[systemd-devel] Proposal: integrate biosdevname into systemd tree

[Reindl Harald]

Am 04.01.2013 10:40, schrieb Alexander E. Patrakov:
> 2013/1/4 Reindl Harald <h.reindl at thelounge.net>:
>> but hopefully /etc/udev/rules.d/70-persistent-net.rules will be recognized
>> forever if it exists because there are many servers especially virtual
>> ones where you hardly need to control ethernet device names to avoid
>> breaking iptables-scripts as example
> 
> Yes, the existing rules will continue to be recognized. The bug is
> that even they are intrinsically unreliable (as happened with that
> rented server), so I think you actually don't want that.

how can something like this be unreliable?
hwaddresses does not change randomly

SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:50:56:bd:00:04", ATTR{dev_id}=="0x0",
ATTR{type}=="1", KERNEL=="eth*", NAME="eth0"

>> keep in mind there are MANY setups which do not need nor want
>> biosdevname and are bootet with biosdevname=0 on the kernel line
> 
> And that's indeed something that we need to think about. The real
> problem is that it is hard to explain the whole interface-renumbering
> issue and the reasons why he needs persistence to an average sysadmin.
> It's too low level. IMHO it is safer to always install biosdevname and
> use it even if not strictly required than to rely on the sysadmin to
> know about the issue.

currently syaadmins who knew over years how to handle
70-persistent-net.rules are more pissed of than ever before

>> P.S.: i HATE it to need "ifconfig -a" and hack "70-persistent-net.rules"
>> by hand instead as all the years open it and change back the last line
>> to "eth0" after probe-restore of a virtual machine to temporary access
>> a datarecovery backup from some weeks ago
> 
> With biosdevname, the interface names are determined only by PCI bus
> slot. I.e., if the replacement card is inserted into the same slot as
> the failed one

you are missing the real problem with the new shiny biosdevname
nobody can rely on eth0 any longer

if have thousands of firewall-scripts and configurations which
are assuming eth0=LAN, eth1=WAn as example, the benefit of such
scripts is that they can be easily adopted to a new but compareable
setup and basic rules are always the same

with the new shiny names this you have to replace interface names
if you are knowing your scripts and iptables rules you do not
always look "who is WAN interface here", you like to see "eth1"
and know what it does

> the name won't change. And in virtual machines
> biosdevname deactivates itself automatically

fine, even there i stay with force disable it because
after the large changes in a few years i do not trust
any behavior to stay since subsystems are changed and
rewritten like a slut changes her man :-)

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