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YoMo
Tux's lil' helper
Joined: 01 Jul 2006
Posts: 112
Location: London, UK
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 Posted: Sun Jun 29, 2008 9:56 am Post subject: Full system backup |
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Here is my current disk partitions:
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/dev/hda1
/dev/hda2
/dev/hda3
/dev/hda4 - ext3 (root)
/dev/hda5 - ext2 (boot)
/dev/hda6 - swap
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What I need is to backup hda4 and hda5 because I need to reinstall there gentoo 2008.0 and I would like to keep accessible my old system. So, what I did is to take an external USB drive and partition it in this way (like the gentoo handbook says):
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/dev/sda1 - ext2 (boot)
/dev/sda2 - swap
/dev/sda3 - ext3 (root)
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Then, from a livecd I copied hda4 into sda3 and hda5 into sda1. I added a new entry in grub.conf:
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title=Gentoo Linux 2.6.22-r9
root (hd0,4)
kernel /boot/bzImage-2.6.22-gentoo-r9 root=/dev/hda4 vga=836 video=vesafb:ywrap,mtrr splash=verbose,theme:emergence quiet CONSOLE=/dev/tty1
initrd /boot/fbsplash-emergence-1400x1050
title=Gentoo Linux 2.6.22-r9 (external drive)
root (hd1,0)
kernel (hd1,0)/bzImage-2.6.22-gentoo-r9 root=/dev/sda3 vga=836 video=vesafb:ywrap,mtrr splash=verbose,theme:emergence quiet CONSOLE=/dev/tty1
initrd (hd1,0)/fbsplash-emergence-1400x1050
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Obviously I changed the fstab on /dev/sda3. So, grub takes his config from /dev/hda5 but then boot a kernel residing in /dev/sda1.
Now, I know I did a brutal buckup  so someone can help me to understand why I am getting this error when I boot the external drive grub entry?
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Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
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I am sure the kernel has the support to rw my ext drive, I mount/umount it all the time.
thanks
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Never underestimate the bandwidth of a station wagon full of tapes hurtling down the highway. (Andrew S. Tanenbaum) |
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NeddySeagoon
Administrator
Joined: 05 Jul 2003
Posts: 54805
Location: 56N 3W
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| Posted: Sun Jun 29, 2008 10:07 am Post subject: |
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YoMo,
Mount/Unmount support is not enough to be able to boot from USB.
You need all the USB and SCSI modules built into the kernel, so it can read USB without loading any modules, which will be on the USB drive it needs to load them from.
You also need the kernel paramter rootdelay=<secs> where <secs> is between 10 and 30.
Normally, the kernel mounts root before it starts USB. This is a bad thing if root is on USB.
rootdelay tells the kernel to hold off mounting root and allows USB to get started.
If you have a Gentoo install today, you do not need the 2008.0 release. After
| Code: | emerge --sync
emerge world -uDNav
etc-update
revdep-rebuild |
you have todays Gentoo.
Gentoo does not have releases like binary distros, the 2008.0 refers only to the stage files and installer.
_________________
Regards,
NeddySeagoon
Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail. |
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YoMo
Tux's lil' helper
Joined: 01 Jul 2006
Posts: 112
Location: London, UK
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| Posted: Sun Jun 29, 2008 10:48 am Post subject: |
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Thank you man for the fast reply 
| NeddySeagoon wrote: | YoMo,
Mount/Unmount support is not enough to be able to boot from USB.
You need all the USB and SCSI modules built into the kernel, so it can read USB without loading any modules, which will be on the USB drive it needs to load them from.
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So, in particular, which modules you think I need? When you say all you mean ALL the section Device Drivers->USB support/SCSI device support ? Or you can advise me some entry that for sure I need?
| NeddySeagoon wrote: |
If you have a Gentoo install today, you do not need the 2008.0 release. After
| Code: | emerge --sync
emerge world -uDNav
etc-update
revdep-rebuild |
you have todays Gentoo.
Gentoo does not have releases like binary distros, the 2008.0 refers only to the stage files and installer.
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Yes I know that part, but I want to do it anyway to clean up my system and also to personally teach to a friend 
_________________
Never underestimate the bandwidth of a station wagon full of tapes hurtling down the highway. (Andrew S. Tanenbaum) |
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richard.scott
Veteran
Joined: 19 May 2003
Posts: 1497
Location: Oxfordshire, UK
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| Posted: Sun Jun 29, 2008 11:35 am Post subject: |
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you need to statically include options in:
Device Drivers -> USB Support
You need to include the driver for your USB chipset on the motherboard. I ususally include all the HCD items and also the USB Mass Storage Support option.
And back in this section:
Device Drivers -> SCSI Device Support
activate SCSI disk support and SCSI generic support.
Once you do this your kernel will be able to use the usb interface while its booting. Currently having these options as modules stops this from happening. |
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