UNSOLVED

JMikolajek

updated

17 years ago

0

1784

November 16th, 2009 11:00

Host Agent Unreachable

I could use some help with an issue involving a number of hosts not communicating with my cx4-940 clariion san. Here are my symptoms:

  • One storage processor reports "Agent not running" when running "update now" on the host. NaviManager reports the host to be unreachable.
  • The second storage processor reports "Update Operation Failed - client non-data stream err: RWSockERR: in RWSocket:C... NaviManager reports host to be unreachable as well
  • Affected servers were able to connect previously. I also have other hosts that still connect fine.
  • Affected servers running windows server 2008 or windows server 2003 SP2 enterprise
  • NaviAgent service is running on hosts - attempts to recycle service and server does not resolve the issue
  • Only thing in common with these affected hosts is that I recently moved luns from one host to another. I did not cross OS versions - I moved a lun from a 2003 server to another 2003 server and from a 2008 server to a 2008 server. Issue appears to have originated when I stince I performed these moves.

Any help I can get in re-establishing naviagent host connectivity would be greatly appreciated.

Jim Mikolajek

  • kelleg

    6 Operator

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    Posted November 17th, 2009 09:00

    Try opening Connectivity Status and then click on the Serve (right most) column to sort by host name. Find the paths for the host in question and and select one path and then click on the INFO button - that should give you the information about the hostname and IP address - make sure that the IP address listed matches the host's. If it does not then see Knowledgebase article emc66921 on PowerLink.

    glen

  • 778

    0

    Posted November 17th, 2009 12:00

    I verified the info an each path is correct.
  • kelleg

    6 Operator

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    Posted November 17th, 2009 12:00

    Generally there are four reasons that the hosts appear unmanaged:

    1. The IP address that is registered on the array for the host is incorrect - the array can't talk to the host using the IP address

    2. There is a firewall between the host and the array - if so, open port 6389

    3. The Navipshere Host Agent program on the host is not working correctly or not running. Try un-installing, installing Agent again

    4. The switch port configuration on the port that the array's Management Ports are connected to are set to 100/FULL - the array's Management Ports are by default set to auto/auto. Check the switch ports for the correct configuration

    glen

  • PascalJ

    2 Posts

    778

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    Posted November 18th, 2009 05:00

    Hi,

    does the server running the agent is attached to different networks or has more than one NIC installed and configured? If so, you have to create a file called agendID.txt and save it to the agent directory.

    A multihomed host machine has multiple IP addresses connected to networks; it is physically connected to multiple data links that can be on the same or different networks. When you install Navisphere Host Agent on a multihomed host, the host agent, by default, binds to the first NIC in the host. If your host is multihomed, for the host agent to successfully register with the desired CLARiiON storage system, you need to configure the host agent to bind to a specific NIC. You do this by setting up an

    agentID.txt file.


    Example:

    host28.mydomain.com

    192.111.222.3

    The

    agentID.txt file should contain only these two lines, without any formatting. The first line should contain the hostname and the second line should contain the IP address of the HBA/NIC port as described above. Both lines should end with a carriage return. As a result, the cursor will be on a third line but this line should not contain any text.

  • AranH1

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    Posted November 18th, 2009 07:00

    Jim,

    I highly doubt that moving the LUNs between hosts caused this. It is most likely the communication problem with the agents already existed and moving the LUNs helped to reveal it since that action involves communication with the hosts. The Navisphere agent is not very active on the hosts once a host is masked to the array and LUNs have been assigned to the host.

    Have you tried uninstalling and reinstalling the agent. I would also install the latest agent and cli supported by the FLARE code of you array. The Navisphere Agent/CLI uninstall/install is non-disruptive to the host and will not affect the LUN masking or host access to the LUNs. So this can be done during the middle of production hours without any impact to the host.

    Aran

  • 778

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    Posted November 18th, 2009 07:00

    Thank you for your input - unfortunately, it did not have any affect. I have tried recycling the agent service after making this addition as well with no luck. There is a second nic on this server, but it is disconnected and only there in the event the current nic fails. Could this have been caused or have anything to do with moving luns between storage groups/possibly how they were moved?

    Jim

  • 778

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    Posted November 19th, 2009 12:00

    Thank you all for your feedback - I have been able to isolate the cause to be network related. It appears some change to the configuration of the network switch is preventing network connectivity between the SAN and host servers in a specific subnet. Unfortunately, our network backbone is managed by another agency, so modifications/updates/configurations are rarely communicated to me in many instances...
  • AranH1

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    Posted November 19th, 2009 14:00

    Nice. Aren't you looking forward to a converged network when that group will manage your FC traffic as well?
  • dynamox

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    Posted November 19th, 2009 14:00

    i am looking forward to that, then i can blame even more stuff on the networks
  • AranH1

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    Posted November 19th, 2009 15:00

    Oh you will still get the blame. That won't change. But now there won't be anything you can do about it