Forum Discussion

mokkan's avatar
mokkan
Level 6
11 years ago

Tricky Volume Group cration question

Hello,

 

We would like to have  2 RDM attached to a VM. Is it possible to keep same volume group name ? The reason why I'm asking is that.  SAN team will do the frame base copy time to time from RDM1 to RDM2 so I can't have different volume group name,  metadata (Private region)  will be overwritten when SAN team do the copy.  For the project purpose some times I need to mount RDM1 or RDM2 using VBS.  Is it possible to do?

 

 

 

 

Basics
business continuity
Storage Foundation for Windows
Windows Server (2003-2008)
  • Donald_Cook's avatar
    Donald_Cook
    11 years ago

    Hello All,

    I’m with the Windows support team. It is not possible to present the original & cloned disk group at the same time. When you do a rescan in VEA you will end up with an Unkowndg. This is due to Storage Foundation seeing the same disk group (private region) configuration twice. If the two disk groups were presented to two separate nodes this would be perfectly fine.  The windows version does not use the clone_disk flag etc… as the Unix.

    If you have the flashsnap feature you can achieve the same goal. With flashsnap you can mirror the volumes and split the disk group on the same node. Let me know if you have any questions. I will watch the thread and respond again if need be.

  • Donald_Cook's avatar
    Donald_Cook
    Level 3
    11 years ago

    Hello All,

    I’m with the Windows support team. It is not possible to present the original & cloned disk group at the same time. When you do a rescan in VEA you will end up with an Unkowndg. This is due to Storage Foundation seeing the same disk group (private region) configuration twice. If the two disk groups were presented to two separate nodes this would be perfectly fine.  The windows version does not use the clone_disk flag etc… as the Unix.

    If you have the flashsnap feature you can achieve the same goal. With flashsnap you can mirror the volumes and split the disk group on the same node. Let me know if you have any questions. I will watch the thread and respond again if need be.

  • mokkan's avatar
    mokkan
    Level 6
    11 years ago

    Thank you very much. Atleast now I can see that there is a option in VxVM for hardware copy. I will try to go thorough the doucment and see I can do archieve my goal.

     

    Thanks again for link.

  • Marianne's avatar
    Marianne
    Level 6
    11 years ago

    It seems we need a Storage Foundation for Windows expert here...

    Storage Foundation for Unix knows how to deal with Array snapshot/clone disks, but I cannot find any documentation for Windows:

    How VxVM handles hardware clones or snapshots
    https://sort.symantec.com/public/documents/sfha/6.1/solaris/productguides/html/sf_admin/ch03s12.htm 

    Importing a disk group containing hardware cloned disks
    https://sort.symantec.com/public/documents/sfha/6.1/solaris/productguides/html/sf_admin/ch30s10s09.htm 

     

    I have checked vxdisk command options in SFW admin guides for 6.0 and 6.1. 
    There is no option to "updateudid" as in SF for Unix.

    Hopefully a Symantec expert can help us here? Wally?

  • mokkan's avatar
    mokkan
    Level 6
    11 years ago

    Thank you for the quick reply.  Yes,  it does it in hardware level (Flash Copy).  The  luns are coming from IBM storage and there is a flash copy setup between RDM1 to RDM2, when they do flash copy all the data will be overwritten by RDM1. In this case RDM1 and RDM2 will have the same volume group name. Is it possible to do a setup like this?  I only need to need to use RDM1 or RDM2 at a time.

     

     

     

     

  • Marianne's avatar
    Marianne
    Level 6
    11 years ago

    Are you perhaps referring to Disk Group?

    Each Storage Foundation Dynamic Disk has its own Private Region - whether in same or different Disk Group.

    Please elaborate on this statement?

    SAN team will do the frame base copy time to time from RDM1 to RDM2

    Does this refer to clones made at hardware level?
    Please try to give us as much info as possible.

    Thanks.