nbdkit-streaming-plugin man page
nbdkit-streaming-plugin — nbdkit streaming plugin
nbdkit streaming pipe=FILENAME [size=SIZE]
"nbdkit-streaming-plugin" is a plugin for nbdkit(1) that can turn certain kinds of input into a stream.
If the NBD client opens the NBD port, and writes from the start to the end of the disk without seeking backwards, then this plugin will turn the resulting disk image into a stream of data which is written to the named
Typical usage is with qemu tools. For example:
qemu-img convert input -O raw output
does not work if
"output" is a pipe. However this does:
nbdkit -U /tmp/nbd.sock streaming pipe=output --run ' qemu-img convert -n input -O raw $nbd '
Write to the named pipe or socket. If the pipe or socket does not exist, then it is created (as a named FIFO), otherwise the existing pipe or socket is opened and used.
This parameter is required.
Specify the virtual size of the stream.
This parameter is optional. If not specified, then the virtual disk appears to the client to be very large (effectively infinite). Whether you need to specify this parameter depends on the client. Some clients don't check the size and just write/stream, others do checks or calculations based on the apparent size.
Richard W.M. Jones
Copyright (C) 2014 Red Hat Inc.
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