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Title
DAR restore go into loop when spanning tapes on large NetApp NDMP backups -
Description
When restoring large NDMP backups taken on NetApp filer and the backup spans tapes we see restore go into loop loading the same tape trying to restore the data and reloading the same tape again trying again to restore. When it should be loading the next tape in the backup that contains the remaining data desired for restore.
“WINDOW length 6458118111232 (0x5dfa5d60000) invalid -- changing to INFINITY” entries are seen inNetVault the log on each attempt to restore
Extract from binary log:
Job Message 2020/05/20 07:37:23 3535 Media NVserver (Netapp-cluster-node) Job has been assigned media '007398L7' <NDMP-Group> in 'DRIVE 2:Netapp-filer'
Job Message 2020/05/20 07:38:16 3535 Media NVserver (Netapp-cluster-node) Media in 'DRIVE 2:Netapp-filer' assigned to job ready for data transfer
Background 2020/05/20 07:38:16 3535 Media NVserver Mover set window: residue blocks
Warning 2020/05/20 07:38:16 3535 Media NVserver NDMP: WARNING 6: MOVER: WINDOW length 6458118111232 (0x5dfa5d60000) invalid -- changing to INFINITY
Information 2020/05/20 07:38:17 3535 Data Plugin NVserver Cluster affinity match between volume & device; performing 'local' data transfer.
Information 2020/05/20 07:38:36 3535 Data Plugin NVserver NDMP: NORMAL 7: DIRECT ACCESS RECOVERY (DAR) requested
Information 2020/05/20 08:02:01 3535 Data Plugin NVserver NDMP: NORMAL 9: MOVER: signaling EOF at 6458118111232 to 10110405181440 on SEEK FSR
Information 2020/05/20 08:02:02 3535 Media NVserver (Netapp-cluster-node) Media identified as '007398L7' <NDMP-Group>
Information 2020/05/20 08:02:02 3535 Media NVserver (Netapp-cluster-node) Media in 'DRIVE 2:Netapp-filer' with affinity '7807526a-9db2-11e5-b486-63711f743857' ready for data transfer
Warning 2020/05/20 08:02:02 3535 Data Plugin NVserver NDMP: WARNING 10: MOVER: WINDOW length 6458118111232 (0x5dfa5d60000) invalid -- changing to INFINITY
Information 2020/05/20 08:20:11 3535 Data Plugin NVserver NDMP: NORMAL 12: MOVER: signaling EOF at 6458118111232 to 10110405181440 on SEEK FSR
NetApp bug id 1352800
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Cause
NetApp bug 1352800 “Direct access recovery (DAR) might fail when mover window length is greater than 4TB”
See NetApp bug link below:
https://mysupport.netapp.com/NOW/cgi-bin/bol?Type=Detail&Display=1352800
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Resolution
Apply NetApp patch when available, release is expected at end of January or early February 2021
The patch will be available for OnTap 9.5 and later so there will have a patch available for OnTap 9.7 when released.
Workaround
Until NetApp patch for effected OnTap versions is available None-DAR restore option need to be used.