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Defining Quality of Service

Simplyblock allows Quality of Service (QoS) limits to be applied to logical volumes (LVs) to control performance by defining maximum IOPS and throughput. QoS settings can be configured during volume creation or adjusted on an active Logical Volume using the sbctl command line interface.

Configuring QoS allows simplyblock logical volumes to deliver predictable performance by limiting resource consumption and ensuring balanced workload distribution across the storage cluster.

Setting QoS During Volume Creation

QoS can be applied when creating a new logical volume:

sbctl volume add \
  <VOLUME_NAME> \
  <VOLUME_SIZE> \
  <POOL_NAME> \
  --max-rw-iops 3500 \
  --max-rw-mbytes 125

Parameters

Parameter Description Default
--max-rw-iops <IOPS> Maximum I/O operations per second. 0
--max-rw-mbytes <MBYTES> Maximum read/write throughput. 0
--max-r-mbytes <MBYTES> Maximum read throughput. 0
--max-w-mbytes <MBYTES> Maximum write throughput. 0

To see all available parameters when creating a logical volume, see Provisioning.

Changing QoS on an Active Logical Volume

QoS settings can also be updated on an existing logical volume:

sbctl volume qos-set \
  <VOLUME_UUID> \
  --max-rw-iops 5000 \
  --max-rw-mbytes 250

Verification

To check the current QoS settings:

sbctl volume get <VOLUME_UUID>

Review the output for the active QoS configuration.