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Gentree
Watchman
Joined: 01 Jul 2003
Posts: 5350
Location: France, Old Europe
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 Posted: Sun Sep 12, 2010 2:40 am Post subject: grub can't see sata drive at boot time [SOLVED] |
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Hi,
I have a working installation but since this a grub issue I suppose it's best posted here.
This machine has one ide drive and one sata. Currently bios boots to the ide and grub is installed on the mbr of this drive and calls it HD0.
There are many partitions on both drives but this essentials for this question are:
| Code: | /dev/sda11 reiser4 12G 7.5G 4.0G 66% /
/dev/hda3 ext3 54M 49M 2.1M 97% /boot
/dev/sda8 ext3 16G 9.5G 5.5G 64% /home
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So clearly there is no big problem with sda , it holds the current root fs.
If I run grub shell , enter root command and use tab key for autocompletion options it outputs:
| Code: |
grub> root (hd
Possible disks are: hd0 hd1 |
(as a side note I did not enter the hd , it was inserted by grub. It accessed the floppy but did not show it as an option)
If I try the same thing from the boot grub menu I get:
| Code: | grub> root (
Possible disks are: fd0 hd0 |
The BIG problem is that hd1 is no available. I want to clone gentoo to be using boot partition on sda3 and but if I edit grub.conf and select it at boot time it says the disk does not exist !!
This is clearly wrong since grub shell can see it and system is running from that disk if booted from /dev/hda3
Just to be sure it was the exact same version of grub in both instances, I reinstalled grub onto (hd0) :
| Code: | root (hd0,2)
setup (hd0)
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All went well but the result is the same.
So why is there a difference in what grub outputs in the two cases and why can't it find the sata disk from the boot menu despite the fact the kernel loaded from the ide drive has no trouble using it?
TIA, Gentree. 
_________________
Linux, because I'd rather own a free OS than steal one that's not worth paying for.
Gentoo because I'm a masochist
AthlonXP-M on A7N8X. Portage ~x86
Last edited by Gentree on Sun Sep 12, 2010 10:04 am; edited 1 time in total |
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dmpogo
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Joined: 02 Sep 2004
Posts: 3267
Location: Canada
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| Posted: Sun Sep 12, 2010 4:43 am Post subject: |
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Your BIOS did not yet initialized the second drive by the time you get a boot prompt ?
To what mode SATA drive is set in BIOS ? Is it in the list in BIOS of bootable devices ? |
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krinn
Watchman
Joined: 02 May 2003
Posts: 7470
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| Posted: Sun Sep 12, 2010 8:36 am Post subject: |
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Some add-in card don't have a bios to handle drives (can't be cheaper), some bios disable int13 and so additional cards cannot get a chance to load their bios to handle disks they handle.
Check that you see your additional sata card bios while booting, check your bios for int13h option else.
If the addin card for your sata is build-in m/b it should be a mistake in bios option like dmpogo said (enable ahci if your in compatibility mode)
Some poor bios didn't even gave an interrupt to some device when pnp os is set, you can disable the option to force your bios to pickup an interrupt for all devices (lol and some really poor bios will then assign everyone to the 3-4 same interrupts) |
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Gentree
Watchman
Joined: 01 Jul 2003
Posts: 5350
Location: France, Old Europe
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| Posted: Sun Sep 12, 2010 10:04 am Post subject: |
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Thanks for the replies , you were along the right lines.
I found that it was not enough to set bios to boot from sata. I also have to activate the RAID option.
This makes not a lot of sense for one drive but that's the trick.
Now my boot time is even longer while it tries and fails to detect a second drive for the raid but at least I do now get HD1 available to grub at boot time and all the rest works.
In case anyone else hits this , it concerns ASUS a7n8x mobo with on-board Silicon Image SiI 3112 sata controller
Thanks for the help.
_________________
Linux, because I'd rather own a free OS than steal one that's not worth paying for.
Gentoo because I'm a masochist
AthlonXP-M on A7N8X. Portage ~x86 |
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dmpogo
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Joined: 02 Sep 2004
Posts: 3267
Location: Canada
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| Posted: Sun Sep 12, 2010 11:08 pm Post subject: |
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| Gentree wrote: | Thanks for the replies , you were along the right lines.
I found that it was not enough to set bios to boot from sata. I also have to activate the RAID option.
This makes not a lot of sense for one drive but that's the trick.
Now my boot time is even longer while it tries and fails to detect a second drive for the raid but at least I do now get HD1 available to grub at boot time and all the rest works.
In case anyone else hits this , it concerns ASUS a7n8x mobo with on-board Silicon Image SiI 3112 sata controller
Thanks for the help. |
Just AHCI mode was not enough ? |
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Gentree
Watchman
Joined: 01 Jul 2003
Posts: 5350
Location: France, Old Europe
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| Posted: Mon Sep 13, 2010 7:41 am Post subject: |
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The BIOS does not offer "modes".
I have boot device priority: IDE/PCI add-ons
If I set PCI at top priority I can choose whether PCI add-ons uses a PCI card or the on-board sata controller.
The latter is sufficient to get use of the sata drive from the kernel but it is not present for grub at boot time.
As detailed above , I also need to enable RAID feature. During boot the sata bios tries to detect drives for raid , only finds one then gives up. This adds about 4s to boot time , which is a bit annoying.
At this stage the sata drive becomes available to grub.
I think this is probably an oversight in the BIOS design.
There were some clever guys hacking this bios for overclocking and other mods but ASUS have removed the forum where all this stuff was discussed and it's passed into history.
_________________
Linux, because I'd rather own a free OS than steal one that's not worth paying for.
Gentoo because I'm a masochist
AthlonXP-M on A7N8X. Portage ~x86 |
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Installing Gentoo
