Gentoo on a USB drive, to be used by 2 computers. Possible?

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DrWoland · Post by **DrWoland** » Sat Oct 01, 2005 3:14 pm

... not simulatenously of course

I want to have a gentoo install on a USB Harddrive so that I can plug it both into my PC and laptop so that I have the same workplace regardless of where I am. I know I can configure a kernel that would have all the right info, but will the rest of it work? Also, here are my main concerns.

Hardware:
If a computer is USB bootable, does it matter what USB drive I use?
Are there USB drives that won't be bootable?
What USB drives are recommended for this purpose, if any?

Logistics:
Theoretically, can one install run on two different sets of hardware? I've tried to imagine it, and it doesn't seem contradictory so far, but if I'm missing something please point it out. I'll just have two parallel installs then with some of the folders mounted to the same partition in /etc/fstab. If there's anything else I'm overlooking please point it out.

I know I had more thoughts on this, but I seriously have forgotten. Please express your ideas on this project and if there's already a how-to on how to do this, feel free to post it and I'll edit the thread to just contain the link. Thanks.

Post by **NeddySeagoon** » Sat Oct 01, 2005 3:42 pm

DrWoland,

What you want to do is perfectly possible. You ned to make your kernel and install for the lowest commom denominator.
e.g. i686 if you want to run on a P4 and a Athlon-XP.

DrWoland · Post by **DrWoland** » Sat Oct 01, 2005 3:45 pm

NeddySeagoon wrote:DrWoland,

What you want to do is perfectly possible. You ned to make your kernel and install for the lowest commom denominator.
e.g. i686 if you want to run on a P4 and a Athlon-XP.

So I don't have to worry about having separate installs, one install with a multi-compatible kernel and no exclusive code optimizations will work for both machines?

Do you know anything about the hardware issues? Will I be able to boot from ANY USB drive?

j-m · Post by **j-m** » Sat Oct 01, 2005 6:35 pm

DrWoland wrote: Do you know anything about the hardware issues? Will I be able to boot from ANY USB drive?

Booting from USB drive is a BIOS problem - either your BIOS supports it or not.

DrWoland · Post by **DrWoland** » Sun Oct 02, 2005 12:37 am

j-m wrote:
DrWoland wrote: Do you know anything about the hardware issues? Will I be able to boot from ANY USB drive?

Booting from USB drive is a BIOS problem - either your BIOS supports it or not.

So ANY USB drive/enclosure will work?

Next concern: The laptop has a Radeon Mobility, the desktop has Nvidia GeForce 4200. Do I just define 2 screens in xorg.conf and it'll try them both?

Omega21 · Post by **Omega21** » Sun Oct 02, 2005 1:55 am

j-m wrote:
DrWoland wrote: Do you know anything about the hardware issues? Will I be able to boot from ANY USB drive?

Booting from USB drive is a BIOS problem - either your BIOS supports it or not.

Yes, you need a BIOS that supports it, although Ive seen some floppy disk images out there that
can be booted off of, that will then boot of a USB device. I have the floppy, but I cant find the image.
Ill post the contents somewhere, later on, and maybe someone could make an image out of them for you.

Best of luck.

DrWoland · Post by **DrWoland** » Sun Oct 02, 2005 4:39 am

Omega21 wrote:
j-m wrote:
DrWoland wrote: Do you know anything about the hardware issues? Will I be able to boot from ANY USB drive?

Booting from USB drive is a BIOS problem - either your BIOS supports it or not.
Yes, you need a BIOS that supports it, although Ive seen some floppy disk images out there that
can be booted off of, that will then boot of a USB device. I have the floppy, but I cant find the image.
Ill post the contents somewhere, later on, and maybe someone could make an image out of them for you.

Best of luck.

Both of my BIOSes have an option to boot off a USB device. I'm tempted to put GRUB on my 512MB traveldrive to test it.

The only thing that concerns me, is for some reason on the ThinkPad, the USB HDD option has a - in front of it (-USBHDD) which the rest of the entries do not... I'm not quite sure what it means but I did google the issue and found plenty of accounts of ThinkPad's booting successfully off of a USB drive. I suppose, if anything, this will be an interesting experiment.

Mr Wonka · Post by **Mr Wonka** » Tue Oct 04, 2005 7:05 pm

I've just got this setup running on my External USB 2 harddrive. Theres a couple of issues I encountered but nothing drastic and other then those it's a straight Gentoo install.

1. Some USB drive take a while to come up. You can't rely on the kernel having access to them when it attempts to mount the root filesystem. To solve this just pass 'rootdelay=X' where X is a number of seconds. I've found 10 to work just fine seeing as my drive takes between 4 and 7 seconds to appear.

2. Grub sees my drives in a different way to the kernel. It seems to swap them over. i.e. sda = hd0 and hda = hd1. This isn't a major stumbling block though. Just make sure to watch where you put that bootloader!

Oh, and none of this will work unless your computers support USB booting.

Hope this helps.

DrWoland · Post by **DrWoland** » Tue Oct 04, 2005 7:12 pm

Mr Wonka wrote:I've just got this setup running on my External USB 2 harddrive. Theres a couple of issues I encountered but nothing drastic and other then those it's a straight Gentoo install.

1. Some USB drive take a while to come up. You can't rely on the kernel having access to them when it attempts to mount the root filesystem. To solve this just pass 'rootdelay=X' where X is a number of seconds. I've found 10 to work just fine seeing as my drive takes between 4 and 7 seconds to appear.

2. Grub sees my drives in a different way to the kernel. It seems to swap them over. i.e. sda = hd0 and hda = hd1. This isn't a major stumbling block though. Just make sure to watch where you put that bootloader!

Oh, and none of this will work unless your computers support USB booting.

Hope this helps.

I'll keep an eye out for #1, #2 I already knew about since it does that with my SATA drive too. Thanks for the heads up, I'll post my progress as soon as the USB enclosure ships. The 300 MB HD is sitting outside my door at home right now

$89, OOHH YEAAAH.

Post by **NeddySeagoon** » Tue Oct 04, 2005 7:50 pm

DrWoland,

300MB for 89$ ?

DrWoland · Post by **DrWoland** » Tue Oct 04, 2005 10:52 pm

NeddySeagoon wrote:DrWoland,

300MB for 89$ ?

EIDE: http://www.tigerdirect.com/applications ... no=1487962
SATA: http://www.tigerdirect.com/applications ... no=1487964
You're welcome

They have both the ATA133 and SATA versions for the same price.

Lepaca Kliffoth · Post by **Lepaca Kliffoth** » Wed Oct 05, 2005 8:35 am

I've already done this. It'll run on ~20 pcs with slightly different hardware (some have sata, some can't boot from usb etc). The USB key is bootable but I also provide a cd to boot it should the BIOS not support boot from usb. It isn't difficultyou just have to make a sane initrd.

alistair · Post by **alistair** » Wed Oct 05, 2005 8:46 am

now i know that you probably want gentoo to be compeletely on the usb drive but couldnt you have also just set up both computers with the same/similar settings and then mounted your usb drive to /home/<user>

Sadako · Post by **Sadako** » Wed Oct 05, 2005 10:29 am

alistair wrote:now i know that you probably want gentoo to be compeletely on the usb drive but couldnt you have also just set up both computers with the same/similar settings and then mounted your usb drive to /home/<user>

This would actually be a far better way of doing things, as not everything would be done over usb, and you'd have better performance simply by having your /home and everything else on two different drives (you could also share other directories, such as /usr/share, /usr/src, /usr/portage, etc.).

It would also make messing around with encrypting the filesystems on the usb drive a lot easier.

DrWoland · Post by **DrWoland** » Wed Oct 05, 2005 2:31 pm

alistair wrote:now i know that you probably want gentoo to be compeletely on the usb drive but couldnt you have also just set up both computers with the same/similar settings and then mounted your usb drive to /home/<user>

I don't want to have to update two computers, maintain two computers, etc. I actually want to unpartition both harddrives as well. I'm not that concerned with performance, so I'm just going to go with this. I'm probably also going to put Ubuntu on there so that it can indeed boot from any machine.

DrWoland · Post by **DrWoland** » Sat Oct 08, 2005 5:50 pm

Should I make a how-to/wiki page on how to do this? Is there a decent how-to already?

airstreamliving · Post by **airstreamliving** » Sat Oct 08, 2005 8:32 pm

DrWoland wrote:
NeddySeagoon wrote:DrWoland,

300MB for 89$ ?
EIDE: http://www.tigerdirect.com/applications ... no=1487962
SATA: http://www.tigerdirect.com/applications ... no=1487964
You're welcome

They have both the ATA133 and SATA versions for the same price.

Tigerdirect is bang-on awesome. I've purchased from them since 1999 and never had any complaints. Once, about three years ago I ordered a 21" monitor - freaking huge. It arrived and a button on the front of it was "stuck" so I called TigerDirect. They authorized a replacement over the phone and UPS came, picked up the monitor and in a few days the replacement arrived. No questions asked. They even gave me a coupon for $30 off my next purchase. I love those guys.

BTW, I have a friend who runs Gentoo off an iPod. Runs great!

Post by **NeddySeagoon** » Sat Oct 08, 2005 10:53 pm

airstreamliving,

DrWoland said 300 Megabytes

airstreamliving · Post by **airstreamliving** » Sat Oct 08, 2005 10:59 pm

NeddySeagoon wrote:airstreamliving,

DrWoland said 300 Megabytes

Yeah, I noticed that too, but figured he made a type-o after seeing the links he provided showing 300 Gig drives.

You'd be hard-pressed to find a 300 meg drive these days, though in my closet I still have a 280 Meg hard drive I'd be willing to part with for $89...

DrWoland · Post by **DrWoland** » Sun Oct 09, 2005 12:15 am

Wow I did say 300 MB... that puts a few things said in this thread in quite a different light

It's 300 GB, and running off an iPod sounds pretty effin cool.

DrWoland · Post by **DrWoland** » Fri Oct 14, 2005 2:28 am

Mr Wonka wrote:I've just got this setup running on my External USB 2 harddrive. Theres a couple of issues I encountered but nothing drastic and other then those it's a straight Gentoo install.

1. Some USB drive take a while to come up. You can't rely on the kernel having access to them when it attempts to mount the root filesystem. To solve this just pass 'rootdelay=X' where X is a number of seconds. I've found 10 to work just fine seeing as my drive takes between 4 and 7 seconds to appear.

2. Grub sees my drives in a different way to the kernel. It seems to swap them over. i.e. sda = hd0 and hda = hd1. This isn't a major stumbling block though. Just make sure to watch where you put that bootloader!

Oh, and none of this will work unless your computers support USB booting.

Hope this helps.

You really are a lifesaver. #1 definitely happened and I forgot about this post at first. Took me a while to finally put it in. Installing Xorg now