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libnbd-release-notes-1.14 - Man Page

release notes for libnbd 1.14


These are the release notes for libnbd stable release 1.14. This describes the major changes since 1.12.

libnbd 1.14.0 was released on 1 August 2022.


No security issues were found in this release.

If you find a security issue, please read SECURITY in the source (online here: https://gitlab.com/nbdkit/libnbd/blob/master/SECURITY).  To find out about previous security issues in libnbd, see libnbd-security(3).

New APIs

No new APIs were added in this release.

Enhancements to existing APIs

Optimizations to nbd_pread_structured(3) (Eric Blake).

Many performance enhancements in the Python bindings: nbd.pread now avoids an extra memory allocation and copy.  Buffers can now be passed to nbd.Buffer.from_bytearray.  New methods nbd.Buffer.{to,from}_buffer allow control over copying and sharing nbd.Buffer.  Any buffer-like object can be used in nbd.aio_{pread,pwrite}.  len(nbd.Buffer(n)) now works.  Improve error messages when the wrong types are passed to several APIs.  Fix usage of PyGILState.  (Eric Blake)

Golang AioBuffer now calls panic on invalid usage (Nir Soffer).

In golang tests, use GOTRACEBACK=crash so we get full core dumps on failures.

kTLS should now work (transparently) when available in the kernel and GnuTLS.  Use of kTLS will be indicated in debug output.  (Daiki Ueno, František Krenželok)


New nbddump(1) tool which can efficiently hexdump the contents of an NBD server.

nbdcopy(1) now obeys the NBD server minimum/preferred block size when copying, which should make it more efficient and avoids issues with some qemu-nbd configurations where the minimum block size must be obeyed for correct operation.


New tests for nbd+vsock:// URI support.

Other improvements and bug fixes

Fixed rare TLS deadlock when reading from slow servers, and support for clean shutdown when connecting to qemu-nbd over TLS (thanks Michael Ablassmeier).

The library now uses the GnuTLS flag GNUTLS_NO_SIGNAL (if available) which ensures that TLS connections should not cause the main program to exit with SIGPIPE in certain cases of server failure.  (Libnbd has long used MSG_NOSIGNAL on non-TLS connections which has a similar effect.)

Various enhancements to fuzzing were made, including support for AFL++ clang-LTO mode, ASAN, allowing seed test cases to be captured, and extended testing of APIs.

Tests were fixed so they should pass on RHEL 7 and FreeBSD.


No changes in this release.


ARRAY_SIZE macro added to simplify static array sizing (thanks Laszlo Ersek).

Various errors found by Coverity were fixed.

See Also



Eric Blake

Nir Soffer

Richard W.M. Jones


This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

Referenced By


2024-06-25 libnbd-1.21.1