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DMX4 SCSI-3 Reservation - Whether “LU_SCOPE” is implemented??

When Linux hosts are trying to get SCSI3 reservation at DMX4 volumes, reservations are failing. While, we took End-To-End trace during the reservation, we can see that DMX4 is rejecting Persistent_Reserve_Out(Register) command sent by LINUX host. Here is the screenshot from the collected trace

As per standard if scope filed of CDB specifies a scope that is not implemented then command is terminated with check condition and additional sense code set to as “Invalid Field In CDB”

We are seeing the same failure as mentioned above. Scope field value used by host is “LU_SCOPE”. Now as per standard it is the correct value So it is clear that DMX4 is rejecting the register command.

Can any one confirm whether CDB field type “LU_SCOPE” is implemented or not with DMX4. If yes, than why I am seeing the failure. Director Port flags are as below -

Director Port: 0

  WWN Node Name                    : 5006048AD5310397

  WWN Port Name                    : 5006048AD5310397

  Fibre Channel Loop ID            : N/A

  Fibre Adapter Type               : N/A

  Negotiated Speed (Gb/Second)     : N/A

  Director Port Speed (Gb/Second)  : N/A

  SCSI Flags


      Negotiate_Reset(N)           : Disabled

      Soft_Reset(S)                : Disabled

      Environ_Set(E)               : Disabled

      HP3000_Mode(B)               : Disabled

      Common_Serial_Number(C)      : Enabled

      Disable_Q_Reset_on_UA(D)     : Enabled

      Sunapee(SCL)                 : Disabled

      Siemens(S)                   : Disabled

      Sequent(SEQ)                 : Disabled

      Avoid_Reset_Broadcast(ARB)   : Disabled

      Server_On_AS400(A4S)         : Disabled

      SCSI_3(SC3)                  : Enabled

      SPC2_Protocol_Version(SPC2)  : Enabled

      SCSI_Support1(OS2007)        : Enabled


  Fibre Specific Flags


      Volume_Set_Addressing(V)     : Disabled

      Non_Participating(NP)        : Disabled

      Init_Point_to_Point(PP)      : Enabled

      Unique_WWN(UWN)              : Enabled

      VCM_State(VCM)               : Enabled

      OpenVMS(OVMS)                : Disabled

      AS400(AS4)                   : Disabled

      Auto_Negotiate(EAN)          : Enabled

      VNX_Gateway_Direct_Attach    : Disabled


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Re: DMX4 SCSI-3 Reservation - Whether “LU_SCOPE” is implemented??

Is the SCSI3_persistent_reservation flag set on the devices you are using?

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1 Copper

Re: DMX4 SCSI-3 Reservation - Whether “LU_SCOPE” is implemented??

Thanks Jason for quick response.

At FC director ports, I have setup -     SCSI_3(SC3)                  : Enabled

But not at device level....Once I have enabled SCSI3_persistent_reservation flag with each device, SCSI3 Linux cluster reservation worked....

So, Followup question - It seems DMX4 reservation steps are way different than VMAX. With DMX4, is there a way to enable SCSI3_persistent_reservation flag at Storage array itself instead of each device level?



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Re: DMX4 SCSI-3 Reservation - Whether “LU_SCOPE” is implemented??

With VMAX, the device PER flag defaults to YES, compared to NO with DMX. That's the only difference really... an additional step required on DMX if PER is needed.

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