:Type: 64-bit Integer
:Required: No
:Default: ``50 MiB``
+
+
+RBD Features
+============
+
+RBD supports advanced features which can be specified via the command line when creating images or the default features can be specified via Ceph config file via 'rbd_default_features = <sum of feature numeric values>' or 'rbd_default_features = <comma-delimited list of CLI values>'
+
+``Layering``
+
+:Description: Layering enables you to use cloning.
+:Internal value: 1
+:CLI value: layering
+:Added in: v0.70 (Emperor)
+:KRBD support: since v3.10
+:Default: yes
+
+``Striping v2``
+
+:Description: Striping spreads data across multiple objects. Striping helps with parallelism for sequential read/write workloads.
+:Internal value: 2
+:CLI value: striping
+:Added in: v0.70 (Emperor)
+:KRBD support: since v3.10
+:Default: yes
+
+``Exclusive locking``
+
+:Description: When enabled, it requires a client to get a lock on an object before making a write. Exclusive lock should only be enabled when a single client is accessing an image at the same time.
+:Internal value: 4
+:CLI value: exclusive-lock
+:Added in: v0.92 (Hammer)
+:KRBD support: since v4.9
+:Default: yes
+
+``Object map``
+
+:Description: Object map support depends on exclusive lock support. Block devices are thin provisioned—meaning, they only store data that actually exists. Object map support helps track which objects actually exist (have data stored on a drive). Enabling object map support speeds up I/O operations for cloning; importing and exporting a sparsely populated image; and deleting.
+:Internal value: 8
+:CLI value: object-map
+:Added in: v0.93 (Hammer)
+:KRBD support: no
+:Default: yes
+
+
+``Fast-diff``
+
+:Description: Fast-diff support depends on object map support and exclusive lock support. It adds another property to the object map, which makes it much faster to generate diffs between snapshots of an image, and the actual data usage of a snapshot much faster.
+:Internal value: 16
+:CLI value: fast-diff
+:Added in: v9.0.1 (Infernalis)
+:KRBD support: no
+:Default: yes
+
+
+``Deep-flatten``
+
+:Description: Deep-flatten makes rbd flatten work on all the snapshots of an image, in addition to the image itself. Without it, snapshots of an image will still rely on the parent, so the parent will not be delete-able until the snapshots are deleted. Deep-flatten makes a parent independent of its clones, even if they have snapshots.
+:Internal value: 32
+:CLI value: deep-flatten
+:Added in: v9.0.2 (Infernalis)
+:KRBD support: no
+:Default: yes
+
+
+``Journaling``
+
+:Description: Journaling support depends on exclusive lock support. Journaling records all modifications to an image in the order they occur. RBD mirroring utilizes the journal to replicate a crash consistent image to a remote cluster.
+:Internal value: 64
+:CLI value: journaling
+:Added in: v10.0.1 (Jewel)
+:KRBD support: no
+:Default: no
+
+
+``Data pool``
+
+:Description: On erasure-coded pools, the image data block objects need to be stored on a separate pool from the image metadata.
+:Internal value: 128
+:Added in: v11.1.0 (Kraken)
+:KRBD support: since v4.11
+:Default: no
+
+
+``Operations``
+
+:Description: Used to restrict older clients from performing certain maintenance operations against an image (e.g. clone, snap create).
+:Internal value: 256
+:Added in: v13.0.2 (Mimic)
+:KRBD support: since v4.16
+
+
+``Migrating``
+
+:Description: Used to restrict older clients from opening an image when it is in migration state.
+:Internal value: 512
+:Added in: v14.0.1 (Nautilus)
+:KRBD support: no
+
+
+RBD QOS Settings
+================
+
+RBD supports limiting per image IO, controlled by the following
+settings.
+
+``rbd qos iops limit``
+
+:Description: The desired limit of IO operations per second.
+:Type: Unsigned Integer
+:Required: No
+:Default: ``0``
+
+
+``rbd qos bps limit``
+
+:Description: The desired limit of IO bytes per second.
+:Type: Unsigned Integer
+:Required: No
+:Default: ``0``
+
+
+``rbd qos read iops limit``
+
+:Description: The desired limit of read operations per second.
+:Type: Unsigned Integer
+:Required: No
+:Default: ``0``
+
+
+``rbd qos write iops limit``
+
+:Description: The desired limit of write operations per second.
+:Type: Unsigned Integer
+:Required: No
+:Default: ``0``
+
+
+``rbd qos read bps limit``
+
+:Description: The desired limit of read bytes per second.
+:Type: Unsigned Integer
+:Required: No
+:Default: ``0``
+
+
+``rbd qos write bps limit``
+
+:Description: The desired limit of write bytes per second.
+:Type: Unsigned Integer
+:Required: No
+:Default: ``0``
+
+
+``rbd qos iops burst``
+
+:Description: The desired burst limit of IO operations.
+:Type: Unsigned Integer
+:Required: No
+:Default: ``0``
+
+
+``rbd qos bps burst``
+
+:Description: The desired burst limit of IO bytes.
+:Type: Unsigned Integer
+:Required: No
+:Default: ``0``
+
+
+``rbd qos read iops burst``
+
+:Description: The desired burst limit of read operations.
+:Type: Unsigned Integer
+:Required: No
+:Default: ``0``
+
+
+``rbd qos write iops burst``
+
+:Description: The desired burst limit of write operations.
+:Type: Unsigned Integer
+:Required: No
+:Default: ``0``
+
+
+``rbd qos read bps burst``
+
+:Description: The desired burst limit of read bytes.
+:Type: Unsigned Integer
+:Required: No
+:Default: ``0``
+
+
+``rbd qos write bps burst``
+
+:Description: The desired burst limit of write bytes.
+:Type: Unsigned Integer
+:Required: No
+:Default: ``0``
+
+
+``rbd qos schedule tick min``
+
+:Description: The minimum schedule tick (in milliseconds) for QoS.
+:Type: Unsigned Integer
+:Required: No
+:Default: ``50``
projects / ceph.git / blobdiff