running linux off usb hdd

linuxmandrake · 10-08-2006, 02:55 PM

I have seen various tutorial on booting linux off usb even if theres no bios support using grub. Would I have any problems if I run this setup on different pcs with different hardware. I dont need sound I just need KDE? I would think I would have problems with xserver because of the different video cards.

Simon Bridge · 10-08-2006, 05:44 PM

I'd anticipate you'd have to reconfigure the video and sound each time.

However - you could set up X to use a low/generic resolution and driver each time, then you'll still be able to boot. Really depends what you want to use it for.

I understand that if you want to boot from an external drive on a machine that does not support this in bios, then you also need a boot-disk for the machine or a boot image etc on that machine's hard drive.

linuxmandrake · 10-09-2006, 08:29 AM

Well am only using it for programming (php no hardcore graphics involved). So all I need is KDE running at 1024*768 resolution. I 'm not bothered about the sound. I dont want any irrating messages by kde saying it cant start the sound though. Fine I'm allowed to boot from floppy. Could the boot image be on cdrom? Floppies are alitlle unreliable and god damn slow!

darinbolson · 10-09-2006, 02:13 PM

does it HAVE to be KDE or would another environment work? If you have a large enough usb drive, you could use puppy on usb and have multiple saved configurations that you could choose from at boot.

oooh, I see a kde puppy at murga's website.

linuxmandrake · 10-09-2006, 06:18 PM

not too bothered about that

Simon Bridge · 10-11-2006, 08:37 PM

Quote:

Well am only using it for programming (php no hardcore graphics involved). So all I need is KDE running at 1024*768 resolution.

That should be fine, so you manually set X to use the vesa driver and that resolution and only really weird configurations will be messed up. The worst that will happen is that you'll be unable to configure the soundcard (nvidia/radeon say) so you'll be forced to boot to text-only - from where you get X to use the open source drivers ... some distros will autodetect this anyway when they boot. If I were you, I'd try it an see.

Quote:

I 'm not bothered about the sound. I dont want any irrating messages by kde saying it cant start the sound though. Fine I'm allowed to boot from floppy. Could the boot image be on cdrom? Floppies are alitlle unreliable and god damn slow!

I've never personally done this, however it is quite possible to use SBM (?) on a floppy as the initial boot-loader, which can then load a decent boot image off a CD or anyplace else (i.e. the usb drive). You have quite a bit of reading to do to understand the setup required for your exact circumstances though.

I think here is a good place to start. It seems to deal with your situation quite specifically, vis:

Quote:

The article delves into two approaches. The first is a single-stage method that relies on several kernel patches that cause Linux to do a second bootup scan for emulated SCSI devices, such as USB mass storage or FireWire drives. This second scan enables the OS to identify and use drives not recognized by the BIOS but which are recognized by the kernel (kernel modules don't count, here).
The second, preferred approach involves placing the kernel and an initrd filesystem image on a boot partition recognized by the BIOS. The kernel must support initrd images -- most do. The kernel boots, mounts the initrd image on a RAM disk as the temporary root filesystem, and executes the /linuxrc script that it contains. The script then attempts to load the kernel modules needed to support the device containing the real root filesystem (the external USB/FireWire drive), and attempts to create a device file for it. When the script exits, the kernel unmounts and destroys the temporary root filesystem and mounts the real root filesystem from the external drive before proceding to boot.

... (my emphasis) sound good?

The second approach is what I was talking about - though, if you want to compile the usb driver into a custom kernel, the first approach may be better for you - especially as you don't want the "cannot activate sound" message - you could disable alsa in your custom image.