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 sbcli-pre 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:

sbcli-pre lvol create \
  --max-rw-iops MAX_RW_IOPS 3500 \
  --max-rw-mbytes MAX_RW_MBYTES 125 \
  <VOLUME_NAME> \
  <VOLUME_SIZE> \
  <POOL_NAME>

Parameters

Parameter	Description	Default
--max-rw-iops MAX_RW_IOPS	Maximum IO operations per second.	0
--max-rw-mbytes MAX_RW_MBYTES	Maximum read/write throughput.	0
--max-r-mbytes MAX_R_MBYTES	Maximum read throughout.	0
--max-w-mbytes MAX_W_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:

sbcli-pre lvol qos-set \
  --max-rw-iops MAX_RW_IOPS 5000 \
  --max-rw-mbytes MAX_RW_MBYTES 250 \
  <VOLUME_UUID>

Verification

To check the current QoS settings:

sbcli-pre lvol get <VOLUME_UUID>

Review the output for the active QoS configuration.