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priyanka3rdfeb's avatar
13 years ago
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Does VCS support LVM?

Hi experts,

I have a question. Does VCS support LVM for Apache servicegroup? I have configured  an Apache servicegroup where i have kept the httpd.conf file at local storage of all nodes. I want to move to shared storage now. I am wondering , can i create logical volume (lvcreate ....) , create filesystem (ext2 ) , mount it and copy the httpd.conf there?? will that be recommended solution?? or only vxVM is the recommended solution?

 

Thanks a lot in advance.

  • You can use LVM with VCS, however there is little or no support for 3rd party multipathing depending on what O/S platform (Linux, AIX or HP-ux) and SF version.  It looks like you are using Linux LVM from the commands you mention, so if you are using 5.1, the bundled agents guide says:

     

    You cannot use the DiskReservation agent to reserve disks that have multiple
    paths. The LVMVolumeGroup and the LVMLogicalVolume agents can only be
    used with the DiskReservation agent, Symantec does not support the
    configuration of logical volumes on disks that have multiple paths

     

    For 6.0, you can use Veritas DMP with LVM, but it is not so clear if you can use 3rd party multipathing - see the discussion I started here http://www.symantec.com/connect/forums/using-third-party-multipathing-vcs-lvm-agents for which I got a response which seem to say 3rd party multipathing is not supported, but it was not that clear as the statement in response was "Multipathing is not supported with the LVM agent", but LVM  IS supported with Veritas DMP for Linux and EMC PowerPath and HITACHI HDLM for AIX LVM, but I never got any furher clarification, but perhaps it is just me and maybe it will be clearer to you if 6.0 supports 3rd party multipathing for Linux LVM.

    Mike

5 Replies

  • You can use LVM with VCS, however there is little or no support for 3rd party multipathing depending on what O/S platform (Linux, AIX or HP-ux) and SF version.  It looks like you are using Linux LVM from the commands you mention, so if you are using 5.1, the bundled agents guide says:

     

    You cannot use the DiskReservation agent to reserve disks that have multiple
    paths. The LVMVolumeGroup and the LVMLogicalVolume agents can only be
    used with the DiskReservation agent, Symantec does not support the
    configuration of logical volumes on disks that have multiple paths

     

    For 6.0, you can use Veritas DMP with LVM, but it is not so clear if you can use 3rd party multipathing - see the discussion I started here http://www.symantec.com/connect/forums/using-third-party-multipathing-vcs-lvm-agents for which I got a response which seem to say 3rd party multipathing is not supported, but it was not that clear as the statement in response was "Multipathing is not supported with the LVM agent", but LVM  IS supported with Veritas DMP for Linux and EMC PowerPath and HITACHI HDLM for AIX LVM, but I never got any furher clarification, but perhaps it is just me and maybe it will be clearer to you if 6.0 supports 3rd party multipathing for Linux LVM.

    Mike

  • You should be able to use any supported 'storage agent' as base resources for Apache SG.

    See VCS Bundled Agent Guide. Download from here: https://sort.symantec.com/documents/doc_details/sfha/6.0/Linux/ProductGuides/

    See LVMLogicalVolume agent and LVMVolumeGroup agent in Chapter 2.

    Also see sample dependency diagram for Apache HTTP server agent in chapter 5.

    Use LVM group and volume.

    VxVM is my personal choice that I recommend for each cluster config.
    It is easy to work with, same config across different OS's, etc...

     

    *** Mike is too fast for me! ***

  • Note there is a sample configuration for Apache agent which uses partitions and DiskReservation resources

     

    Mount myapacheMnt( 
      MountPoint="/mnt/apache/"
      BlockDevice="/dev/sdd2"
      FSType = ext3
      FsckOpt = "-y"
      )
    
    DiskReservation myapacheDiskRes(
      Disks = { "/dev/sdd" }
      )

    But this is not "real world" as not many customers uses partitions, but more so, the DiskReservation can not be used with any Disk Multipathing, including Veritas DMP and I have not seen any customer in the last 10 years NOT use Disk Multipathing.

    So you need to be aware that examples in Symantec docuementation, sometimes show a "lab setup"  which is not applicable to "real world" configurations.

    Mike

     

  • Thanks a lot Mike for the helpful reply.

     

    I am not planning to set multi- path now and using VCS 6.0 so i believe , i should be able to use VG , LV in the apache servicegroup.

    Should i go ahead and add LVMVolumeGroup  , LVMLogicalVolume and MountPoint etc resource in my apache servicegroup? or should i create separate servicegroups for VG , LV and mount point?

    Thanks for your help and support.

  • Please see my post below.

    Have a look at figure 5.1 on p. 160 of vcs_bundled_agents_60_lin.pdf (download link in my post)

    Use LVMVolumeGroup and LVMLogicalVolume where the picture says DiskGroup and Volume.