FibreChannel support

[Dan Nelson]

In the last episode (Sep 15), Paul said:
> Is there anyone using fibrechannel SAN solutions with FreeBSD ?

I had a FreeBSD running on a SAN using qlogic cards a few months back
but had to put Linux on it.  It works fine.
 
> I have a couple questions:
> 
> 1) Is concurrent access possible ? Like in a server cluster
>    csenario where multiple servers share the same LUN ?

You can whare the LUN, but only one system can have the filesystem
mounted.  There are no shared-storage filesystems for FreeBSD (and I
don't really trust the ones for Linux yet).  The easiest setup is an
active/passive system, where the master has the fs mounted and holds an
aliased IP.  When it fails, the slave mounts the volume and grabs the
IP.  That should allow remote NFS access at least to continue
transparently.

> 2) Is there a way to grow partitions when more drives are added to
>    the SAN array ?

Sure.  If don't put any FDISK or disklabel partitions on the lun (i.e.
you put the filesystem directly on /dev/da#), it's really easy. 
Dismount the volume, run "camcontrol rescan da#" to let the system
detect the new size, run "growfs /mountpoint", remount.

-- 
	Dan Nelson
	dnelson at allantgroup.com