Upgrading VPS from single core to multi-core isn't automatically recognized

[openletter]

I just noticed that when I upgrade my VPS from a 1 core to 2 core plan, OpenBSD does not automatically recognize the change.

I can see:

# sysctl hw.ncpu
hw.ncpu=1
# sysctl hw.ncpufound
 hw.ncpufound=2
# sysctl hw.ncpuonline
hw.ncpuonline=1

What would be the better way to configure the second core?

Note the ISP is Vultr and I installed from http using bsd.rd (as most excellently recommended by another forum user here).

[jggimi]

• OpenBSD's GENERIC kernel is a single-processor configuration. The name of this kernel in installation media is "bsd".
• OpenBSD's GENERIC.MP kernel is the multi-processor configuration, and the name of this kernel in installation media is "bsd.mp".

At install time, if the system is single-processor, the GENERIC "bsd" kernel is copied to the new root filesystem as "/bsd", the GENERIC.MP kernel "bsd.mp" is copied to the new root filesystem as "/bsd.mp".

At install time, if the system is multi-processor, the GENERIC "bsd" kernel is copied and renamed to the new root filesystem as "/bsd.sp" and stored in the event it needs to be used, while the GENERIC.MP "bsd.mp" kernel is copied and renamed to the new root filesystem as "/bsd", the name of the default kernel file.

You do not need to reinstall. You can rename these kernel files:

# cd /
# mv bsd bsd.sp
# mv bsd.mp bsd

Then re-enable randomly linked kernels (KARL) for the next boot with:

# sha256 -h /var/db/kernel.SHA256 /bsd

[openletter]

The only bsd files I have in / are /bsd, /bsd.booted, and /bsd.rd.


I did find elsewhere posts about /bsd.mp, but they were some years old and I wasn't clear if maybe things have changed?

[jggimi]

Then bsd.mp wasn't included during your initial install. You can try upgrading to 7.0 again, and pick up the file during that process, or, copy it from installation media.

[openletter]

During the reboot I got the message:

reorder_kernel: failed -- see /usr/share/relink/kernel/GENERIC.MP/relink.log

In the file:

# cat 
/usr/share/relink/kernel/GENERIC.MP/relink.log
(SHA256) /bsd: OK
make: don't know how to make newbsd
Stop in /usr/share/relink/kernel/GENERIC.MP

And now I have the following:

# sysctl hw.ncpu
hw.ncpu=2
# sysctl hw.ncpufound
 hw.ncpufound=2
# sysctl hw.ncpuonline
hw.ncpuonline=1

[openletter]

Okay, so I failed to read correctly. Apparently I ran the relink command before rebooting. Let met reinstall and try again, because now I still get the message with the log entry:

(SHA256) /bsd: OK
make: don't know how to make newbsd
Stop in /usr/share/relink/kernel/GENERIC.MP

[openletter]

I did a reinstall with the 2 core instance, and I noticed that it installed bsd.mp as the kernel (I then destroyed the instance).

I did an install on a single core instance and I noticed that it did not even give the option to install bsd.mp.

I upgraded the patches, rebooted, upgraded the instance, downloaded bsd.mp, followed the above instructions, and now I still get the message:

reorder_kernel: failed -- see /usr/share/relink/kernel/GENERIC.MP/relink.log

In the log file:

(SHA256) /bsd: OK
make: don't know how to make newbsd
Stop in /usr/share/relink/kernel/GENERIC.MP

[openletter]

I just noticed that the Vultr single core default install image uses bsd.mp kernel:

# ls /bsd*
/bsd    /bsd.booted  /bsd.rd    /bsd.sp
# strings /bsd | grep ^GENERIC.MP
GENERIC.MP#232

(BTW, not saying this is a good idea, just sharing an observation.)

[openletter]

I was able to safely get bsd.mp installed by booting into bsd.rd and selecting (U)pgrade.

When I got to the set selection, I could see [x] bsd.mp was there and later in the process it printed the message "Multiprocessor machine: using bsd.mp instead of bsd."

I am still stuck with hw.ncpuonline=1. I'm wondering if this has more to do with the security restrictions on Intel CPUs or hyper-threading that, frankly, I don't know enough about.