BlockDeviceConfig

Block Device Configuration

Controls for block device configuration

There are a variety of independent attributes that it is desirable to control when configuring block devices for a virtual machine in OpenStack

Source type

• Glance image
• Cinder volume
• Ephemeral file

Guest format

• ext4 (or other FS formats)
• ISO
• Swap (different format per guest OS)
• None

Device type

• Disk
• CDROM
• Floppy
• Flash (MMC)

Disk bus

• USB
• IDE
• VirtIO
• SCSI

Shutdown action

• Delete
• Preserve

Command line syntax for block config

The 'nova boot' command currently uses a combination of the '-image' and '-block-device-mapping' command line args to configure storage. The latter is mostly a clone of the same named arg from the EC2 commands, and is not a very well designed syntax from the POV of extensibility.

Given the extra features to be supported, it is desirable to introduce a new syntax for 'nova boot' and friends which is more expressive

Key off the device type:

• -cdrom type=glance,id=XXXXXXXXX,bus=ide
• -disk type=cinder,id=XXXXXXXXX,bus=ide
• -mmc type=ephemeral,format=swap,size=50,dev=/dev/sda

Or a totally generic arg:

• -block type=glance,id=XXXXXXX
• -block type=cinder,id=XXXXXXX,bus=ide,device=cdrom
• -block type=ephemeral,format=swap,size=50,bus=ide,device=floppy