IT34499: INCREMENTAL BACKUP EXCESSIVE SCAN TIME FOR MICROSOFT WINDOWS FILE SYSTEMS CONFIGURED FOR MICROSOFT DATA DEDUPLICATION

IBM Spectrum Protect Client 8.1.11 Downloads and READMEs

APAR status

• Closed as program error.

Error description

• When the backup-archive client is used for incremental backup of
  a Windows file system that is configured for Microsoft data
  deduplication, the elapsed processing time can seem excessive.
  This is especially noticeable when the number of changed files
  is small, and when most of the files are deduplicated.
  
  Note: The planned fix for this APAR addresses a problem during
  scanning for changed files. The behavior for deduplicated file
  systems, described
  inhttps://www.ibm.com/support/pages/support-microsoft-deduplicat
  ion-enabled-volumes, is not changed.
  
  Initial Impact: Medium
  
  IBM Spectrum Protect versions affected:
  Spectrum Protect Backup-Archive Client for Microsoft Windows
  versions 7.1 and 8.1
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * IBM Spectrum Protect BA Client v716, v718, v814, v816, v818, *
  * v819 and, v8110 on the Windows platform.                     *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * See Error Description                                        *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * This issue is projected to be fixed in the IBM Spectrum      *
  * Protect Backup-Archive client 8.1.11 version on Windows      *
  * platform.                                                    *
  * Note that this is subject to change at the discretion of     *
  * IBM.                                                         *
  ****************************************************************
  

Problem conclusion

• When the backup-archive client is used for incremental backup
  of a Windows file system that is configured for Microsoft data
  deduplication, the elapsed processing time can seem excessive.
  From Spectrum Protect Backup/Archive client point view the
  Microsoft deduplication feature is transparent to the client.
  The client backs up the data from these volumes as a
  Non-Optimized backup. That means that the data is rehydrated by
  the MicroSoft Data Deduplication feature and saved to the Tivoli
  Storage Manager Server as full size data. The conversion
  (rehydration) from optimized file to normal file is performed
  transparently in memory by the data deduplication feature when
  the the client works with the files.
  The backup operation can be divided into two phases:
  1. scanning file system to find candidates for backup;
  2. sending files to the TSM server
  and the conversion (redhydration) from optimized file to normal
  file happens twice: the first time at scanning phase and the
  second time is at sending phase.
  The rehydration at the first phase can be avoided and it allows
  to improve the performance on dedup disks.
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Modules/Macros

• DSM      DSMC     DSMCSVC  DSMAGENT
  

Fix information

• Fixed component name

  TSM CLIENT

• Fixed component ID

  5698ISMCL

Applicable component levels

• R81W PSY

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