QEMU can allow guests to access more than one host core at a time.
Previously, this had to be done via ad-hoc arguments:
virtualisation.qemu.options = ["-smp 12"];
Now you can simply specify:
virtualisation.cores = 12;
Overlayfs is quite a bit faster, e.g. with it the KDE 5 test takes ~7m
instead of ~30m on my laptop (which is still not great, since plain
9pfs is ~4m30s).
This works around:
machine: must succeed: nix-store -qR /run/current-system | grep nixos-
machine# error: changing ownership of path ‘/nix/store’: Invalid argument
Probably Nix shouldn't be anal about the ownership of the store unless
it's trying to build/write to the store.
http://hydra.nixos.org/build/45093872/nixlog/17/raw
(cherry picked from commit 57a0f14064)
Previously we were using two or three (qemu_kvm, qemu_test, and
qemu_test with a different dbus when minimal.nix is included).
(cherry picked from commit 8bfa4ce82e)
- most nixos user only require time synchronisation,
while ntpd implements a battery-included ntp server (1,215 LOCs of C-Code vs 64,302)
- timesyncd support ntp server per interface (if configured through dhcp for instance)
- timesyncd is already included in the systemd package, switching to it would
save a little disk space (1,5M)
The reason to patch QEMU is that with latest Nix, tests like "printing"
or "misc" fail because they expect the store paths to be owned by uid 0
and gid 0.
Starting with NixOS/nix@5e51ffb1c2, Nix
builds inside of a new user namespace. Unfortunately this also means
that bind-mounted store paths that are part of the derivation's inputs
are no longer owned by uid 0 and gid 0 but by uid 65534 and gid 65534.
This in turn causes things like sudo or cups to fail with errors about
insecure file permissions.
So in order to avoid that, let's make sure the VM always gets files
owned by uid 0 and gid 0 and does a no-op when doing a chmod on a store
path.
In addition, this adds a virtualisation.qemu.program option so that we
can make sure that we only use the patched version if we're *really*
running NixOS VM tests (that is, whenever we have imported
test-instrumentation.nix).
Tested against the "misc" and "printing" tests.
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
This allows setting options for the same LUKS device in different
modules. For example, the auto-generated hardware-configuration.nix
can contain
boot.initrd.luks.devices.crypted.device = "/dev/disk/...";
while configuration.nix can add
boot.initrd.luks.devices.crypted.allowDiscards = true;
Also updated the examples/docs to use /disk/disk/by-uuid instead of
/dev/sda, since we shouldn't promote the use of the latter.
Allow usage of list of strings instead of a comma-separated string
for filesystem options. Deprecate the comma-separated string style
with a warning message; convert this to a hard error after 16.09.
15.09 was just released, so this provides a deprecation period during
the 16.03 release.
closes#10518
Signed-off-by: Robin Gloster <mail@glob.in>
This reverts commit 6353f580f9.
Unfortunately cache=none doesn't work with all filesystem options.
Hydra tests error out with: file system may not support O_DIRECT
See http://hydra.nixos.org/build/30323625/
As @domenkozar noted in #10828, cache=writeback seems to do more harm
than good:
https://github.com/NixOS/nixpkgs/issues/10828#issuecomment-164426821
He has tested it using the openstack NixOS tests and found that
cache=none significantly improves startup performance.
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
This seems to be the root cause of the random page allocation failures
and @wizeman did a very good job on not only finding the root problem
but also giving a detailed explanation of it in #10828.
Here is an excerpt:
The problem here is that the kernel is trying to allocate a contiguous
section of 2^7=128 pages, which is 512 KB. This is way too much:
kernel pages tend to get fragmented over time and kernel developers
often go to great lengths to try allocating at most only 1 contiguous
page at a time whenever they can.
From the error message, it looks like the culprit is unionfs, but this
is misleading: unionfs is the name of the userspace process that was
running when the system ran out of memory, but it wasn't unionfs who
was allocating the memory: it was the kernel; specifically it was the
v9fs_dir_readdir_dotl() function, which is the code for handling the
readdir() function in the 9p filesystem (the filesystem that is used
to share a directory structure between a qemu host and its VM).
If you look at the code, here's what it's doing at the moment it tries
to allocate memory:
buflen = fid->clnt->msize - P9_IOHDRSZ;
rdir = v9fs_alloc_rdir_buf(file, buflen);
If you look into v9fs_alloc_rdir_buf(), you will see that it will try
to allocate a contiguous buffer of memory (using kzalloc(), which is a
wrapper around kmalloc()) of size buflen + 8 bytes or so.
So in reality, this code actually allocates a buffer of size
proportional to fid->clnt->msize. What is this msize? If you follow
the definition of the structures, you will see that it's the
negotiated buffer transfer size between 9p client and 9p server. On
the client side, it can be controlled with the msize mount option.
What this all means is that, the reason for running out of memory is
that the code (which we can't easily change) tries to allocate a
contiguous buffer of size more or less equal to "negotiated 9p
protocol buffer size", which seems to be way too big (in our NixOS
tests, at least).
After that initial finding, @lethalman tested the gnome3 gdm test
without setting the msize parameter at all and it seems to have resolved
the problem.
The reason why I'm committing this without testing against all of the
NixOS VM test is basically that I think we can only go better but not
worse than the current state.
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
We already have separate tests for checking whether the ISO boots
correctly, so it's not necessary to do that here. So now
tests/installer.nix just tests nixos-install, from a regular NixOS VM
that uses the host's Nix store. This makes running the tests more
convenient because we don't have to build a new ISO after every
change.
The Nixos Qemu VM that are used for VM tests can now start without
boot menu even when using a bootloader.
The Nixos Qemu VM with bootloader can emulate a EFI boot now.
Fixes#2379.
The new name was a misnomer because the values really are X11 video
drivers (e.g. ‘cirrus’ or ‘nvidia’), not OpenGL implementations. That
it's also used to set an OpenGL implementation for kmscon is just
confusing overloading.
Apparently systemd is now smart enough to figure out predictable names
for QEMU network interfaces. But since our tests expect them to be
named eth0/eth1..., this is not desirable at the moment.
http://hydra.nixos.org/build/10418789
Using pkgs.lib on the spine of module evaluation is problematic
because the pkgs argument depends on the result of module
evaluation. To prevent an infinite recursion, pkgs and some of the
modules are evaluated twice, which is inefficient. Using ‘with lib’
prevents this problem.
Needed for the installer tests, since otherwise mounting a filesystem
may fail as it has a last-mounted date in the future.
http://hydra.nixos.org/build/9846712
