I'm pleased to announce the release of nbdkit 1.46. nbdkit is a Network Block Device server. You can read more about Network Block Device and nbdkit here: https://libguestfs.org/nbdkit.1.html The new version is available here: https://download.libguestfs.org/nbdkit/1.46-stable/ The release notes are attached below or you can read them online here: https://libguestfs.org/nbdkit-release-notes-1.46.1.html Rich. ---------------------------------------------------------------------- These are the release notes for nbdkit stable release 1.46. This describes the major changes since 1.44. nbdkit 1.46.0 was released on 20 December 2025. Security On certain types of storage, notably where a disk image is on an NFS mount, nbdkit would truncate zero requests to 64M. As nbdcopy(1) defaults to 128M block size, this could leave parts of a disk unzeroed, exposing older content. This was fixed in 1.44.1 and the fix was backported all the way back to the 1.38 branch. For more details see https://gitlab.com/nbdkit/nbdkit/-/commit/20b23fc9838faeddfd42664a7f497a9... (thanks Alex Kalenyuk). See nbdkit-security(1) for past security issues. Plugins New nbdkit-vram-plugin(1) which allows Video RAM to be turned into an NBD disk, using OpenCL. nbdkit-vddk-plugin(1) "export" parameter (added in 1.44) now allows exports from subdirectories on the ESXi server (thanks Ming Xie). nbdkit-data-plugin(1) now supports "base64:..." in format strings. nbdkit-sh-plugin(3) and nbdkit-extentlist-filter(1) both now allow blank lines and comments in the list of extents (Eric Blake). nbdkit-ssh-plugin(1) can now handle remote block devices properly (thanks trainzkid). Also we display information about the remote SSH server in debug output. nbdkit-random-plugin(1) has a new "fast=true" mode which trades increased performance for less randomness. nbdkit-pattern-plugin(1) has new "stride" and "upper" parameters. Stride is used for creating patterns that align to filesystem or device block boundaries. Upper is used to modify the upper bits of each pattern, so that a different pattern appears on each run. This plugin also now supports checking writes. nbdkit-file-plugin(1) prints more useful debugging (when the -v option is used). On Windows this plugin now displays complete error messages instead of just error codes. The existing "cache=none" parameter has been renamed "reduce-memory-pressure=true" to reflect what it actually does (but the old parameter can still be used). Filters nbdkit-cacheextents-filter was deprecated before and has been removed in this release of nbdkit. If you used this filter before, the advice is simply to remove it from the filter chain as it usually wasn't effective. New nbdkit-count-filter(1) which produces a simple summary of the number of bytes read, written, etc. New nbdkit-indexed-gzip-filter(1) which can be used to random access gzip files efficiently (Shasheen Ediriweera). New nbdkit-map-filter(1) which can remap disk blocks arbitrarily. nbdkit-delay-filter(1) has a new "delay-trigger=FILE" option that lets you enable the filter based on the existence of a file. Language bindings Python binding for nbdkit_parse_bool(3). Fix crasher when unloading OCaml plugins (Guillaume Munch-Maccagnoni). Also we document that "nbdkit -s" does not work for OCaml plugins, you must use systemd socket activation instead. Server New nbdkit --name parameter which allows you to name nbdkit instances. This is useful when you have multiple copies of nbdkit running, especially if they are all writing debug or error messages into a single log file, so you can tell which instance produced a particular message (thanks Ming Xie). You can now read nbdkit command line parameters from an external file using @PATH syntax. nbdkit --long-options and --short-options are used to implement bash completion. Previously they were hidden, implementation-specific options. However they are useful enough to support and document. During the negotiation phase we now allow the client to send more than one "OPT_LIST" request (Eric Blake). Post-Quantum Cryptography (PQC) is now fully supported (thanks Dan Berrange). New command line option --tls-priority allows you to temporarily override the system TLS priority string. API New nbdkit_debug_hexdump(3) function which can be used to print a buffer in canonical hexdump format, for debugging. Bug fixes nbdkit-file-plugin(1) trimming and zeroing paths were fixed so they should work on a wider range of backing storage. Empty string is now rejected as either a plugin or filter name. This caused us to try to dlopen("") which actually opens the current executable (apparently a glibc extension). It would fail with a very confusing error. Fix nbdkit_parse_delay(3) on i386 without SSE. The previous code used the wrong floating point rounding mode. The way that nbdkit-linuxdisk-plugin(1) parsed the output of du(1) using getline(3) was not POSIX compliant, and a change to glibc broke it. This was fixed in nbdkit, but also caused POSIX to reconsider the wording of the getline standard (thanks Eric Blake). Fix our use of mke2fs(8) when creating a test disk for nbdkit-ext2-filter(1). This greatly reduces the amount of disk space used for nbdkit builds (Mykola Ivanets). Fix crashing bugs in nbdkit-checkwrite-filter(1) (Eric Blake). Fix order of inclusion of Python header file because of changes in recent Python 3.14. nbdkit-readonly-filter(1) now advertises the correct readonly status down to plugins (Eric Blake). Review Coverity warnings. Documentation Document how to attach NBD devices to QEMU VMs, either when using qemu directly, or with libvirt (thanks Vadim Rozenfeld, Peter Krempa). TODO and SECURITY files in the git repository now use markdown. Tests Tests no longer fail if qemu-img(1) is not available at build time. Build Installed package names are printed by "./configure". Internals New ONCE() macro which runs code only once. This is used for some informational debug messages where we want the message to be printed once, the first time the situation is encountered. Several extensions to the internal vector type, including "vector_uniq", "vector_append_array", "vector_insert_array", "vector_remove_range". Fix the memory allocation behaviour of the internal vector library, which should reduce memory usage in some situations (Eric Blake). New tests functions "requires_tls", "requires_tls_certificates", "requires_tls_psk". Use "__attribute__((nonnull))" in more places, and add "__attribute__((malloc))" annotation on certain functions. SEE ALSO nbdkit(1). AUTHORS Authors of nbdkit 1.46: Eric Blake Michael Ablassmeier Mykola Ivanets Richard W.M. Jones Shasheen Ediriweera -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-p2v converts physical machines to virtual machines. Boot with a live CD or over the network (PXE) and turn machines into KVM guests. http://libguestfs.org/virt-v2v