nbdkit-nozero-filter - nbdkit nozero filter
nbdkit --filter=nozero plugin [zeromode=MODE] [plugin-args...]
nbdkit-nozero-filter is a filter that intentionally disables efficient handling of sparse file holes (ranges of all-zero bytes) across the NBD protocol. It is mainly useful for evaluating timing differences between naive vs. sparse-aware connections, and for testing client or server fallbacks.
Optional, controls which mode the filter will use. Mode none (default) means that zero support is not advertised to the client; mode emulate means that zero support is emulated by the filter using the plugin's
pwritecallback, regardless of whether the plugin itself implemented the
zerocallback with a more efficient way to write zeros.
Serve the file disk.img, but force the client to write zeroes explicitly rather than with
nbdkit --filter=nozero file disk.img
Serve the file disk.img, allowing the client to take advantage of less network traffic via
NBD_CMD_WRITE_ZEROES, but still forcing the data to be written explicitly rather than punching any holes:
nbdkit --filter=nozero file zeromode=emulate disk.img
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