Moving an HD from one comp to another

[Giles Orr]

2010/1/6 Lennart Sorensen <lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org>:
> On Wed, Jan 06, 2010 at 11:49:28AM -0500, Giles Orr wrote:
>> I have a 60Gb USB external 1.8" HD on which I've made a bootable
>> Debian testing installation.  It's intended for my Acer Aspire One,
>> which has a very small (8Gb) and slow SSD on-board.  This isn't a
>> great solution, but it makes some interesting things possible.  The
>> onboard SSD has a fully functional Debian testing install on it.
>>
>> I did the external HD install on another laptop because arranging the
>> install on the AAO was just too much of a pain (it doesn't have a
>> DVD/CD drive and I didn't want to download netinst and make a bootable
>> USB key etc. etc.).  When I plug the external drive into the AAO it
>> boots up fine and everything works great ... except for the wired
>> Ethernet card.  The appropriate kernel modules appear to be loaded (I
>> compared it against the module list from the working install on the
>> AAO internal HD), but "ifconfig eth0 up" gets this response: "eth0:
>> ERROR while getting interface flags: No such device."  The main
>> difference in the modules list is that three unneeded firewire modules
>> load (the laptop that I did the install on has firewire).  Unloading
>> them doesn't remedy the situation.
>
> Check the udev rules.  Quite likely the eth of the original machine is
> listed as eth0 (when detected) and the new machine is probably now eth1.
> You can fix that up.  Usually found in /etc/udev/rules.d/*persistent*net*
> (I forget the exact name).

Exactly right, as usual.  Thank you!!

>> Is there a simple way to convince the install to re-run the checks for
>> what modules to load, and/or to do the NIC set-up again?  Or is there
>> some other way to solve this?  Thanks.
>
> See above.
>
>> For the curious, the external HD is noticeably but not hideously
>> slower than the internal SSD.  What I'm mostly doing this for is so
>> that I have the room to compile a custom kernel for the system.
>
> USB is slow and very cpu intensive compared to pretty much any other
> interface you could connect a disk to.
>
> firewire, SATA, UDMA IDE, etc all have DMA to offload the cpU.
>
> Given netbooks usually use atom CPUs, you don't have much cpu available
> to begin with.  Also 1.8" disks are generally rather slow compared to
> bigger disks.  Also the SSD has the advantage of no access time to worry
> about, while a 1.8" disk will have a rather long access time because of
> the low rotation speed.

I've always known that USB caused very high CPU loads.  Now I know why
- thanks.  As I said - it's slow, but tolerable so I'll probably
continue to use it.  It's a trade-off I'm willing to make.

-- 
Giles
http://www.gilesorr.com/
gilesorr-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org
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