/usr on USB

[John]

Matt Zimmerman wrote:

>On Wed, Sep 22, 2004 at 08:09:11AM +0800, John wrote:
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>>Matt Zimmerman wrote:
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>>>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.
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>Likewise, it's no less transient than a keyboard or mouse. :-)
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 From what I hear, hotplugging PS/2 can fry the mobo. A mate had a bad 
experience, so I don't do it any more.

>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.
>
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>>It should no more problematic than booting from USB.
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>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.
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Didn't you say you have a Powerbook? I am pretty sure that will boot 
from firewire.

My HP Evectra boots from USB. I hear thumbdrives and such are pretty 
handy recovery devices because people can boot from them. Isn't that how 
d-i installs from one? People also like them fir firewalls, so I guess 
lots of people boot them,

Depending on the USB interface, I can get to about 30 Mbytes/sec on my 
USB drive. Running Ubuntu off it is a reasonable proposition: I install 
on it here, take it to my brothers' place about 14 Km away, run it on 
his machine, maybe boot it in Internet Cafes around the world on my next 
world trip (whether they'd allow it isn't the issue).


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>>Oh, I think Hot Plug won't cope with an nfs mount for /usr either.
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>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).
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Tried NFS over wireless? As I've pointed out, the standard Ubuntu 
requres /usr to load wireless' firmware.