IT11274: DOCUMENTATION MISSING FOR "SYNCRATE" PARAMETER

APAR status

• Closed as documentation error.

Error description

• Knowledge center site doesn't describe the "syncrate" parameter.
  TPC "transform storage" tasks such as adding a mirrored vdisk
  copy, or migrating volumes from one pool to another via the
  storage optimizer functions, perform these tasks by default with
  a sync rate of 100%.  This can cause a performance problems on
  all SVC volumes.
  This setting is configurable via TPCTOOL commands but is not
  documented.
  To confirm TPC's current setting:
  <tpc-install>/cli/tpctool getdscfg -user <tpcadmin-user> -pwd
  <tpcadmin-user-password>  -url <url of tpc server, eg.
  'localhost:9550'> -property OptAutoController.SyncRate -context
  DeviceServer
  if the output is like below:
  Property                   Context      Value
  =============================================
  OptAutoController.SyncRate DeviceServer -
  it means the configuration setting has the default value of 100.
  To alter the syncrate (globally) in TPC:
  <tpc-install>/cli/tpctool setdscfg -user <tpcadmin-user> -pwd
  <tpcadmin-user-password>  -url <url of tpc server, eg.
  'localhost:9550'> -property OptAutoController.SyncRate -context
  DeviceServer 50
  To verify that the setting was modified, run the getdscfg
  command again:
  <tpc-install>/cli/tpctool getdscfg -user <tpcadmin-user> -pwd
  <tpcadmin-user-password>  -url <url of tpc server, eg.
  'localhost:9550'> -property OptAutoController.SyncRate -context
  DeviceServer
  The new command output should look like below:
  Property                   Context      Value
  =============================================
  OptAutoController.SyncRate DeviceServer 50
  The Device Server must be restarted, for the setting to take
  effect.
  RECREATE STEPS:  N/A
  ________________________________________________________________
  DB2 Version used for Server:    N/A
  The defect is against component:   5608TPC00
  Server/Manager build/release (TPC):   5.2.x
  ________________________________________________________________
  Problem as described by customer:   N/A
  Initial customer impact (low/med/high): Med
  

Local fix

• Manually alter syncrate parameter
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * TPC 5.2.x users with SVC or Storwize family systems          *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * Performance problems on SAN Volume Controller volumes when   *
  * the synchronization rate is set to 100% (default).   See     *
  * ERROR DESCRIPTION.                                           *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Refer to details in this technote to adjust the syncrate     *
  * parameter:                                                   *
  * http://www.ibm.com/support/docview.wss?uid=swg21972452       *
  ****************************************************************
  

Problem conclusion

• View the technote on changing the synchronization rate for
  volumes on SVC and Storwize family systems.
  http://www.ibm.com/support/docview.wss?uid=swg21972452
  
  
  
  The synchronization rate on SAN Volume Controller is the rate at
  which the volume copies synchronize again after synchronization
  is lost.
  
  IBM Spectrum Control can do tasks that significantly alter the
  structure of storage. For example, IBM Spectrum Control can add
  a mirrored volume copy, or migrate volumes from one pool to
  another by using the storage optimizer functions. When IBM
  Spectrum Control does these tasks, by default, the
  synchronization rate is set to 100%.
  
  The synchronization rate can cause performance problems on all
  SAN Volume Controller volumes. However, you can use the tpctool
  command to change the synchronization rate.
  
  To verify the current synchronization rate, go the
  installation_dir\cli directory, then use the getdscfg command:
  
  tpctool getdscfg -user admin_user_id -pwd admin_user_password
  -url localhost:9550 -property OptAutoController.SyncRate
  -context DeviceServer
  
  If the synchronization rate is set to the default value of 100%,
  the tpctool command shows the following information:
  
  Property                   Context      Value
  =============================================
  OptAutoController.SyncRate DeviceServer -
  
  To set the value of the synchronization rate to 50%, use the
  setdscfg command:
  
  tpctool setdscfg -user admin_user_id -pwd admin_user_password
  -url localhost:9550 -property OptAutoController.SyncRate
  -context DeviceServer 50
  
  The new synchronization rate is used for all SAN Volume
  Controller or Storwize family resources that are you add to IBM
  Spectrum Control. You cannot set this value independently for
  each resource.
  
  To verify that the value of the synchronization rate is
  modified, use the getdscfg command again. If the synchronization
  rate is set to 50%, the tpctool command shows the following
  information:
  
  Property                   Context      Value
  =============================================
  OptAutoController.SyncRate DeviceServer 50
  
  After you modify the value of the synchronization rate, stop and
  restart the Device server.
  

Temporary fix

Comments

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Fix information

Applicable component levels