[systemd-devel] Fwd: [PATCH] Add support for detecting NIC partitions on Dell Servers

[Jordan Hargrave]

On Tue, Nov 10, 2015 at 4:53 AM, Kay Sievers <kay at vrfy.org> wrote:
> On Tue, Nov 10, 2015 at 5:49 AM, Jordan Hargrave <jharg93 at gmail.com> wrote:
>> Cleaned up linux coding style
>>
>> This patch will integrate some of the features of biosdevname into systemd.
>> The code detects the port and index for detecting NIC partitions. This creates
>> a new environment variable, ID_NET_NAME_PARTITION of the format
>> <PORT>_<PARTITION>
>>
>> The patch will also decode SMBIOS slot number for NIC, and store in the variable
>> ID_NET_NAME_SMBIOS_SLOT.  Systemd does not have a method for naming
>> ports on a multi-port card plugged into a slot.
>
> Again, I don't think systemd should carry an SMBIOS parser.
>
> Sorry,
> Kay

>From a customer usability standpoint, having the slot numbers as part
of systemd would be a very useful feature.  The current method only
works for single-port NICs in a slot.  Multi-port NICs, especially
ones with SR-IOV or multiple partitions get garbled names like

enp4s0
enp4s1
enp4s0d1
enp4s0f1
enp4s0f2
enp4s0f3
enp4s0f4
enp4s0f5
enp4s0f6
enp4s0f7
enp4s0f1d1
enp4s0f2d1
enp4s0f3d1
enp4s0f4d1
enp4s0f5d1
enp4s0f6d1
enp4s0f7d1
enp4s1d1
enp68s0f0
enp68s0f1
enp69s0f0
enp69s0f1

That's another annoying thing with systemd names, the bus number is
*decimal*.  lspci is in hex, so the customer has to do a conversion to
figure out even what PCI device that is.

All enp4xxxx are a dual-port NIC in Slot 3 with 8 SR-IOV devices.

All enp68xx and enp69xxx are a single quad-port NIC in slot 2.
Systemd breaks here if trying to name using slot numbers with the
existing method.  As there are 4 devices under the slot with same
device numbers, systemd would name them
ens2f0
ens2f1
ens2f0
ens2f1

Which causes name collision.  I was able to verify this as either they
got named:
ens2f0
ens2f1
enp69s0f0
enp69s0f1

or
enp68s0f0
enp68s0f1
ens2f0
ens2f1

at startup.

That's the best feature of biosdevname, being able to tell which slot
the NIC is located just from the name.  Systemd still has some
limitations and/or bugs in this regard.