What: /sys/bus/rbd/ Date: November 2010 Contact: Yehuda Sadeh , Sage Weil Description: Being used for adding and removing rbd block devices. Usage: [snap name] $ echo "192.168.0.1 name=admin rbd foo" > /sys/bus/rbd/add The snapshot name can be "-" or omitted to map the image read/write. A will be assigned for any registered block device. If snapshot is used, it will be mapped read-only. Removal of a device: $ echo > /sys/bus/rbd/remove What: /sys/bus/rbd/add_single_major Date: December 2013 KernelVersion: 3.14 Contact: Sage Weil Description: Available only if rbd module is inserted with single_major parameter set to true. Usage is the same as for /sys/bus/rbd/add. If present, should be used instead of the latter: any attempts to use /sys/bus/rbd/add if /sys/bus/rbd/add_single_major is available will fail for backwards compatibility reasons. What: /sys/bus/rbd/remove_single_major Date: December 2013 KernelVersion: 3.14 Contact: Sage Weil Description: Available only if rbd module is inserted with single_major parameter set to true. Usage is the same as for /sys/bus/rbd/remove. If present, should be used instead of the latter: any attempts to use /sys/bus/rbd/remove if /sys/bus/rbd/remove_single_major is available will fail for backwards compatibility reasons. Entries under /sys/bus/rbd/devices// -------------------------------------------- client_id The ceph unique client id that was assigned for this specific session. features A hexadecimal encoding of the feature bits for this image. major The block device major number. minor The block device minor number. (December 2013, since 3.14.) name The name of the rbd image. image_id The unique id for the rbd image. (For rbd image format 1 this is empty.) pool The name of the storage pool where this rbd image resides. An rbd image name is unique within its pool. pool_id The unique identifier for the rbd image's pool. This is a permanent attribute of the pool. A pool's id will never change. size The size (in bytes) of the mapped block device. refresh Writing to this file will reread the image header data and set all relevant datastructures accordingly. current_snap The current snapshot for which the device is mapped. parent Information identifying the pool, image, and snapshot id for the parent image in a layered rbd image (format 2 only).