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EMC: SRDF operations
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:Title:        EMC: SRDF operations
:Author:       Douglas O'Leary <dkoleary@olearycomputers.com>
:Description:  EMC: SRDF operations
:Date created: 06/2001 
:Date updated: 07/2005
:Disclaimer:   Standard: Use the information that follows at your own risk.  If you screw up a system, don't blame it on me...

*  Composite SRDF commands


   *  Failover:

      *  Actions:

         *  Write disables (WD) R1
         *  Sets link to Not Ready (NR)
         *  Write enables R2

      *  Command: ``symrdf -g ${group} failover``

   *  Update: Helps to speed up the failback operation by copying invalid 
      tracks before write disabling any disks.

      *  Actions:

         *  Leaves service state as is.
         *  Merges the tracks
         *  Copies invalid tracks

      *  Command: ``symrdf -g ${group} update``

   *  Failback:

      *  Actions: 

         *  Write disables R2
         *  Suspends RDF link
         *  Merges the disk tracks.
         *  Resumes the link
         *  Write enables R1
         *  Copies the changed data

      *  Command: ``symrdf -g ${group} failback``

   *  Split: Leaves both R1 & R2 in write enabled state.

      *  Actions:

         *  Suspends the rdf link.
         *  Write enables R2

      *  Command: ``symrdf -g ${group} split``

   *  Establish:

      *  Actions:

         *  Write disables R2
         *  Suspends the rdf link
         *  Copies data from R1 to R2
         *  Resumes the rdf link.

      *  Command: ``symrdf -g ${group} [ -full ] establish``

   *  Restore: Copies data from R2 to R1

      *  Actions:

         *  Write disables both R1 & R2
         *  Suspends the rdf link.
         *  Merges the track tables
         *  Resumes the rdf link.
         *  Write enables R1

      *  Command: ``symrdf -g ${group} [ -full ] restore``

*  Singular SRDF commands

   *  Suspend: ``symrdf -g ${group} suspend``
   *  Resume: ``symrdf -g ${group} resume``
   *  Set mode:: 

         symrdf -g ${group} set mode sync
         symrdf -g ${group} set domino on
         symrdf -g ${group} set acp_disk skew 1000