NAME
nbdkit-noextents-filter - disable extents in the underlying plugin
SYNOPSIS
nbdkit --filter=noextents plugin
DESCRIPTION
“Extents” are a feature of the NBD protocol / nbdkit which allow the client to detect sparse regions of the underlying disk. "nbdkit-noextents-filter" disables this so that the plugin appears to be fully allocated, at least to a client that requests structured replies. It is also possible to use the --no-meta-contexts or --no-sr options to nbdkit to prevent the client from negotiating extents at all, but that is accompanied by more side effects than this filter.
This filter can be useful when combined with nbdkit-file-plugin(1) serving a file from a file system known to have poor lseek(2) performance ("tmpfs" is known to be one such system).
PARAMETERS
There are no parameters specific to nbdkit-noextents-filter. Any parameters are passed through to and processed by the underlying plugin in the normal way.
FILES
$filterdir/nbdkit-noextents-filter.so
The filter.
Use "nbdkit --dump-config" to find the location of $filterdir.
VERSION
"nbdkit-noextents-filter" first appeared in nbdkit 1.14.
SEE ALSO
nbdkit(1), nbdkit-filter(3), nbdkit-extentlist-filter(1), nbdkit-fua-filter(1), nbdkit-multi-conn-filter(1), nbdkit-nocache-filter(1), nbdkit-noparallel-filter(1), nbdkit-nozero-filter(1), nbdkit-file-plugin(1).
AUTHORS
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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