HP OpenVMS Systems

Device and volume security questions?

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The Question is:

 
Could you shed some more information on security protection for devices.  A
disk DEVICE has protection  Read Write Physical I/O and Logical I/O
attributes while the VOLUME has RWED protection attributes.
 
  When are the DEVICE attributes checked or used when accessing a device?
The Security manual discusses checking ACL, volume and file protections when
accessing a file.  Also when would the Physical and Logical attributes be
needed if R,W are available?
   Thank You
 
 
 

The Answer is :

 
  The access flow chart in the OpenVMS Guide to System Security may
  be of interest:
 
    http://www.openvms.digital.com:8000/
    72final/6346/6346pro_001.html#determine_access
 
  In addition to the OpenVMS Guide to System Security, the OpenVMS
  I/O User's Reference Manual may be of interest when considering
  low-level or device-specific information.
 
  The device protection mask and ACL are considered when directly
  assigning a channel to a (non-shareable) device.  This includes
  operations such as mounting and dismounting a storage device,
  directly accessing a terminal device, and similar activities.
 
  Once a storage device is mounted (and marked as shareable), then
  assigning a channel to the device -- an operation that is generally
  transparently performed by OpenVMS without an explicit application
  request -- takes into account the file system's volume-level and
  file-level protections, and not the device-level protections.
 
  The specific meaning of logical and physical access varies by
  the device -- there are three general classes of access when
  considering disks: virtual, logical, and physical.  Virtual I/O
  refers to block-oriented accesses via the file system, such as
  the third block of a particular file.  On most modern disks, the
  logical and physical I/O operations are treated similarly, and
  refer to direct access to specified disk blocks without regard to
  the file system.
 
  The OpenVMS Wizard will assume this question is not one of idle
  curiosity, but no statement of the particular problem or situation
  was included...
 

  

     

     
answer written or last revised on ( 12-OCT-1999 )
     
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