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mr3's avatar
mr3
Level 2
14 years ago

VCS: Group Dependency is violated

Hello,

I've some troubles with an VCS Konfiguration:

 group SG_EC1 (
        SystemList = { vcs-n1 = 0 }
        AutoFailOver = 0
        AutoStartList = { vcs-n1 }
        )

        Phantom EC1_Phantom (
                )

        requires group SG_Platform online global soft

        // resource dependency tree
        //
        //      group SG_EC1
        //      {
        //      Phantom EC1_Phantom
        //      }


group SG_EC2 (
        SystemList = { vcs-n1 = 0 }
        AutoStartList = { vcs-n1 }
        )

        Phantom EC2_Phantom (
                )

        requires group SG_Platform online global soft

        // resource dependency tree
        //
        //      group SG_EC2
        //      {
        //      Phantom EC2_Phantom
        //      }


group SG_Platform (
        SystemList = { vcs-n2 = 0, vcs-n1 = 1 }
        AutoStartList = { vcs-n2, vcs-n1 }
        )

        Phantom Platform_Phantom (
                )



        // resource dependency tree
        //
        //      group SG_Platform
        //      {
        //      Phantom Platform_Phantom
        //      }

As you can see, SG_EC1 and SG_EC2 requires the SG_Platform. I configure online global soft dependency between them. SG_EC1 and SG_Ec2 are not switchable and run on different nodes. Now if I try to switch the SG_Platform, there is following error message:

[root@vcs-n1]~# hagrp -switch SG_Platform -to vcs-n2
VCS WARNING V-16-1-10484 Group dependency is violated if group SG_Platform goes offline on system vcs-n1

[root@vcs-n1]~# hagrp -offline SG_EC1 -any          
VCS NOTICE V-16-1-50733 Attempting to offline group on system vcs-n1
[root@vcs-n1]~# hagrp -switch SG_Platform -to vcs-n2

After I offline one of the SGs (EC1 or EC2, it doesn't matter which one) the hagrp -switch works.

Any ideas?

business continuity
Cluster Server
  • mr3's avatar
    mr3
    14 years ago
    I opened a case and they also thing that this behavious is a bug. Now they check if this issue solved in RP1 or RP2 ... In the meantime I will ether offline and online the SG if I want to switch, or remove this dependencys. Thank you for your posts! Regards Markus

6 Replies

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  • mikebounds's avatar
    mikebounds
    Level 6
    14 years ago

    This should work and I loaded your config into Simulator and it does not - so just to clarify for others in the forum:

    SG_EC1 and SG_EC2 are both online global soft on SG_Platform.  If either of SG_EC1 and SG_EC2 are online then you can switch SG_Platform which you would expect as this is a soft dependency.  But if both SG_EC1 and SG_EC2 are online then you can't switch SG_Platform.  The number of SGs online should not effect the ability of SG_Platform to switch - only the type of dependency should effect switching.

    I consider this to be a bug and so you should log a call with Symantec.

    Mike

  • mr3's avatar
    mr3
    Level 2
    14 years ago

    Thanks Mike,

    I 'll open a support call.

    Regards Markus

  • Marianne's avatar
    Marianne
    Level 6
    14 years ago

    I've had to remove SG dependencies because of this. This problem is seen on different VCS versions on Windows and Unix clusters. I was unable to switch SG's, no matter which dependency type.

    A Symantec Cluster trainer advised me to offline the SG's in the correct order, then manually online them instead of trying to switch.

    I'm quite interested in hearing what the response is from Support.

  • mr3's avatar
    mr3
    Level 2
    14 years ago
    I opened a case and they also thing that this behavious is a bug. Now they check if this issue solved in RP1 or RP2 ... In the meantime I will ether offline and online the SG if I want to switch, or remove this dependencys. Thank you for your posts! Regards Markus
  • mikebounds's avatar
    mikebounds
    Level 6
    14 years ago

    For a work-a-round you can use the RemoteGroup resource which works very well for soft dependencies (doesn't work so well for firm dependencies).  So for example, add the following resoure to SG_EC1 SG (at the bottom of the resource dependency tree):

     RemoteGroup EC1_RG (
  IpAddress = localhost
  GroupName = SG_Platform
  VCSSysName = ANY
  ControlMode = MonitorOnly
  UserName = RG_Op
  Password = encypted_password
  )

    You could use ControlMode = OnOnly if you want if you want VCS to online SG_Platform if it is not online when EC1_RG tries to online (either from a manual online or from a failure).

    Note I woud use a dedicated VCS Operator account for UserName- I would not use "admin" user.  In 5.0 you had to enter user & password for a local cluster and this doesn't appear to have changed in 5.1, but you could try leaving this blank.  If you need any further help using RG resource, let me know.

    Mike

     

  • lee_foster2's avatar
    lee_foster2
    Level 3
    14 years ago

    Hi guys,

    I completely agree with Mike, I have used the remote group agent to get around the service group dependendency with great success on a number of occasions. The control mode options give good control in a cold start of failover scenario where an application depends on a database for example. 

    Regards

    Lee