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SCSI unit and disk device names?

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The Question is:

If I change the physical SCSI ID of the system disk, will this affect the
 operation of VMS?

The Answer is :

  Other than all that changing the system disk device name entails, no.
  If, for instance, you change the system disk at SCSI unit zero to SCSI
  unit one, then the physical device name of the disk will change from
  DKA0: to DKA100:.  While OpenVMS will function with this, many sites
  choose to hard-code device names, and this can lead to problems.
  Before you fix the physical disk device name references likely found
  within the site-specific software, you will want to learn about logical
  names and particularly about how to set up and how to use logical names.
  In this case, using the logical name created from the volume label
  (eg: DISK$volumelabel) or creating and using a site-specific logical
  name for the specific disk would be an obvious choice for the process
  of replacement, rather than changing the current references over to the
  new physical device name.
  If there is no old device of the same name in the new configuration, you
  could also define a logical name to reference the new device by the old
  name.  Based on the previous example, you would define the DKA0 logical
  name to translate to DKA100.  This approach is not recommended by the
  OpenVMS Wizard, as it simply delays the problem and can lead to other
  oddities, such as the odd behaviour after a new DKA0 device is added.

answer written or last revised on ( 21-OCT-2002 )

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