Subject: Re: [PATCH 2.6.23.12] net/bonding: option to specify initial bond interface number

From: Jay Vosburgh <[email-masked]>
Date: Thu, 03 Jan 2008 09:03:51 -0800

Jari Takkala <[email-masked]> wrote:

>On Wednesday, January 02, 2008 17:24, Jay Vosburgh wrote:
>> 	What advantage does this have over:
>> 
>> # echo +bond5 > /sys/class/net/bonding_masters
>> 
>> 	which will create a new bonding master for the already-loaded driver?
>>
>
>The advantage is that you can load multiple instances of the bonding
>driver and control the name of the bond interface that will be
>created. Normally the bond interface name would take the next available
>number.
>
>In our startup scripts we need to be able to ensure that the interface
>name is consistent across reboots. Sometimes bond1 may be brought up
>before bond0 and it may have different options (requiring a different
>instance of the bonding driver).

	With the sysfs interface to bonding, your last statement is not
true; any number of bonding interfaces, with arbitrary names, can be
created and have their options set without loading multiple instances of
the bonding driver.

>I understand that the startup scripts could be modified to account for
>this, however we also have an IOS like interface to an embedded system
>where the user can create new bond interfaces and specify the interface
>number, they may create interfaces out of order and this feature enables
>them to accomplish that.

	Does your embedded system have sysfs available?  If it does,
then it's to your advantage to use the sysfs API; for one thing, the
single instance of the bonding driver with all interfaces through it
should utilize fewer resources than loading the driver repeatedly.

	-J

---
	-Jay Vosburgh, IBM Linux Technology Center, [email-masked]