On Tue, 14 Aug 2001, Andi Kleen wrote:
> One big problem in my opinion is how the MII monitoring is implemented.
...
> It uses ioctls that are marked for removal already in vger..
The MII ioctls are not marked for removal. Instead something far more
destructive was done: the ioctl constant was changed without changing the
name. This breaks both forward and backwards compatibility.
That's a very nasty way to get rid of an interface. (Or should I go
with the other end of the malice/incompetence tradeoff..)
> In addition it is a bit useless in my opinion. MII monitoring alone
> is never enough to assure HA, because there can be lots of other reasons why
> the other host can go belly up without losing the ethernet link
You should be precise: monitoring link beat (generally, not just MII
management data) specifically) covers only a small percentage of network
problems. For instance machines crash and switches / routers usually
fail while still generating link beat.
The MII ioctls provide information about the physical link layer, so you
can diagnose if the failure was due to a local cable problem. Some
transceivers will even report approximately how far away a cable
break/kink is.
Donald Becker becker@xxxxxxxxx
Scyld Computing Corporation http://www.scyld.com
410 Severn Ave. Suite 210 Second Generation Beowulf Clusters
Annapolis MD 21403 410-990-9993
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