HP OpenVMS Systems

Control of MSCP Disk Services?

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The Question is:

 
A cluster of two AlphaServers with a shared SCSI bus connected to a HSZ70
with 24 disks. PORT allocation classes in use.
Both systems see their local disks and the shared disks. MSCP_LOAD is 0 on
both systems. If I set MSCP_LOAD to 1 and MSCP_SERVE_ALL to 2 would this
serve only the local disks and not the shared disks?
 

The Answer is :

 
  Unfortunately, no.
 
  All SCSI devices are considered "local" by the MSCP server.  In addition,
  the MSCP server explicitly determines that any device configured with a
  port allocation class is also "local".  There is no easy way to prevent
  devices on a shared SCSI bus from being exported by the MSCP server.
  (For the purposes of MSCP disk services, only storage devices on the CI
  such as the HSC, HSJ, and storage ISEs on a DSSI, are considered to be
  "remote" devices by the MSCP server.)
 
  Assuming that you wish to prevent devices on the shared SCSI bus being
  exported to the other hosts on that SCSI bus, there is only one way to
  accomplish this.  Set MSCP_SERVE_ALL to zero, and then explictly issue
  a SET DEVICE/SERVED for each device you *do* want exported to clients.
  Admitedly, this is awkward, but it is the only solution right now.
 
  If you are willing to upgrade to OpenVMS Alpha V7.2-1 or later, you can
  use the SCSI multi-path feature, which will sort out the multiple paths
  and make them all available to you (and it allows you to switch between
  them manually).  This is not yet supported for MSCP devices, but the
  addition of this support is expected.
 

  

     

     
answer written or last revised on ( 7-OCT-1999 )
     
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