4.0 - kernel packages in linux templates ?

[Ivan Mitev]

Hi,

Given that linux templates boot a kernel provided by qubes, what's the
rationale of having kernel packages installed in the default linux
templates ? Is it only to be able to run them as HVM ?
If yes, when using pv, can they be safely removed or is there something
else that depends on those packages ?

The reason I'm asking is that removing the kernel packages in the
template would:
- save a bit of space (more so when doing frequent backups)
- with the kernel release churn, avoid frequently downloading and
installing large packages when updating templates (more so when multiple
templates are setup).

cheers,
ivan

[Marek Marczykowski-Górecki]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256

On Fri, Apr 20, 2018 at 09:27:13AM +0300, Ivan Mitev wrote:
> Hi,
>
> Given that linux templates boot a kernel provided by qubes, what's the
> rationale of having kernel packages installed in the default linux
> templates ? Is it only to be able to run them as HVM ?
> If yes, when using pv, can they be safely removed or is there something
> else that depends on those packages ?

In all the cases you can choose to use that kernel, but you can also use
the one provided from dom0. For a long time we plan to move completely
to use a kernel from inside VM, because it is much easier to handle (for
example installing custom kernel modules just works), but every single
time we find a thing that block us from this change (this time it is
PVH, which currently do not support pvgrub-like bootloader).

See here:
https://www.qubes-os.org/doc/managing-vm-kernel/#using-kernel-installed-in-the-vm

> The reason I'm asking is that removing the kernel packages in the
> template would:
> - save a bit of space (more so when doing frequent backups)
> - with the kernel release churn, avoid frequently downloading and
> installing large packages when updating templates (more so when multiple
> templates are setup).

There is nothing Qubes specific requiring you to have kernel in each
template (unless you choose to use it). The one package that would be
removed too (qubes-kernel-vm-support) is needed _for_ kernels in VM, not
the other way around.

- --
Best Regards,
Marek Marczykowski-Górecki
Invisible Things Lab
A: Because it messes up the order in which people normally read text.
Q: Why is top-posting such a bad thing?
-----BEGIN PGP SIGNATURE-----

iQEzBAEBCAAdFiEEhrpukzGPukRmQqkK24/THMrX1ywFAlrZov0ACgkQ24/THMrX
1yyOdQf8CeVivcT7BBVy4kqfj784JuAN/vEp1RAqTopGMUA4b1t4VAnmyXj52nn8
Rw++L4p38piOUd1K9Eqo3K1VSkW2gtGGMKOfKBMQ0AZSvUpeDfEZ8WFBBvTIXcl+
4vD8dauSwZL8PffczAKlOJrkf+X2zjFNKp4l+x4Y/c8lEvKE6DG8D4H+MOaroOLI
uj2o0rcILBRRHgrEkS0bKgfna9ouCJV0mDPdj/NVX9xxeT4XZtvCw4H2timgX1wz
T9/L3VKHBW7kJJZD/FSPDWSGxXGv9P3vvQmqNI9HEnV3etGyvJf488Pmy45ZTCx+
hKOe2lnkb7Mt5sgQqSfFQAdD+18i/A==
=r3Ka
-----END PGP SIGNATURE-----

[Ivan Mitev]

Thanks for the quick, informative answer !