On 06/21/2011 01:52 PM, Bill Nottingham wrote:
Don Dutile (ddutile(a)redhat.com) said:
> On 06/20/2011 05:09 PM, Bill Nottingham wrote:
>> I'm considering drop the network hotplug support from the 'network'
>> service. This is the code that would automatically run ifup when a new
>> network device appeared, if there was a configuration for it.
>>
>> The supported solution would be to use NetworkManager for these usage
>> cases (or wicd, or netplugd, or conman...) Alternatively, just run
>> ifup yourself.
>>
>> Currently, this would happen in the following cases:
>> 1. USB and/or expresscard hotplugged ethernet/wireless
>> 2. PCI hotswap of a network card
>> 3. Runtime addition of network interfaces in virtual system
>> 4. Admin manually removes and reloads a driver module
>>
>> For #1, those systems are generally better served by NM.
>> For #2, this is something with such heavy admin interaction that I
>> would suspect that it would be preferred to handle it manually. (Also,
>> swapping hardware likely invalidates the configuration in any case.)
>> For #3, you're unlikely to have a configuration written for a freshly
>> available device.
> sorry, I don't understand this statement....
> but has me worried for virt hot add/remove of assigned devices
Essentially, hot-adding a virtual device would not bring the device
up automatically if you're using the old network service; you'd have
to run 'ifup' by hand.
hot-adding a VF-nic to a Linux kvm guest brings up the hot-added (VF)
nic in the guest today.... am I missing what you mean?
>> For #4, bringing up the device automatically can cause more
issues
>> than it solves. (We've seen this happen for vlans, for example.)
> This is done all the time (on KVM hosts) to take down PF driver& load
> PF+VF drivers for SRIOV-capable devices.
This would be a different device with a different hardware address,
correct?
Nope; typically start up an SRIOV device in PF-only mode (igb, for
example), then do an rmmod igb; modprobe igb max_vfs=7; same PF mac;
new VF mac's.
and as VF's are added & removed from guests, they may be removed & added
back to host.
Bill