/usr on USB

[Matt Zimmerman]

On Wed, Sep 22, 2004 at 08:09:11AM +0800, John wrote:

> Matt Zimmerman wrote:
> 
> >My interpretation would be "you cannot put /usr on a hot-plugged device",
> >which seems equally sane.
> 
> I booted with the drive in place. It's no more transient than, say, an 
> NFS mount. The network might go away, just as some twit might pull the 
> drive out.

Likewise, it's no less transient than a keyboard or mouse. :-)

But seriously, there's only so much infrastructure we can promote earlier in
the boot process to accomodate extreme filesystem configurations.  Linux
provides a lot of flexibility in this area; filesystems can be driven from
userspace, and rely on LDAP servers, HTTP proxies, VPN links, and other
things which are brought up later in the boot process.

> It should no more problematic than booting from USB.

I've never tried booting from a USB hard disk; I imagine the BIOS would have
to provide some emulation help, or else the boot loader would never cope.

> Oh, I think Hot Plug won't cope with an nfs mount for /usr either.

Yes, I think we may have inadvertently broken that with an optimisation.
I'll look into it.  NFS gets special treament, and is mounted later in the
boot process.  USB doesn't (and couldn't use the same mechanism).

-- 
 - mdz