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Advanced O&M Command Reference

OceanStor 18000 and 18000F V5 Series V500R007

This document is applicable to OceanStor 18500 V5, 18800 V5, 18500F V5, and 18800F V5. Based on the CLI, this document describes how to use various commands classified by functionsand how to set the CLI and manage the storage system through these commands.

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change hyper_metro_pair write_mode

change hyper_metro_pair write_mode


The change hyper_metro_pair write_mode command is used to set the write mode of a HyperMetro pair to tune the performance of HyperMetro IO lock.


change hyper_metro_pair write_mode pair_id=? write_mode=? [ prefetch_mode=? | prefetch_size=? ]





pair_id=? ID of the HyperMetro pair.

Run the "show hyper_metro_pair general" command without any parameters to obtain the value.

write_mode=? Write mode of host.

The value is "none" or "sequential" or "reverse" or "random", where:

  • "none": none I/O write mode.
  • "sequential": sequential I/O write mode.
  • "reverse": reverse I/O write mode.
  • "random": random I/O write mode.
prefetch_mode=? Prefetch mode.

The value is "max" or "scale" or "block_kb" or "block_mb" or "block_gb", where:

  • "max": max prefetch size,only for "sequential" and "reverse" write mode.
  • "scale": prefetch by a scale of io size.
  • "block_kb": prefetch by a fixed size in KB.
  • "block_mb": prefetch by a fixed size in MB.
  • "block_gb": prefetch by a fixed size in GB.
prefetch_size=? Prefetch size.



Developer view, Engineer view

Usage Guidelines



Set write mode as random, and the max prefetch size is 64 KB for a HyperMetro pair whose ID is "1".

engineer:/>change hyper_metro_pair write_mode pair_id=1 write_mode=random prefetch_mode=block_kb prefetch_size=64
Command executed successfully.

System Response


Updated: 2020-01-17

Document ID: EDOC1000181602

Views: 762259

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