The following is from the handout for another ADSM session at SHARE 84.
The presenter was Greg Tevis, of ADSM Technical Support.


              Session 5071:  New ADSM Disaster Recovery


Agenda

o  Disaster recovery in ADSM today
o  New roles of ADSM recovery utilities
o  New disaster recovery functions
o  Solutions and recommendations

Note:  Support discussed in this presentation is subject to change.
       Please consult announcement materials as they become available.


ADSM Database Protection Today

o  Database and recovery log mirroring
   +  continuous operations on media failure
   +  improves read performance
   -  doubles storage requirements

o  Online database dump
   +  allows dump while server is online
   -  database audit required on recovery

o  Consistent database dump
   +  does not require database audit on recovery
   -  essentially stops server during dump

o  Export of server definitions
   -  must be used with export of data


ADSM Storage Pool Protection Today

o  Export of storage pool data
   -  extremely slow
   -  not incremental

o  Manual backup of volumes
   -  out of synch with database
   -  tedious for tape volumes
   -  volume management nightmare

o  Backup client data twice
   -  data sent twice across network
   -  management of offsite volumes (if sent to same server)


New Roles of ADSM Recovery Utilities

o  Database and recovery log mirroring
   -  still great for availability and read performance
   -  recommended if not using rollforward
   -  recommended for recovery log if using rollforward

o  Database salvage utilities
   -  still valuable as last resort to save database

o  Export
   -  still useful for information interchange between servers
   -  can be used for backup of server definitions

o  Online database dump
   -  obsolete

o  Consistent database dump
   -  obsolete


ADSM Database Backup Series

o  Full backup plus incrementals

o  ADSM keeps internal backup series and volume numbers

o  Full backup starts new backup series

o  Incrementals limited to 32 to control
   -  recovery log size
   -  recovery time

o  Used to restore to point in time or to most recent state (with
   roll-forward)


ADSM Database Backup

o  Full or incremental backups are run
   -  using BACKUP DB command
   -  using schedules
   -  automatically based on recovery log utilization

o  Full backups are required at times
   -  new, restored, or resized database
   -  32 incrementals reached
   -  log mode changed to ROLLFORWARD
   -  ensure faster recovery

o  Full and incremental backups clear recovery log records


ADSM Database Recovery

o  No database audit required

o  Point in time recovery to any backup
   -  recovery log records needed
   -  storage pool volume audits needed for online and changed volumes

o  Roll forward recovery to most recent state
   -  roll forward log mode increases recovery log size
   -  recovery log records used after last backup
   -  entire database or single volume can be restored
   -  no storage pool volume audits required


Storage Pool Backup and Recovery Highlights

o  Provides means of protecting storage pool data

o  Supports incremental backups of storage pools

o  File level granularity enables many functions

o  Manages primary and backup copies of files
   -  automatically uses backup copies of files
   -  primary copies can be recovered from backup copies

Primary_Pool_Disk + Primary_Pool_Tape = Copy_Pool_Tape ==> Offsite Vault


ADSM Storage Pool Backup

o  A primary pool can use multiple copy pools

o  Multiple primary pools can use one copy pool

o  Only files new to primary storage pool are copied (incremental)

o  Copies made automatically or by command

o  Copy files not moved when primary files moved

o  Reclamation (and Move Data) of offsite volumes copy from primary
   pool


ADSM Storage Pool Recovery

o  Copy file automatically accessed if primary file in error or volume
   unavailable

o  RESTORE VOLUME restores files for primary volumes

o  RESTORE STGPOOL restores damaged files and all files on volumes
   marked DESTROYED

o  AUDIT VOLUME and read errors detect damaged files


Recovery from Media Failures -- Lost storage pool volume

o  Use UPDATE VOLUME to mark UNAVAILABLE

o  Use RESTORE VOLUME (with VOLUMESONLY) to preview which copy volumes
   are needed

o  Bring needed copy volumes onsite and mark READWRITE

o  Issue RESTORE VOLUME command

o  Mark copy volumes OFFSITE and return to vault


Recovery from Media Failures -- Lost database volume

o  Bring back most recent database backup series

o  Allocate database and log space if needed

o  Issue DSMSERV RESTORE DB
   -  uses volume history, devclass and options files to determine
      volumes to mount
   -  can specify point in time
   -  will automatically roll forward if able


Recovery from Disaster

o  Move database and storage pool backups to recovery location

o  Restore volume history, device class and options files and
   allocate database

o  Issue DSMSERV RESTORE DB

o  Mark all primary volumes as DESTROYED using UPDATE VOLUMES
   (wildcarding allowed)

o  Define new volumes to primary storage pools

o  Mark all copy volumes as READWRITE (restore services now available
   to clients)

o  Issue RESTORE STGPOOL for each primary pool


Recommendations

o  Back up database and storage pools regularly

o  Also back up volume history, device class and options files

o  Specify volume history and device class files in options files

o  Roll-forward recovery is valid alternative to database mirroring
   -  perform regular database backups
   -  continue recovery log mirroring
   -  no performance impact for roll-forward

o  Use asynchronous storage pool backups for most cases

o  Perform reclamation on offsite volumes periodically

o  Run RESTORE STGPOOL periodically