nbdkit-noextents-filter(1)

📦
version 1.48.1 · 14 versions
, in fedora 44

🌸 NAME 🌸

nbdkit-noextents-filter — disable extents in the underlying plugin 💅

okay so this is a page from the NBDKIT manual, section 1 (that's the "user commands" section bestie, we love a section 1 moment). It's about a lil filter called nbdkit-noextents-filter, and its whole job is turning extents OFF. That's it. That's the girl. 🎀

✨ SYNOPSIS ✨

nbdkit --filter=noextents plugin

🦋 DESCRIPTION 🦋

So first, vibe check: what even are "extents"? 💭 Extents are a feature of the NBD protocol / nbdkit that let the client spot sparse regions of the underlying disk. Like, "hey bestie, this chunk is just empty, don't stress about it". Sparse-awareness. Very efficient. Very demure.

nbdkit-noextents-filter disables that 🚫✨ so the plugin shows up as fully allocated — at least as far as a client that requests structured replies is concerned.

And yes, technically you could also use the --no-meta-contexts or --no-sr options to nbdkit to stop the client from negotiating extents at all — but no cap, that route comes with more side effects than this filter does. So if you just want the one thing, take the filter, okay? 🫶

When is this actually useful tho? Iconic combo alert 🚨: pair it with nbdkit-file-plugin(1) when you're serving a file off a file system that's known to have poor lseek(2) performance. And heads up, "tmpfs" is known to be one such system. She's fast at everything except this, apparently 😭

💖 PARAMETERS 💖

There are no parameters specific to nbdkit-noextents-filter. Nope, zero, nada, she's low maintenance 💅

Any parameters you do pass get handed straight through to — and processed by — the underlying plugin in the normal way. So whatever that plugin wants, that's what it gets. periodt.

🎀 FILES 🎀

  • $filterdir/nbdkit-noextents-filter.so — the filter itself 🧚

Wanna know where $filterdir even lives? Run nbdkit --dump-config and it'll tell you, easy peasy. 🔍

⭐ VERSION ⭐

"nbdkit-noextents-filter" first appeared in nbdkit 1.14. Baby's been around a minute. 👑

🌈 SEE ALSO 🌈

The whole friend group, fr fr:

👑 AUTHORS 👑

Richard W.M. Jones — the icon, the legend, the main character who wrote this 💜

Copyright Red Hat

🧾 LICENSE 🧾

bestie this is the legal bit, so I'm gonna say it exactly how it is — no paraphrasing, no cutting corners, iykyk. Read it, it matters. 💀

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.

okay that's the whole page bestie, you ate it 💅✨

this was nbdkit-1.48.1, dated 2026-08-29, and it's the nbdkit-noextents-filter(1) page — go forth and disable some extents, no cap 🦋🎀💖

📦 where this page comes from