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nbdkit(1) NBDKIT nbdkit(1) NAME nbdkit - network block device (NBD) server SYNOPSIS nbdkit [-4|--ipv4-only] [-6|--ipv6-only] [-D|--debug PLUGIN|FILTER|nbdkit.FLAG=N] [--exit-with-parent] [-e|--exportname EXPORTNAME] [--filter=FILTER ...] [-f|--foreground] [-g|--group GROUP] [-i|--ipaddr IPADDR] [--keepalive] [--log=default|stderr|syslog|null|/path] [--mask-handshake=MASK] [--name=NAME] [-n|--newstyle] [--no-mc|--no-meta-contexts] [--no-sr|--no-structured-replies] [-o|--oldstyle] [-P|--pidfile PIDFILE] [-p|--port PORT] [--print-uri] [-r|--readonly] [--run 'COMMAND ARGS ...'] [--selinux-label=LABEL] [-s|--single] [--swap] [-t|--threads THREADS] [--timeout=TIMEOUT] [--tls=off|on|require] [--tls-certificates=/path/to/certificates] [--tls-priority=PRIORITY] [--tls-psk=/path/to/pskfile] [--tls-verify-peer] [-U|--unix SOCKET|-] [-u|--user USER] [-v|--verbose] [--vsock] PLUGIN [[KEY=]VALUE [KEY=VALUE [...]]] | @PATH nbdkit --dump-config nbdkit PLUGIN --dump-plugin nbdkit --help nbdkit [-V|--version] nbdkit [--short-options|--long-options] DESCRIPTION Network Block Device (NBD) is a network protocol for accessing block devices over the network. Block devices are hard disks and things that behave like hard disks such as disk images and virtual machines. nbdkit is an NBD server, and also a powerful toolkit for creating your own NBD servers from unconventional sources. nbdkit ships with many plugins for performing common tasks like serving local files. Plugins and filters nbdkit is different from other NBD servers because you can easily create new Network Block Device sources by writing a few glue functions, possibly in C, or perhaps in a high level language like Perl or Python. The liberal licensing of nbdkit is meant to allow you to link nbdkit with proprietary libraries or to include nbdkit in proprietary code. If you want to write your own nbdkit plugin you should read nbdkit-plugin(3). nbdkit also has a concept of filters which can be layered on top of plugins. Several filters are provided with nbdkit and if you want to write your own you should read nbdkit-filter(3). EXAMPLES Basic file serving • Serve file disk.img on port 10809 using nbdkit-file-plugin(1), and connect to it using guestfish(1): nbdkit file disk.img guestfish --rw --format=raw -a nbd://localhost • Serve file disk.img on port 10809, requiring clients to use encrypted (TLS) connections: nbdkit --tls=require file disk.img Other nbdkit plugins • Create a small disk containing test patterns using nbdkit-data-plugin(1): nbdkit data ' ( 0x55 0xAA )*2048 ' • Forward an NBD connection to a remote server over HTTPS or SSH using nbdkit-curl-plugin(1) or nbdkit-ssh-plugin(1): nbdkit -r curl https://example.com/disk.img nbdkit ssh host=example.com /var/tmp/disk.img • Create a sparse 1 terabyte RAM disk using nbdkit-memory-plugin(1) and use it as a loop device (nbdkit-loop(1)): nbdkit memory 1T nbd-client localhost /dev/nbd0 • Create a floppy disk image containing files from a local directory using nbdkit-floppy-plugin(1): nbdkit floppy dir/ Combining plugins and filters • Serve only the first partition from compressed disk image disk.img.xz, combining nbdkit-partition-filter(1), nbdkit-xz-filter(1) and nbdkit-file-plugin(1). nbdkit --filter=partition --filter=xz file disk.img.xz partition=1 To understand this command line: plugin name and plugin parameter nbdkit --filter=partition --filter=xz file disk.img.xz partition=1 filters and filter parameter • Create a scratch, empty nbdkit device and inject errors and delays, for testing clients, using nbdkit-memory-plugin(1), nbdkit-error-filter(1) and nbdkit-delay-filter(1): nbdkit --filter=error --filter=delay memory 100M \ error-rate=10% rdelay=1 wdelay=1 Writing plugins in shell script • Write a simple, custom plugin in shell script using nbdkit-sh-plugin(3): nbdkit sh - <<'EOF' case "$1" in get_size) echo 1M ;; pread) dd if=/dev/zero count=$3 iflag=count_bytes ;; *) exit 2 ;; esac EOF • The same example as above can be written entirely on the command line using nbdkit-eval-plugin(1): nbdkit eval get_size='echo 1M' \ pread='dd if=/dev/zero count=$3 iflag=count_bytes' Display information Display information about nbdkit or a specific plugin: nbdkit --help nbdkit --version nbdkit --dump-config nbdkit example1 --help nbdkit example1 --dump-plugin NBD URIs and endpoints NBD has a way to specify the URI of an NBD endpoint to make it easy to interconnect NBD tools. Use the nbdkit --print-uri option to print the URI of this server instance. For example: $ nbdkit -U /tmp/socket --print-uri null nbd+unix://?socket=/tmp/socket Shell-quoted URI: "nbd+unix://?socket=/tmp/socket" Command to query the NBD endpoint: nbdinfo "nbd+unix://?socket=/tmp/socket" GLOBAL OPTIONS --help Display brief command line usage information and exit. -4 --ipv4-only -6 --ipv6-only When a non-numeric argument is passed to the -i option (such as a Fully Qualified Domain Name, or a host name from "/etc/hosts"), restrict the name resolution to IPv4 or IPv6 addresses. When the -i option is omitted, listen on only the IPv4 or IPv6 address of all interfaces (0.0.0.0 or "::", respectively). When both -4 and -6 options are present on the command line, the last one takes effect. -D PLUGIN.FLAG=N -D FILTER.FLAG=N --debug PLUGIN.FLAG=N --debug FILTER.FLAG=N Set the plugin or filter Debug Flag called "FLAG" to the integer value "N". See "Debug Flags" in nbdkit-plugin(3). -D nbdkit.FLAG=N --debug nbdkit.FLAG=N (nbdkit 1.18) Set the nbdkit server Debug Flag called "FLAG" to the integer value "N". See "SERVER DEBUG FLAGS" below. --dump-config Dump out the compile-time configuration values and exit. See nbdkit-probing(1). --dump-plugin Dump out information about the plugin and exit. See nbdkit-probing(1). --exit-with-parent If the parent process exits, we exit. This can be used to avoid complicated cleanup or orphaned nbdkit processes. There are some important caveats with this, see "EXIT WITH PARENT" in nbdkit-captive(1). An alternative to this is "CAPTIVE NBDKIT" in nbdkit-captive(1). This option implies --foreground. -e EXPORTNAME --export=EXPORTNAME --export-name=EXPORTNAME --exportname=EXPORTNAME Set a preferred exportname to expose in the shell environment created during --run. The use of this option without --run has no effect. This option does not change what nbdkit advertises as a server, but can aid in writing a captive client that wants to access particular content from a plugin that differentiates content based on the client's choice of export name. If not set, the --run environment is set to access the default exportname "" (empty string). --filter=FILTER Add a filter before the plugin. This option may be given one or more times to stack filters in front of the plugin. They are processed in the order they appear on the command line. See "FILTERS" and nbdkit-filter(3). -f --foreground --no-fork Don't fork into the background. -g GROUP --group=GROUP Change group to "GROUP" after starting up. A group name or numeric group ID can be used. The server needs sufficient permissions to be able to do this. Normally this would mean starting the server up as root. See also -u. -i IPADDR --ip-addr=IPADDR --ipaddr=IPADDR Listen on the specified interface. The default is to listen on all interfaces. See also -4, -6, and -p. --keep-alive --keepalive Enable TCP keepalive ("SO_KEEPALIVE") on TCP sockets. This can allow clients that reboot to be detected earlier. You may also have to adjust kernel parameters. For Linux see: https://tldp.org/HOWTO/TCP-Keepalive-HOWTO/usingkeepalive.html Only has an effect if nbdkit uses a TCP socket (so not for -U, -s, etc.) --log=stderr --log=syslog --log=null --log=/path --log=default Send error messages to standard error (--log=stderr), or to the system log (--log=syslog), discard them completely (--log=null, not recommended for normal use), or append them to a file (which must be an absolute path). The default (if --log is not used, or if you use --log=default) is: send error messages to stderr, unless nbdkit forks into the background in which case they are sent to syslog. These messages can be generated from plugins by calling nbdkit_error(3) or nbdkit_verror(3). Debug messages (-v/--verbose) always go to standard error and are never sent to the system log. --long-options List the long command line options (those starting with --) supported by this build of nbdkit. The options are listed one per line, and then nbdkit exits. This is used mainly to implement tab completion. See also --short-options. --mask-handshake=MASK This option can be used to mask off particular global features which are advertised during new-style handshake (defaulting to all supported bits set). See nbdkit-protocol(1). --name=NAME Name this nbdkit instance. This allows you to associate names with nbdkit processes, if you have several. The name appears in error and debug messages, but is otherwise unused by nbdkit. The name can be any string, but usually a short string containing only letters, numbers and common punctuation is best. -n --new-style --newstyle Use the newstyle NBD protocol. This is the default in nbdkit 1.3. In earlier versions the default was oldstyle. See nbdkit-protocol(1). --no-mc --no-meta-contexts Do not advertise meta contexts. Normally, nbdkit handles all client requests for arbitrary meta context names, with the response being affirmative for only the "base:allocation" meta context (nbdkit synthesizes this context even when the plugin does not support extents), so that clients can use the block status command. However, meta contexts are not a mandatory part of the newstyle NBD protocol, so this option can be used to debug client fallbacks for dealing with older servers that lack meta context support. See nbdkit-protocol(1). --no-sr --no-structured-replies Do not advertise structured replies. A client must request structured replies to take advantage of block status and potential sparse reads; however, as structured reads are not a mandatory part of the newstyle NBD protocol, this option can be used to debug client fallbacks for dealing with older servers. See nbdkit-protocol(1). -o --old-style --oldstyle Use the oldstyle NBD protocol. This was the default in nbdkit 1.2, but now the default is newstyle. Note this is incompatible with newer features such as export names and TLS. See nbdkit-protocol(1). -P PIDFILE --pid-file=PIDFILE --pidfile=PIDFILE Write "PIDFILE" (containing the process ID of the server) after nbdkit becomes ready to accept connections. If the file already exists, it is overwritten. nbdkit does not delete the file when it exits. -p PORT --port=PORT Change the TCP/IP port number on which nbdkit serves requests. The default is 10809. See also -i. --print-uri Print the URI. See "NBD URIs and endpoints" above. -r --read-only --readonly The export will be read-only. If a client writes, then it will get an error. Note that some plugins inherently don't support writes. With those plugins the -r option is added implicitly. nbdkit-cow-filter(1) can be placed over read-only plugins to provide copy-on-write (or "snapshot") functionality. If you are using qemu as a client then it also supports snapshots. nbdkit-readonly-filter(1) or nbdkit-protect-filter(1) can selectively add write-protection. --run 'COMMAND ARGS ...' Run nbdkit as a captive subprocess of the command. When the command exits, nbdkit is killed. See "CAPTIVE NBDKIT" in nbdkit-captive(1). Note that the command is executed by /bin/sh. On some platforms like Debian this might not be a full-featured shell. This option implies --foreground. In nbdkit 1.34 you normally had to add -U -, otherwise nbdkit would use a TCP/IP port which was not what you wanted. In nbdkit 1.36, using --run implies -U -. If you want the old behaviour of nbdkit then you must use the --port option explicitly. --selinux-label=SOCKET-LABEL Apply the SELinux label "SOCKET-LABEL" to the nbdkit listening socket. The common perhaps only use of this option is to allow libvirt guests which are using SELinux and sVirt confinement to access nbdkit Unix domain sockets. The example below shows how to do this. Note that the socket and filesystem labels are different. nbdkit -U /tmp/sock --selinux-label=system_u:object_r:svirt_socket_t:s0 ... chcon system_u:object_r:svirt_image_t:s0 /tmp/sock --short-options List the short command line options (single letter options starting with -) supported by this build of nbdkit. The options are listed one per line, and then nbdkit exits. This is used mainly to implement tab completion. See also --long-options. -s --single --stdin Don't fork. Handle a single NBD connection on stdin/stdout. After stdin closes, the server exits. You can use this option to run nbdkit from inetd or similar superservers; or just for testing; or if you want to run nbdkit in a non-conventional way. Note that if you want to run nbdkit from systemd, then it may be better to use "SOCKET ACTIVATION" in nbdkit-service(1) instead of this option. This option implies --foreground. --swap (nbdkit 1.18) Specifies that the NBD device will be used as swap space loop mounted on the same machine which is running nbdkit. To avoid deadlocks this locks the whole nbdkit process into memory using mlockall(2). This may require additional permissions, such as starting the server as root or raising the "RLIMIT_MEMLOCK" (ulimit(1) -l) limit on the process. -t THREADS --threads=THREADS Set the number of threads to be used per connection, which in turn controls the number of outstanding requests that can be processed at once. Only matters for plugins with thread_model=parallel (where it defaults to 16). To force serialized behavior (useful if the client is not prepared for out-of-order responses), set this to 1. --timeout=TIMEOUT (nbdkit 1.42, not Windows) If the client does not negotiate a full NBD session within "TIMEOUT" seconds, then drop the connection. This can be used as an additional security measure to ensure that clients don't consume resources by opening lots of connections and then not negotiating (or negotiating slowly) the full NBD session. It is particularly useful in conjunction with TLS client authentication (see nbdkit-tls(1)). The timeout is measured from the point of the initial TCP connection to the point where NBD session negotiation ends (including TLS, if used). If the timeout is exceeded during this negotiation, the connection is dropped. Setting this too low will cause problems for clients listing lots of exports. The default is no timeout. "TIMEOUT" can be any format supported by nbdkit_parse_delay(3). --tls=off --tls=on --tls=require Disable, enable or require TLS (authentication and encryption support). See nbdkit-tls(1). --tls-certificates=/path/to/certificates Set the path to the TLS certificates directory. If not specified, some built-in paths are checked. See nbdkit-tls(1) for more details. --tls-priority=PRIORITY Override the TLS priority string. The TLS priority controls which ciphers, key exchange methods and MACs are used and in what order. See "Priority strings" in the GnuTLS manual The default may be set when nbdkit is built (and if not set, defaults to "NORMAL"). --tls-psk=/path/to/pskfile Set the path to the pre-shared keys (PSK) file. If used, this overrides certificate authentication. There is no built-in path. See nbdkit-tls(1) for more details. --tls-verify-peer Enables TLS client certificate verification. The default is not to check the client's certificate. -U SOCKET --unix=SOCKET -U - --unix - Accept connections on the Unix domain socket "SOCKET" (which is a path). nbdkit creates this socket, but it will probably have incorrect permissions (too permissive). If it is a problem that some unauthorized user could connect to this socket between the time that nbdkit starts up and the authorized user connects, then put the socket into a directory that has restrictive permissions. nbdkit does not delete the socket file when it exits. The caller should delete the socket file after use (else if you try to start nbdkit up again you will get an "Address already in use" error). If the socket name is - then nbdkit generates a randomly named private socket. This is implied by the --run option. See also "CAPTIVE NBDKIT" in nbdkit-captive(1). -u USER --user=USER Change user to "USER" after starting up. A user name or numeric user ID can be used. The server needs sufficient permissions to be able to do this. Normally this would mean starting the server up as root. See also -g. -v --verbose Enable verbose messages. It's a good idea to use -f as well so the process does not fork into the background. The messages are sent to stderr. Note they are not affected by the --log option (which is only for error messages). These messages can be generated from plugins by calling nbdkit_debug(3) or nbdkit_vdebug(3). -V --version Print the version number of nbdkit and exit. The --dump-config option provides separate major and minor numbers and may be easier to parse from shell scripts. --vsock (nbdkit 1.16) Use the AF_VSOCK protocol (instead of TCP/IP). You must use this in conjunction with -p/--port. See "AF_VSOCK" in nbdkit-service(1). PLUGIN NAME You can give the full path to the plugin, like this: nbdkit $libdir/nbdkit/plugins/nbdkit-file-plugin.so [...] but it is usually more convenient to use this equivalent syntax: nbdkit file [...] $libdir is set at compile time. To print it out, do: nbdkit --dump-config PLUGIN CONFIGURATION After specifying the plugin name you can (optionally, it depends on the plugin) give plugin configuration on the command line in the form of "key=value". For example: nbdkit file file=disk.img To list all the options supported by a plugin, do: nbdkit --help file To dump information about a plugin, do: nbdkit file --dump-plugin Magic parameters Some plugins declare a special "magic config key". This is a key which is assumed if no "key=" part is present. For example: nbdkit file disk.img is assumed to be "file=disk.img" because the file plugin declares "file" as its magic config key. There can be ambiguity in the parsing of magic config keys if the value might look like a "key=value". If there could be ambiguity then modify the value, eg. by prefixing it with "./" There is also a special exception for plugins which do not declare a magic config key, but where the first plugin argument does not contain an '=' character: it is assumed to be "script=value". This is used by scripting language plugins: nbdkit perl foo.pl [args...] has the same meaning as: nbdkit perl script=foo.pl [args...] @PATH If you need to pass a large number of key=value parameters, you can place them in an external file, for example: $ cat partitions.txt # The list of partitions to load: file=partition1.img file=partition2.img file=partition3.img $ nbdkit partitioning @./partitions.txt The pathname after the "@" must contain at least one "/" character (this is to avoid compatibility problems with some existing plugins), so if the file is the current directory as in the example above, use "@./filename" There must be one parameter per line. Lines beginning with "#" and blank lines are ignored. This only works for "key=value" plugin & filter parameters (not for the plugin name or --options). You can use multiple @PATH parameters. You or use @PATH recursively in another @PATH file. The path in that case is taken relative to the containing file. Shebang scripts You can use "#!" to run nbdkit plugins written in most scripting languages. The file should be executable. For example: #!/usr/sbin/nbdkit perl sub open { # etc } (see nbdkit-perl-plugin(3) for a full example). SERVER DEBUG FLAGS As well as enabling or disabling debugging in the server using --verbose you can control extra debugging in the server using the -D nbdkit.* flags listed in this section. Note these flags are an internal implementation detail of the server and may be changed or removed at any time in the future. -D nbdkit.backend.controlpath=0 -D nbdkit.backend.controlpath=1 -D nbdkit.backend.datapath=0 -D nbdkit.backend.datapath=1 These flags control the verbosity of nbdkit backend debugging messages (the ones which show every request processed by the server). The default for both settings is 1 (normal debugging) but you can set them to 0 to suppress these messages. -D nbdkit.backend.datapath=0 is the more useful setting which lets you suppress messages about pread, pwrite, zero, trim, etc. commands. When transferring large amounts of data these messages are numerous and not usually very interesting. -D nbdkit.backend.controlpath=0 suppresses the non-datapath commands (config, open, close, can_write, etc.) -D nbdkit.environ=1 Print nbdkit's environment variables in the debug output at start up. This is insecure because environment variables may contain both sensitive and user-controlled information, so it should not be used routinely. But it is useful for tracking down problems related to environment variables. -D nbdkit.tls.log=N Enable TLS logging. "N" can be in the range 0 (no logging) to 99. See gnutls_global_set_log_level(3). -D nbdkit.tls.session=1 Print additional information about the TLS session, such as the type of authentication and encryption, and client certificate information. SIGNALS nbdkit responds to the following signals: "SIGINT" "SIGQUIT" "SIGTERM" The server exits cleanly. "SIGPIPE" This signal is ignored. ENVIRONMENT VARIABLES "LISTEN_FDS" "LISTEN_PID" If present in the environment when nbdkit starts up, these trigger "SOCKET ACTIVATION" in nbdkit-service(1). SEE ALSO Other topics nbdkit-captive(1) Run nbdkit under another process and have it reliably cleaned up. nbdkit-client(1) How to mount NBD filesystems on a client machine. nbdkit-loop(1) Use nbdkit with the Linux kernel client to create loop devices and loop mounts. nbdkit-probing(1) How to probe for nbdkit configuration and plugins. nbdkit-protocol(1) Which parts of the NBD protocol nbdkit supports. nbdkit-security(1) Lists past security issues in nbdkit. nbdkit-service(1) Running nbdkit as a service, and systemd socket activation. nbdkit-tls(1) Authentication and encryption of NBD connections (sometimes incorrectly called "SSL"). nbdkit-tracing(3) Adding user statically defined tracing (USDT) probes to nbdkit. Plugins nbdkit-blkio-plugin(1), nbdkit-cdi-plugin(1), nbdkit-curl-plugin(1), nbdkit-data-plugin(1), nbdkit-eval-plugin(1), nbdkit-example1-plugin(1), nbdkit-example2-plugin(1), nbdkit-example3-plugin(1), nbdkit-example4-plugin(1), nbdkit-file-plugin(1), nbdkit-floppy-plugin(1), nbdkit-full-plugin(1), nbdkit-gcs-plugin(1), nbdkit-guestfs-plugin(1), nbdkit-info-plugin(1), nbdkit-iso-plugin(1), nbdkit-libvirt-plugin(1), nbdkit-linuxdisk-plugin(1), nbdkit-memory-plugin(1), nbdkit-nbd-plugin(1), nbdkit-nfs-plugin(1), nbdkit-null-plugin(1), nbdkit-ondemand-plugin(1), nbdkit-ones-plugin(1), nbdkit-partitioning-plugin(1), nbdkit-pattern-plugin(1), nbdkit-random-plugin(1), nbdkit-S3-plugin(1), nbdkit-sparse-random-plugin(1), nbdkit-split-plugin(1), nbdkit-ssh-plugin(1), nbdkit-tmpdisk-plugin(1), nbdkit-torrent-plugin(1), nbdkit-vddk-plugin(1), nbdkit-vram-plugin(1), nbdkit-zero-plugin(1) ; nbdkit-cc-plugin(3), nbdkit-golang-plugin(3), nbdkit-lua-plugin(3), nbdkit-ocaml-plugin(3), nbdkit-perl-plugin(3), nbdkit-python-plugin(3), nbdkit-rust-plugin(3), nbdkit-sh-plugin(3), nbdkit-tcl-plugin(3) . Filters nbdkit-blocksize-filter(1), nbdkit-blocksize-policy-filter(1), nbdkit-bzip2-filter(1), nbdkit-cache-filter(1), nbdkit-checkwrite-filter(1), nbdkit-count-filter(1), nbdkit-cow-filter(1), nbdkit-ddrescue-filter(1), nbdkit-delay-filter(1), nbdkit-error-filter(1), nbdkit-evil-filter(1), nbdkit-exitlast-filter(1), nbdkit-exitwhen-filter(1), nbdkit-exportname-filter(1), nbdkit-ext2-filter(1), nbdkit-extentlist-filter(1), nbdkit-fua-filter(1), nbdkit-gzip-filter(1), nbdkit-indexed-gzip-filter(1), nbdkit-ip-filter(1), nbdkit-limit-filter(1), nbdkit-log-filter(1), nbdkit-luks-filter(1), nbdkit-lzip-filter(1), nbdkit-map-filter(1), nbdkit-multi-conn-filter(1), nbdkit-nocache-filter(1), nbdkit-noextents-filter(1), nbdkit-nofilter-filter(1), nbdkit-noparallel-filter(1), nbdkit-nozero-filter(1), nbdkit-offset-filter(1), nbdkit-openonce-filter(1), nbdkit-partition-filter(1), nbdkit-pause-filter(1), nbdkit-protect-filter(1), nbdkit-qcow2dec-filter(1), nbdkit-rate-filter(1), nbdkit-readahead-filter(1), nbdkit-readonly-filter(1), nbdkit-retry-filter(1), nbdkit-retry-request-filter(1), nbdkit-rotational-filter(1), nbdkit-scan-filter(1), nbdkit-spinning-filter(1), nbdkit-stats-filter(1), nbdkit-swab-filter(1), nbdkit-tar-filter(1), nbdkit-time-limit-filter(1), nbdkit-tls-fallback-filter(1), nbdkit-truncate-filter(1), nbdkit-xz-filter(1) . For developers nbdkit-plugin(3), nbdkit-filter(3). Writing plugins in other programming languages nbdkit-cc-plugin(3), nbdkit-golang-plugin(3), nbdkit-lua-plugin(3), nbdkit-ocaml-plugin(3), nbdkit-perl-plugin(3), nbdkit-python-plugin(3), nbdkit-rust-plugin(3), nbdkit-sh-plugin(3), nbdkit-tcl-plugin(3) . Release notes for previous releases of nbdkit nbdkit-release-notes-1.46(1), nbdkit-release-notes-1.44(1), nbdkit-release-notes-1.42(1), nbdkit-release-notes-1.40(1), nbdkit-release-notes-1.38(1), nbdkit-release-notes-1.36(1), nbdkit-release-notes-1.34(1), nbdkit-release-notes-1.32(1), nbdkit-release-notes-1.30(1), nbdkit-release-notes-1.28(1), nbdkit-release-notes-1.26(1), nbdkit-release-notes-1.24(1), nbdkit-release-notes-1.22(1), nbdkit-release-notes-1.20(1), nbdkit-release-notes-1.18(1), nbdkit-release-notes-1.16(1), nbdkit-release-notes-1.14(1), nbdkit-release-notes-1.12(1), nbdkit-release-notes-1.10(1), nbdkit-release-notes-1.8(1), nbdkit-release-notes-1.6(1), nbdkit-release-notes-1.4(1). NBD clients guestfish(1), libnbd(3), nbd-client(1), nbdcopy(1), nbdfuse(1), nbdinfo(1), nbdsh(1), qemu(1). nbdkit links http://gitlab.com/nbdkit/nbdkit Source code. Other NBD servers qemu-nbd(1), nbd-server(1), https://github.com/bignaux/lwNBD, https://bitbucket.org/hirofuchi/xnbd. Documentation for the NBD protocol https://github.com/NetworkBlockDevice/nbd/blob/master/doc/proto.md, https://github.com/NetworkBlockDevice/nbd/blob/master/doc/uri.md, https://nbd.sourceforge.io/. Similar protocols https://en.wikipedia.org/wiki/iSCSI, https://en.wikipedia.org/wiki/ATA_over_Ethernet, https://en.wikipedia.org/wiki/Fibre_Channel_over_Ethernet. Other manual pages of interest gnutls_priority_init(3), qemu-img(1), psktool(1), systemd.socket(5). AUTHORS Eric Blake Laszlo Ersek Richard W.M. Jones Yann E. MORIN Nikolaus Rath Franois Revol Nir Soffer Alan Somers Pino Toscano 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: • Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. • Redistributions in binary form must reproduce the above copyright notice, this list of 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. THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. nbdkit-1.46.0 2026-03-04 nbdkit(1)
NAME | SYNOPSIS | DESCRIPTION | EXAMPLES | GLOBAL OPTIONS | PLUGIN NAME | PLUGIN CONFIGURATION | SERVER DEBUG FLAGS | SIGNALS | ENVIRONMENT VARIABLES | SEE ALSO | AUTHORS | COPYRIGHT | LICENSE
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