# Nixos-install fails building hwdb.bin
**URL:** https://discourse.nixos.org/t/nixos-install-fails-building-hwdb-bin/69750
**Category:** Help
**Created:** [September 25, 2025, 1:53am UTC](https://discourse.nixos.org/t/nixos-install-fails-building-hwdb-bin/69750 "2025-09-25T01:53:51Z")
**Posts on this page:** 7
**Page:** 1
### Author:  [@zwol](https://discourse.nixos.org/u/zwol)
#### Post date: [September 25, 2025, 1:53am UTC](https://discourse.nixos.org/t/nixos-install-fails-building-hwdb-bin/69750/1 "2025-09-25T01:53:52Z")
```none
# nixos-install --flake 'git+https://git.sr.ht/~zackw/server-configs?dir=nix#tinka'
copying channel...
building the flake in git+https://git.sr.ht/~zackw/server-configs?dir=nix&ref=refs/heads/nix-and-guix&rev=74316117b86b4edc2259b3e51bd70060b260dc7a...
error: builder for '/nix/store/bnya0xz50m7kixgmmcw351b28djf63b4-hwdb.bin.drv' failed with exit code 1;
last 8 log lines:
> Adding hwdb files for package /nix/store/d84f8nm2na5cr53m4jk0qk2mj7lgr9fx-systemd-257.9
> Adding hwdb files for package /nix/store/f040c9mhj9sm2mngzqpbsx6walbpqqnr-ipv6-privacy-extensions.rules
> Adding hwdb files for package /nix/store/xgnd6bkasz0hb6817dg9jhjqifkd9jcd-ipv6-privacy-extensions.rules
> Adding hwdb files for package /nix/store/8lnq3lb6mv0xf8vazljmyk5ghra6qmwx-bcache-tools-1.0.8
> Adding hwdb files for package /nix/store/is5x55rsgcn5dw928b993vhanhd22mcq-extra-udev-rules
> Adding hwdb files for package /nix/store/cajxzhhk2xv3vvkklx2alik2zdh9kfrw-extra-hwdb-file
> Adding hwdb files for package /nix/store/mcwrmay5m4z0mbb3sd989jpx9j7rxllz-98-block-io-scheduler.rules
> Generating hwdb database...
For full logs, run:
nix log /nix/store/bnya0xz50m7kixgmmcw351b28djf63b4-hwdb.bin.drv
note: build failure may have been caused by lack of free disk space
error: 1 dependencies of derivation '/nix/store/9hhvmhi7zvwidyrqi0d6ahyvq95ghv5a-etc.drv' failed to build
error: 1 dependencies of derivation '/nix/store/yvld8yy5ksb4p6vjr8qpgr4ly0yj5qqz-nixos-system-tinka-25.05.20250923.d1d8831.drv' failed to build
```
It isn’t actually lack of disk space:
```none
# df -h
Filesystem Size Used Avail Use% Mounted on
devtmpfs 99M 0 99M 0% /dev
tmpfs 986M 0 986M 0% /dev/shm
tmpfs 493M 2.8M 491M 1% /run
tmpfs 986M 27M 960M 3% /
/dev/root 1.7G 1.7G 0 100% /iso
/dev/loop0 1.6G 1.6G 0 100% /nix/.ro-store
tmpfs 3.0G 4.2M 3.0G 1% /nix/.rw-store
overlay 3.0G 4.2M 3.0G 1% /nix/store
tmpfs 1.0M 0 1.0M 0% /run/credentials/systemd-journald.service
tmpfs 986M 1.2M 985M 1% /run/wrappers
tmpfs 1.0M 0 1.0M 0% /run/credentials/getty@tty1.service
tmpfs 1.0M 0 1.0M 0% /run/credentials/serial-getty@ttyS0.service
tmpfs 198M 4.0K 198M 1% /run/user/1000
none 1.0M 336K 688K 33% /mnt
/dev/vda1 254M 0 254M 0% /mnt/boot
/dev/vda3 766M 75M 692M 10% /mnt/nix/scratch
/dev/vda2 940K 52K 746K 7% /mnt/nix/state
tmpfs 198M 4.0K 198M 1% /run/user/0
/dev/vda5 8.0G 4.2G 3.9G 52% /mnt/nix/store
```
And `/mnt/nix/var/log/nix/drvs/bn/ya0xz50m7kixgmmcw351b28djf63b4-hwdb.bin.drv.bz2` contains no additional information. Looking at [the code to build this derivation](https://github.com/NixOS/nixpkgs/blob/d1d883129b193f0b495d75c148c2c3a7d95789a0/nixos/modules/services/hardware/udev.nix#L170-L191), it seems like an invocation of `systemd-hwdb` is failing _silently_. Then I ran the same sequence of commands by hand (as root, not in a chroot), and they all _succeeded_, including the `systemd-hwdb` call.
Can anyone suggest how I can get unstuck here?
---
### Author:  [@waffle8946](https://discourse.nixos.org/u/waffle8946)
#### Post date: [September 25, 2025, 1:02pm UTC](https://discourse.nixos.org/t/nixos-install-fails-building-hwdb-bin/69750/2 "2025-09-25T13:02:48Z")
Are you using btrfs anywhere at all?
Also 8 gigs seems shockingly small for the nix store. I’ve struggled with even using 40 gigs in the past and would recommend 100.
Also keep in mind, builds happen in `/tmp` which is on-disk, and it really looks like you are running out of space.
---
### Author:  [@zwol](https://discourse.nixos.org/u/zwol)
#### Post date: [September 25, 2025, 2:18pm UTC](https://discourse.nixos.org/t/nixos-install-fails-building-hwdb-bin/69750/3 "2025-09-25T14:18:25Z")
> [@waffle8946](#):
>
> Are you using btrfs anywhere at all?
No. Never have, probably never will.
> 8 gigs seems shockingly small for the nix store. I’ve struggled with even using 40 gigs in the past and would recommend 100.
This VPS only _has_ 24 gigs of storage and I would like to use as much of that as possible for _data_, thank you.
Local test images indicated only about 2G would be needed for the store, but somehow the space requirement more than doubled when I moved it to the real installation. I plan to tinker a little and see if I can claw back some of the space once I have a working install.
> builds happen in `/tmp` which is on-disk
You wouldn’t happen to know _which_ `/tmp` that is, would you? There’s at least three possibilities.
---
### Author:  [@bme](https://discourse.nixos.org/u/bme)
#### Post date: [September 25, 2025, 2:29pm UTC](https://discourse.nixos.org/t/nixos-install-fails-building-hwdb-bin/69750/4 "2025-09-25T14:29:52Z")
> [@zwol](#):
>
> This VPS only _has_ 24 gigs of storage and I would like to use as much of that as possible for _data_, thank you.
If you are running very little you can fit your store into ~ 5G, but this is really a how long is a piece of string question. The stuff I am doing is basically running observability (opentelemetry) + discovery (consul) + one service. We (work) also retain no generations, and do a prebake on a larger machine so that 99% of the build is already done with as much pruned as possible s.t. rebuilds are pulling in small delta. It’s possible that if you can get your build done at all you can prune the store quite aggressively back down. Depends on what the live set of roots is.
> [@zwol](#):
>
> You wouldn’t happen to know _which_ `/tmp` that is, would you? There’s at least three possibilities.
`/tmp` is by definition mounted at only one spot (outside of namespaces / chroots), and that’s what is being referenced.
---
### Author:  [@zwol](https://discourse.nixos.org/u/zwol)
#### Post date: [September 25, 2025, 2:58pm UTC](https://discourse.nixos.org/t/nixos-install-fails-building-hwdb-bin/69750/5 "2025-09-25T14:58:57Z")
> [@bme](#):
>
> > [@zwol](#):
> >
> > You wouldn’t happen to know _which_ `/tmp` that is, would you? There’s at least three possibilities.
>
> `/tmp` is by definition mounted at only one spot (outside of namespaces / chroots)
That’s just it - this is all running from within the installer CD, so there’s at least two namespaces involved, the installer’s environment and the environment being constructed, plus builder processes get sandboxed so they _could_ have their own `/tmp`
To put it another way, the directory that appears as `/tmp` _to a builder process_, _being run from within the installer_, could be `/tmp`, or `/mnt/tmp`, or some third path I don’t know about, from the perspective of the installation shell.
---
### Author:  [@bme](https://discourse.nixos.org/u/bme)
#### Post date: [September 25, 2025, 3:47pm UTC](https://discourse.nixos.org/t/nixos-install-fails-building-hwdb-bin/69750/6 "2025-09-25T15:47:35Z")
Well in an attempt to make myself more informed and give a more complete answer I decided to deliberately break a build and run it with `nix-build -K` so I could show you it was under `/tmp` (I know this wouldn’t answer the installer question, but one thing at a time).
```auto
error: could not compile `XXX` (bin "XXX") due to 1 previous error; 4 warnings emitted
note: keeping build directory '/nix/var/nix/builds/nix-666327-2838463246/build'
```
So not `/tmp`.
```auto
~/src/work/xxx/xxx inline-pkgs +1 !1 ▼ impure 16:40:35
❯ ll /nix/var/nix/builds/nix-666327-2838463246/build
drwxr-xr-x - nixbld1 25 Sep 16:38 cargo-vendor-dir
.rw------- 8.0k nixbld1 25 Sep 16:38 env-vars
drwxr-xr-x - nixbld1 25 Sep 16:38 xxx
.rw------- 111 nixbld1 25 Sep 16:38 tmp.4I0df9OtRn
```
I am pretty confident `tmp.4I0df9OtRn` is the private builder tmp.
I had forgotten that [2.30](https://nix.dev/manual/nix/2.31/release-notes/rl-2.30.html) moves default build-dir because of [reasons](https://discourse.nixos.org/t/security-advisory-privilege-escalations-in-nix-lix-and-guix/66017). So ignore everything I said about builds in `tmpdir` it’s all out of date, and it happens in `/nix`. Which doesn’t answer the installer question.
EDIT: having spent 30 seconds reading the installer, the call to `nix-build` has an undocumented `--store` (afaict) option that uses the mount point, so I would assume builds happen under `/mnt/nix`.
---
### Author:  [@zwol](https://discourse.nixos.org/u/zwol)
#### Post date: [September 25, 2025, 5:17pm UTC](https://discourse.nixos.org/t/nixos-install-fails-building-hwdb-bin/69750/7 "2025-09-25T17:17:32Z")
Thanks, this is helpful. I am doing weird things with `/nix/var` (kitbashed ephemeral root; not using `impermanence`) and it’s quite possible that the builds directory wound up in a space that is very small and/or mounted noexec. I have to suspend working on this for the moment but I have some concrete things to try now, at least.