

thanks in advance.


17 REPLIES 17
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Re: NetApp SAN - Failover Test - failed

I have couple of servers connected to Node1 and few other servers to Node2.

So when I do a takeover from node2 or node1 and vice versa, how can I achieve HA.

You can't in this configuration. To achieve HA host must be connected to both NetApp controllers.

How do you expect it to work? If host is connected to Node1 and Node1 is not available - how host can access data?

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Re: NetApp SAN - Failover Test - failed

thanks for the reply.

i will zone win host to both controllers and check.

qq, so in this case, will the I/O be done though only 1 path or both 2 paths ?

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Re: NetApp SAN - Failover Test - failed

hi Aborzenkov

i tried to zone both Node 1 and 2 

and did a takeover from 2 and same thing happened.. all the LUNs from node 1 disappeared and even after giveback i couldnt see the Node 1 LUNs

i had to reboot the host to get the LUNs appear under disk mgmt.

All,

does any one have their SAN envt in HA, if so can you post the options here.

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Re: NetApp SAN - Failover Test - failed

It is not enough to simply zone both NetApp controllers to host. Hosts (and NetApp) have to be properly configured for multipathing so they can handle path failures.

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Re: NetApp SAN - Failover Test - failed

Hi there,

Install the host utility kit and DSM from NetApp and verify the path from hosts to filers, or use the MPIO.

thank you,

AK G

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Re: NetApp SAN - Failover Test - failed

i have snapdrive installed on the host.

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Re: NetApp SAN - Failover Test - failed

that doesn't show how each lun will reach the both controllers and other properties. Host utility kit is free and dsm requires licensing. If you don't want to use dsm, use the microsoft MPIO feature.

thank you,

AK G

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Re: NetApp SAN - Failover Test - failed

had some hot fixes issues while installing DSM , but at last was able to install DSM on the host.

under DSM, for each device i see that only 3 paths visible instead of 4 paths. ( 2 from Node 1 and 2 from Node 2 ) any idea why DSM is picking up only 3 paths for each device

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Re: NetApp SAN - Failover Test - failed

I would suggest you head back through the entire setup.  Check that all FCP target ports are properly zoned to each initiator.  You've already gotten the MPIO DSM installed and should make sure the FCP Host Utils are also installed.  There are important disk timeout and HBA settings the Host Utils take care of so you don't have to set them manually.  I would then make sure that the igroup on the array has all the initiator WWPNs listed if you have more than one HBA port on the Win host assigned to LUN access.  I would imagine the issue is still somewhere in zoning if you are seeing 3 paths.....maybe one initiator is not included in a zone to the target array?

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Re: NetApp SAN - Failover Test - failed

Current DSM does all necessary settings so host utilities are not required for it (IIRC they actually skip settings if DSM is detected). From DSM release notes:

The Windows Host Utilities are no longer required. The Windows Host Utilities components that enable you to configure Hyper-V systems (mbralign.exe and LinuxGuestConfig.iso) are now included with the DSM. While no longer required, installing the Windows Host Utilities on the same host as the DSM is still supported.

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Re: NetApp SAN - Failover Test - failed

Have you verifed the below?

1.      Check to make sure both nodes on the cluster have identical hosts (wwpn) logged into the “vtic”   

    1. -- igroup show initiators 

          If they are not -- check your SAN Switch Zoning.

 

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Re: NetApp SAN - Failover Test - failed

pls check in the device manager for the number of physical devices that correspond to the number of paths.

(enable hidden devices)

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Re: NetApp SAN - Failover Test - failed

can you please explain whats the diff b/w

(logged in on: vtic, 0d) -->

(logged in on: 0c) -->

(logged in on: vtic) -->

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Re: NetApp SAN - Failover Test - failed

checked the zoning and i can see all WWNs in zoneset

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Re: NetApp SAN - Failover Test - failed

Vtic means that initiator is logged in on partner and works via interconnect.

Check out the KB!
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