The DataDomain Auto Image Replication (AIR) import phase is slow

Problem

The replication of backup images is fast and is consistent from the time of the initial configuration. However, the import phase at the destination NetBackup domain becomes slow when using DataDomain.

Error Message

NetBackup install_path/netbackup/logs/bpdm log, on the import media server flags a PERFORMANCE ALERT due to the iterate for partial_filename search:

16:18:39.739 [26846] <4> 15586093:bptm:26846:import-med01: [68DE:185D580] ddp_stat() failed, Path AIR_PRDD01_DRDD02_B/BackupClient-1_1471219635_C1_IM:1471219635:BEOST:2:5::, Err: 5004-nfs lookup failed (nfs: No such file or directory)
16:18:39.740 [26846] <4> 15586093:bptm:26846:import-med01: [68DE:185D580] ddp_stat() failed, Path AIR_PRDD01_DRDD02_B/BackupClient-1_1471219635_C1_IM:1471219635:BEOST:2:4::, Err: 5004-nfs lookup failed (nfs: No such file or directory)
16:18:39.740 [26846] <4> 15586093:bptm:26846:import-med01: /usr/openv/lib/ost-plugins/libstspiDataDomain.so:stspi_get_pathname PERFORMANCE ALERT storage unit iterate for partial_filename AIR_PRDD01_DRDD02_B/BackupClient-1_1471219635_C1_IM:1471219635::0:0::
16:33:38.419 [26846] <4> 15586093:bptm:26846:import-med01: [68DE:185D580] resolve_filename found -> returning result: 0 count: 650948 full_filename 'BackupClient-1_1471219635_C1_IM:1471219635:RMAN_BKP:4:1::'

Cause

The Image Metadata (IM) fragment is used to populate the NetBackup Image Database. NetBackup stores the disk fragment with the NetBackup backup policy name during the initial backup on DataDomain and this is replicated to the destination Logical Storage Unit (LSU). This speeds up the search of fragments on the DataDomain LSU in general.

Example:

The fragment list for the backup image, BackupClient-1_1471219635, on the destination LSU when issuing the command below is:

#ddboost storage-unit show [storage-unit]

BackupClient-1_1471219635_C1_HDR:1471219635:RMAN_BKP:4:1::
BackupClient-1_1471219635_C1_TIR:1471219635:RMAN_BKP:4:1::
BackupClient-1_1471219635_C1_F1:1471219635:RMAN_BKP:4:1::
BackupClient-1_1471219635_C1_IM:1471219635:RMAN_BKP:4:1::

The backup policy is RMAN_BKP.

The initial search in the bpdm log references the generic policy, BEOST, which subsequently fails the initial search with the message below which leads to the iterate for partial_filename search error in the log:

Err: 5004-nfs lookup failed (nfs: No such file or directory).

Solution

Upgrade the DataDomain plugin to 3.0.2.0 or higher depending on the compatibility with NetBackup version and DataDomain OS.

Applies:
DataDomain Plugin 3.0.1.0
DataDomain OS 5.7