Re: [ANNOUNCE] [PATCHES] Advanced TCA Hotswap Support in Linux Kernel

Greg KH
2002-10-15T00:53:03Z

On Mon, Oct 14, 2002 at 11:42:15AM -0700, Steven Dake wrote:
> lkml,
>
> http://www.sourceforge.net/project/showfiles.php?group_id=64580
>
> I am announcing a sourceforge project for developing support in Linux
> kernel for Advanced TCA (PICMG 3.0) architecture. Advanced TCA is a
> technology where boards exist in a chassis and can either be processor
> nodes or storage nodes. All boards in the chassis are connected by
> FibreChannel and Ethernet. The blades can be hot added or hot removed
> while the Linux processor nodes are active, meaning, that the SCSI
> subsystem must add devices on insertion request and remove devices on
> ejection requests. Further the typical /dev/sda naming of devices is
> not appropriate since device nodes can change depending on the insertion
> order of disks.
>
> These patches are for Linux 2.4.19 and work with the Qlogic 2300
> FibreChannel driver and at this point mostly support hotswap of the disk
> subsystem.

Some questions:
- is there a public spec for this architecture?
- are you going to be generating a 2.5 version of this so that
this feature can be added to the main kernel tree?
- Why don't you use the existing kernel way of notifying
userspace of hotplug events, through /sbin/hotplug?
- You create a lot of new ioctls, which is not nice. You should
probably do what was done for the pci hotplug subsystem, and
create a ram based filesystem for this subsystem. That way
you don't need to have a /dev node, and the userspace tools
become dirt simple.

thanks,

greg k-h