NAME
nbdkit-offset-filter - nbdkit offset filter
SYNOPSIS
nbdkit --filter=offset plugin offset=OFFSET range=LENGTH [plugin-args...]
DESCRIPTION
"nbdkit-offset-filter" is a filter that limits requests to the byte range "[offset .. offset+range-1]" within another plugin.
PARAMETERS
offset=OFFSET
The start offset. The offset must be ≥ 0.
This parameter is optional. If not given then "offset=0" is assumed.
range=LENGTH
The length of data to serve.
This parameter is optional. If not given then the range is served starting from the offset through to the end of the underlying file/device.
Note it is an error if the offset and/or range specify data which lies beyond the end of the underlying device. Use nbdkit-truncate-filter(1) to truncate or extend the size of plugins.
EXAMPLES
Serve part
of a file
Using nbdkit-file-plugin(1), serve the file
"disk.img" starting at offset "1M". The
total length served is "100M" (the underlying file
must therefore be at least "101M" in length):
nbdkit --filter=offset file disk.img offset=1M range=100M
Serve a
single partition
An easier way to do this is with
nbdkit-partition-filter(1).
One way to serve a single partition from a disk is to find the start and length of the partition, eg using:
$ parted
disk.img -- unit b print
...
Number Start End Size Type File system Flags
1 65536B 104792575B 104727040B primary ext2
You can then serve the partition only using:
nbdkit --filter=offset file disk.img offset=65536 range=104727040
FILES
$filterdir/nbdkit-offset-filter.so
The filter.
Use "nbdkit --dump-config" to find the location of $filterdir.
VERSION
"nbdkit-offset-filter" first appeared in nbdkit 1.2.
SEE ALSO
nbdkit(1), nbdkit-file-plugin(1), nbdkit-filter(3), nbdkit-partition-filter(1), nbdkit-protect-filter(1), nbdkit-tar-filter(1), nbdkit-truncate-filter(1).
AUTHORS
Eric Blake
Richard W.M. Jones
COPYRIGHT
Copyright Red Hat
LICENSE
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
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