| 14 Mar 2026 |
 Mic92 | * Has been to long since I read that. I think it did something like read into mmap? This would actually not be direct Io but don't remember the mmap flags it used | 19:55:19 |
| Mic92 | Some of them tell the Kernel to not bother with page cache | 19:56:06 |
 matthewcroughan | I think it is somehow dependent on the host | 20:04:40 |
| matthewcroughan | I have a reproducer now that only fails sometimes | 20:04:47 |
| matthewcroughan | Either that or it is dependent on some randomness | 20:05:42 |
| matthewcroughan | does xargs sort things on the way in? | 20:05:54 |
 lassulus | good question, maybe not | 20:06:20 |
| matthewcroughan | even if it was that, and you sorted it, that only means for the same closure you would get the same bug, rather than it failing randomly | 20:06:45 |
| matthewcroughan | but the root cause would still be there | 20:06:51 |
| lassulus | maybe we just create like 8x1gb files and copy that into the new image? for a reproducer | 20:07:02 |
| Mic92 | In reply to @lassulus:lassul.us
good question, maybe not Should be stable because closure info stays the same | 20:19:38 |
| Mic92 | The parallel flag might introduce some non-determinism | 20:20:07 |
| matthewcroughan | lassulus: if you want a minimal reproducer for ZFS | 20:29:49 |
| matthewcroughan | no PR needed | 20:29:57 |
| matthewcroughan | diff --git a/tests/make-disk-image.nix b/tests/make-disk-image.nix
index eb81f15..2308836 100644
--- a/tests/make-disk-image.nix
+++ b/tests/make-disk-image.nix
@@ -5,10 +5,11 @@
(pkgs.nixos [
../module.nix
- ../example/simple-efi.nix
+ ../example/zfs.nix
(
{ config, ... }:
{
+ networking.hostId = "8425e349";
documentation.enable = false;
system.stateVersion = config.system.nixos.release;
disko.memSize = 2048;
| 20:30:00 |
| matthewcroughan | This will cause a kernel panic | 20:30:10 |
| matthewcroughan | nixos-disko-images> + zfs create -up zroot/encrypted -o encryption=aes-256-gcm -o keyformat=passphrase -o keylocation=file:///tmp/secret.key -o mountpoint=none
nixos-disko-images> cannot create 'zroot/encrypted': Failed to open key material file: No such file or directory
Maybe that's the reason though?
| 20:30:40 |
| matthewcroughan | Yeah okay, maybe that's all it is.. | 20:31:56 |
| lassulus | seems like it can't find the key | 20:34:16 |
| lassulus | so probably unrelated | 20:34:20 |
| matthewcroughan | but how does this succeed in the installer test ? | 20:34:30 |
| matthewcroughan | but not in disk image building | 20:34:33 |
| matthewcroughan | is the exit code ignored in the installer test? | 20:34:40 |
| lassulus | it probably creates /tmp/secret.key? | 20:34:48 |
| matthewcroughan | ah yeah it does | 20:35:00 |
| matthewcroughan | lib/tests.nix does this for tests | 20:35:13 |
| matthewcroughan | Okay, so imageSize being set wrong, or errors in the disko config can both lead to kernel panics | 20:37:30 |
| matthewcroughan | and ofc not enough space | 20:37:51 |
| lassulus | hm errors in the config should lead to eval errors | 20:37:58 |
| matthewcroughan | so it's very easy to conflate that with other things, but I think I have an actual reproducer now | 20:38:01 |
