NAME

       nbdkit-ext2-plugin - read and write files inside ext2, ext3 or ext4 filesystems

SYNOPSIS

        nbdkit ext2 disk=fs.img file=/disks/disk.raw

        nbdkit --filter=partition ext2 \
                                  disk=disk.img file=/disks/disk.raw \
                                  partition=1

DESCRIPTION

       "nbdkit-ext2-plugin" is an nbdkit plugin which can read and write files inside ext2, ext3
       or ext4 filesystem images.

       Suppose you have an ext2/3/4 filesystem image called fs.img which contains inside itself a
       file called disk.raw inside a directory on the filesystem called /disks, then you could
       serve that file over NBD using:

        nbdkit ext2 disk=fs.img file=/disks/disk.raw

       Commonly disk images are partitioned.  In that case you must use
       nbdkit-partition-filter(1) to select the partition:

        nbdkit --filter=partition ext2 disk=.. file=.. partition=1

       This plugin can both read and write to the file inside the filesystem.  Use the -r flag to
       force a readonly connection, but note this does not guarantee that no writes are made to
       the filesystem.  In particular we may have to replay the ext3 journal in order to open a
       filesystem even read-only.

       The plugin does not support multiple parallel connections, because there is a risk of
       corrupting the filesystem (as if the filesystem was mounted by multiple machines).  If a
       second connection is made to nbdkit, it will block until the first connection closes.

       The plugin is implemented using the ext2fs library which is provided in most Linux
       distros, and also available as part of the e2fsprogs project.

       nbdkit-guestfs-plugin(1) is a more generic plugin which can read files from all kinds of
       different filesystem types, even if they are partitioned or use logical volumes.  It uses
       libguestfs instead of e2fsprogs.

PARAMETERS

       disk=FILENAME
           The ext2, ext3 or ext4 filesystem, a file on the host.

           You could also use a device name here if the filesystem is located on a device.  Be
           careful that the filesystem is not being accessed in parallel by another program and
           is not mounted, as that will almost certainly result in disk corruption in the
           filesystem.

           The plugin expects a raw filesystem.  If the file/device is partitioned, use
           nbdkit-partition-filter(1).

       file=PATH
           The full path of the file within the filesystem that will be exposed over NBD.  The
           path must be absolute (starts with "/").

FILES

       $plugindir/nbdkit-ext2-plugin.so
           The plugin.

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

VERSION

       "nbdkit-ext2-plugin" first appeared in nbdkit 1.4.

SEE ALSO

       nbdkit(1), nbdkit-plugin(3), nbdkit-partition-filter(1), nbdkit-guestfs-plugin(1),
       http://e2fsprogs.sourceforge.net/, fuse2fs(1).

AUTHORS

       Richard W.M. Jones

COPYRIGHT

       Copyright (C) 2018 Red Hat Inc.

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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           conditions and the following disclaimer.

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           conditions and the following disclaimer in the documentation and/or other materials
           provided with the distribution.

       ·   Neither the name of Red Hat nor the names of its contributors may be used to endorse
           or promote products derived from this software without specific prior written
           permission.

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