mClock configuration

The mClock profiles hide the low-level details from users, making it easier to configure and use mClock.

The following input parameters are required for an mClock profile to configure the quality of service (QoS) related parameters:
  • The total capacity of input and output operations per second (IOPS) for each Ceph OSD. This is determined automatically.
  • The maximum sequential bandwidth capacity (MiB/s) of each OS. See osd_mclock_max_sequential_bandwidth_[hdd/ssd] option.
  • An mClock profile type to be enabled. The default is balanced.

Using the settings in the specified profile, a Ceph OSD determines and applies the lower-level mClock and Ceph parameters. The parameters applied by the mClock profile make it possible to tune the QoS between the client I/O and background operations in the OSD.