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Why "volume show" shows a value greater than 0 for "Space Saved by Deduplication" even if volume efficiency policy is not set ?
https://kb.netapp.com/on-prem/ontap/DM/Efficiency/Efficiency-KBs/Why_volume_show_shows_a_value_greater_than_0_for_Space_Saved_by_Deduplication_even_if_volume_efficiency_policy_is_not_set
This is expected behavior when using ODX for copy offload on storage virtual machine (SVM) , because ODX uses deduplication as part of copy process. In this case, "volume efficiency show" command show...This is expected behavior when using ODX for copy offload on storage virtual machine (SVM) , because ODX uses deduplication as part of copy process. In this case, "volume efficiency show" command shows volume efficiency policy is disabled. ::> volume efficiency show However, "volume show" output shows value grater than 0kb at "Space Saved by Deduplication". ::> volume show -volume vol1 Space Saved by Storage Efficiency: 768KB Space Saved by Deduplication: 768KB
SIS scan is extremely slow at gathering phase
https://kb.netapp.com/on-prem/ontap/OHW/OHW-KBs/SIS_scan_is_extremely_slow_at_gathering_phase
SIS scan is extremely slow at Gathering phase. SIS log just stops at Compressing and there is no further recording for slow scan task. Tue Dec 15 10:51:35 2020 [Vserver UUID: 60a25723-700f-11e7-96c7-x...SIS scan is extremely slow at Gathering phase. SIS log just stops at Compressing and there is no further recording for slow scan task. Tue Dec 15 10:51:35 2020 [Vserver UUID: 60a25723-700f-11e7-96c7-xxxxxxxxxxxx] /vol/volname [sid: 1607997095] Begin (sis start scan) Tue Dec 15 10:51:35 2020 [Vserver UUID: 60a25723-700f-11e7-96c7-xxxxxxxxxxxx] /vol/volname [sid: 0] Info (Optimized scan)
Volume efficiency stale fingerprints show greater than 20%
https://kb.netapp.com/on-prem/ontap/Ontap_OS/OS-KBs/Volume_efficiency_stale_fingerprints_show_greater_than_20
Applies to ONTAP 9 Volume efficiency (deduplication) Issue A volume may show stale fingerprints in excess of 20%: Cluster01::*> volume efficiency show -vserver svm1 -volume vol1 Vserver Name: svm1 Vol...Applies to ONTAP 9 Volume efficiency (deduplication) Issue A volume may show stale fingerprints in excess of 20%: Cluster01::*> volume efficiency show -vserver svm1 -volume vol1 Vserver Name: svm1 Volume Name: vol1 Volume Path: /vol/vol1 State: Enabled Status: Active Stale Fingerprint Percentage: 24
Scheduled deduplication job stops at saving_sharing phase
https://kb.netapp.com/on-prem/ontap/OHW/OHW-KBs/Scheduled_deduplication_stops_at_saving_sharing_phase
Fri Nov 27 00:00:00 2020 [Vserver UUID: de5d877b-eb36-xxxx-xxxx-xxxxxxxx] /vol/vol1 [sid: 0] Info (sis start schedule) Sat Nov 28 00:00:00 2020 [Vserver UUID: de5d877b-eb36- xxxx-xxxx-xxxxxxxx] /vol/v...Fri Nov 27 00:00:00 2020 [Vserver UUID: de5d877b-eb36-xxxx-xxxx-xxxxxxxx] /vol/vol1 [sid: 0] Info (sis start schedule) Sat Nov 28 00:00:00 2020 [Vserver UUID: de5d877b-eb36- xxxx-xxxx-xxxxxxxx] /vol/vol1 [sid: 0] Info (sis start schedule) Sun Nov 29 00:00:00 2020 [Vserver UUID: de5d877b-eb36- xxxx-xxxx-xxxxxxxx] /vol/vol1 [sid: 0] Info (sis start schedule) Mon Nov 30 00:00:00 2020 [Vserver UUID: de5d877b-eb36- xxxx-xxxx-xxxxxxxx] /vol/vol1 [sid: 0] Info (sis start schedule)
High response times for volumes on SATA or SAS disks when workload increases (Performance Capacity beyond critical threshold)
https://kb.netapp.com/on-prem/ontap/Perf/Perf-KBs/High_response_times_for_volumes_on_SATA_or_SAS_disks_when_workload_increases_Performance_Capacity_beyond_critical_threshold
The article cover what causes high response times for volumes on SATA or SAS disks when workload increases and what you need to do to reduce, stagger, or monitor workloads causing high disk latency an...The article cover what causes high response times for volumes on SATA or SAS disks when workload increases and what you need to do to reduce, stagger, or monitor workloads causing high disk latency and utilization.
Client applications report higher space usage than ONTAP
https://kb.netapp.com/on-prem/ontap/Ontap_OS/OS-KBs/Client_applications_report_higher_space_usage_than_ONTAP
Applies to ONTAP 9 Issue Client applications, such as databases or hypervisors, report a high amount of space used in a volume. ONTAP df output shows far less space used.
How to limit the maximum number of post-process compression and deduplication processes running in parallel
https://kb.netapp.com/on-prem/ontap/Perf/Perf-KBs/How_to_limit_the_maximum_number_of_post-process_compression_and_deduplication_processes_running_in_parallel
Applies to Clustered Data ONTAP 8 ONTAP 9 Description Under certain conditions, it becomes necessary to limit the maximum number of post-process volume efficiency operations that run in parallel on a ...Applies to Clustered Data ONTAP 8 ONTAP 9 Description Under certain conditions, it becomes necessary to limit the maximum number of post-process volume efficiency operations that run in parallel on a ONTAP node.
Huge difference between source and destination snapshot size
https://kb.netapp.com/on-prem/ontap/DP/SnapMirror/SnapMirror-KBs/Huge_difference_between_source_and_destination_snapshot_size
Applies to ONTAP 9 Snapmirror Single Instance Storage (SIS) deduplication Issue Checking snapshot size on source and destination a huge difference in size can be noticed On destination snapshot size a...Applies to ONTAP 9 Snapmirror Single Instance Storage (SIS) deduplication Issue Checking snapshot size on source and destination a huge difference in size can be noticed On destination snapshot size a snapshot spill can be seen. Even though all stale snapshots on destination have been deleted and destination has the same snapshots with source , the difference is still huge.
System Manager reports much more logical space than ONTAP CLI
https://kb.netapp.com/on-prem/ontap/DM/System_Manager/SM-KBs/System_Manager_reports_much_more_logical_space_than_ONTAP_CLI
Applies to System Manager 9.8 ONTAP 9 Storage Efficiency Issue The capacity panel on System Manager's dashboard page reports much more logical space used than the ONTAP CLI For example, the capacity p...Applies to System Manager 9.8 ONTAP 9 Storage Efficiency Issue The capacity panel on System Manager's dashboard page reports much more logical space used than the ONTAP CLI For example, the capacity panel could show 75TB of logical data, while a volume show -fields logical-used command does not add to anywhere near this amount
Volume efficiency start failing with error Compression is not enabled. Use of options -a and -b is not valid
https://kb.netapp.com/on-prem/ontap/Ontap_OS/OS-KBs/Volume_efficiency_start_failing_with_error_Compression_is_not_enabled._Use_of_options_-a_and_-b_is_not_valid
Warning: This operation scans all of the data in volume "vol1" of Vserver "svm1". It might take a significant time, and degrade performance during that time. Use of "-snapshot-blocks|-b" option can in...Warning: This operation scans all of the data in volume "vol1" of Vserver "svm1". It might take a significant time, and degrade performance during that time. Use of "-snapshot-blocks|-b" option can increase space usage as data which is part of Snapshot will be compressed. Error: command failed: Failed to start efficiency on volume "vol1" of Vserver "svm1": Compression is not enabled. Use of options -a and -b is not valid.
High CPU utilization from exempt domain with a number of [f] processes
https://kb.netapp.com/on-prem/ontap/Perf/Perf-KBs/High_CPU_utilization_from_exempt_domain_with_a_number_of_f_processes
Applies to ONTAP 9 SnapMirror Single Instance Storage (SIS) Issue CPUs are constantly saturated on SnapMirror destination. The high CPU utilization is from the exempt domain. "f" processes is constant...Applies to ONTAP 9 SnapMirror Single Instance Storage (SIS) Issue CPUs are constantly saturated on SnapMirror destination. The high CPU utilization is from the exempt domain. "f" processes is constantly running. Example: PS-AXRHWWW output from ASUP. USER PID %CPU %MEM VSZ RSS TT STAT STARTED TIME UID PPID CPU PRI NI MWCHAN VCTX COMMAND root 12623 35.4 0.0 0 28 - RL 12:07AM 6:42.26 0 0 894 12 0 - 0 [f]