nbdkit-pattern-plugin1

Usage

Overview

"nbdkit-pattern-plugin" is a plugin for nbdkit(1) which serves a fixed pattern of data, read only. This is used for testing nbdkit filters and NBD clients. To create test disks filled with other repeated patterns use nbdkit-data-plugin(1) or nbdkit-ones-plugin(1) instead.

The fixed pattern is the offset, as a 64 bit big endian integer, every 8 bytes. In hexadecimal this looks like:

 offset                         data
  0000:   00 00 00 00 00 00 00 00   00 00 00 00 00 00 00 08
  0010:   00 00 00 00 00 00 00 10   00 00 00 00 00 00 00 18
  0020:   00 00 00 00 00 00 00 20   00 00 00 00 00 00 00 28
                                  ↗ └──────────┬──────────┘
              byte at offset 0x28              │
                                               │
                                     64 bit big endian int
                                     encoding offset 0x28

The size of the virtual disk must be specified using the "size" parameter. If the size is not a multiple of 8 then the last 8 byte offset in the pattern is truncated.

 nbdkit pattern 9223372036854775807

 nbdkit pattern 1G --filter=swab swab-bits=64

Parameters

[size=]SIZE

Specify the virtual size of the disk image.

This parameter is required.

"size=" prefix may be omitted in most cases. See "Magic parameters" in nbdkit(1).

Files

$plugindir/nbdkit-pattern-plugin.so

The plugin.

Use "nbdkit --dump-config" to find the location of $plugindir.

Version

"nbdkit-pattern-plugin" first appeared in nbdkit 1.6.