[Cialug] CentOS 7

[Daniel A. Ramaley]

That extra detail helps me to understand the value of the new design. 
Thank you.

On 2014-07-09 at 12:40:45 Zachary Kotlarek wrote:
> Mostly they’re just moving toward the state-of-the-art-of-2007 wherein
> visible device names should be stable, user-defined, and in no way
> tied to the underlying hardware address. It’s very important for
> things like USB devices and disks where ordering changes all the time
> it doesn’t make any sense to specifically exclude hardware type A or
> B from that plan just because the hardware address for it are
> somewhat stable on some systems where the hardware never changes.
> 
> So in answer to “what problem” I’d suggest “the one where the name
> changes between boots”. It’s more common with things on shared busses
> than with NICs, but it happens to anything given the right
> circumstances. There’s no guarantee that cards will always scan in
> the same order (many boards do, but it’s not required), and certainly
> if you installed a new card, or even physically re-arranged them,
> they’ll come up with different interface numbers and you’ll have to
> re-map them manually. Or imagine a boot disk used on more than one
> hardware system. Or replacing a motherboard with one that scans in a
> different order. Or any of 100 other things that could change the
> device hardware addresses.
> 
> Another is the problem is not knowing what “eth0” and “eth1”
> represent. A router with interfaces named “uplink” and “LAN” or a
> laptop with interfaces named “wifi” and “ether” are simply easier to
> administrate in the same way that the hostnames “test.foo.com” and
> “prod.foo.com” are easier to use than the underlying network
> addresses.
> 
> Another is removing all of the forced naming conventions that relate
> to underlying hardware type — why does my T1 card have a different
> device naming convention than my DSL card which is still different
> from the Ethernet card? Why does my IP and higher-level configuration
> care that I changed the underlying device type?
> 
> Also note that both the names and the matching criteria are
> user-defined, so if you still want to name things by PCI address
> instead of MAC address you can do so simply by editing the config
> file.
> 
> What’s the downside to stable, user-defined, path-independent names?
> 
> 	Zach
__
Daniel A. Ramaley
Network Engineer 2

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