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How does Temperature Sensitive Storage Efficiency affect SnapMirror?

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Applies to

  • SnapMirror
  • Temperature Sensitive Storage Efficiency (TSSE)

Answer

  • Temperature Sensitive Storage Efficiency is a method of compressing data based on data "temperature", or how often the data is used
  • "Cold" data, or data that is not used often, is recompressed with a higher compression ratio for increased storage efficiency

Additional Information

Default Configurations in ONTAP
  • TSSE is enabled for new volumes on AFF platforms running ONTAP 9.8 through ONTAP 9.9.1
  • In ONTAP 9.10.1 and later, TSSE is no longer default for new volumes on AFF platforms and must be enabled explicitly on volume creation
  • In ONTAP 9.10.1 and later, TSSE is enabled when storage-efficiency-mode on a volume is set to efficient
  • TSSE is available for existing volumes on AFF platforms running ONTAP 9.10.1 and later
SnapMirror Interactions
  • TSSE settings are inherited by SnapMirror destination volumes and the SnapMirror relationship will maintain deduplication and compression savings from the source volume with some exceptions (see the next section)
  • No steps are needed to enable TSSE on SnapMirror destination volumes if supported by the ONTAP release and platform
  • When replicating TSSE volumes to a ONTAP 9.6 or earlier destination, SnapMirror may fail with "Invalid data operation(Replication engine error)" or "Failed to start transfer. (Operation not supported)" see BUG 1384963 for more details and fixed releases. This issue does not occur with ONTAP 9.7 or later destinations
  • If replicating from a TSSE volume to a destination in ONTAP 9.7 or earlier, compression savings will be lost over the network. SnapMirror will continue to maintain deduplication savings
  • TSSE is not compatible with FabricPool until ONTAP 9.10.1. If replicating from a TSSE SnapMirror source volume to a FabricPool SnapMirror destination running a release earlier than ONTAP 9.10.1, compressed blocks are decompressed at the destination before being tiered by FabricPool
SnapMirror Destination Compression Savings
  • TSSE requires contiguous Block Numbers to write data with compression successfully on a SnapMiror destination
  • In cases where contiguous Block Numbers are not available, data may be written to SnapMirror destination volumes uncompressed or with reduced compression savings
  • The typical scenarios where this occurs are:
    • The destination aggregate is low on space. Maintaining ample free space on the destination aggregate can avoid losing compression savings with TSSE
    • The destination aggregate is aged, meaning the aggregate and volumes within the aggregate have existed for a long period of time, resulting in fewer contiguous Block Numbers

Notes:

Even if the current environment does not meet the scenarios mentioned above, it cannot guarantee that the SnapMirror destination volume will maintain 100% of the compression savings from the source volume, TSSE will handle it automatically based on the real situation.

NetApp provides no representations or warranties regarding the accuracy or reliability or serviceability of any information or recommendations provided in this publication or with respect to any results that may be obtained by the use of the information or observance of any recommendations provided herein. The information in this document is distributed AS IS and the use of this information or the implementation of any recommendations or techniques herein is a customer's responsibility and depends on the customer's ability to evaluate and integrate them into the customer's operational environment. This document and the information contained herein may be used solely in connection with the NetApp products discussed in this document.