How to install grub on fakeraid (raid 0) which spans 2 TB?

How to install grub on fakeraid (raid 0) which spans 2 TB?

["André Heynatz"]

I have bought two 1 TB harddisks and one 2 TB harddisk (backup).
I want to use the 1 TB harddisks in a RAID 0 array (Intel ICH8R Fakeraid).

OS: Win XP SP3, Win 7, Ubuntu Linux 9.10 32 Bit

My partition plan 1:

P ntfs  300 GB Windows XP SP3 32 Bit
P ntfs  300 GB Windows 7 32 Bit
E
L swap    2 GB Linux swap
L ext4  250 GB Ubuntu Linux 9.10 (Karmic) 32 Bit
L ntfs 1100 GB data (for data exchange and storage)
L ext4   48 GB spare space for testing of new OSes

I wanted to install Linux, then create the data partition with
Win XP SP3 Disk Management Tool. The Linux install failed
because Ubuntu wanted to install GRUB1 which is not part of
the install CD. I wonder that Ubuntu uses GRUB2 at all at the
moment because the FakeRaid support is still lacking which was
known before release (a severe regression).
However, I *managed* to install GRUB1 manually by following the
steps in:

Ubuntu FakeRaidHowto:
https://help.ubuntu.com/community/FakeRaidHowto

Ubuntu 9.10+fakeraid:
http://ubuntuforums.org/showthread.php?t=1360445

Unfortunately, the Extended Partition had no space, the Ubuntu
graphical installer just arrages so much space as required.
As I need two more partitions, I had to expand the Extended
partition somehow. I booted the Ubuntu Live System and could
extend this partition with gparted.
Then I tried to use the Win XP SP3 Disk Management Tool to create
the data partition. It destroyed the logical partitions so that
GRUB cannot boot anymore!!!
So I made another plan: First finish with NTFS partitions, then
start with Linux ones.

My partition plan 2:

P ntfs  300 GB Windows XP SP3 32 Bit
P ntfs  300 GB Windows 7 32 Bit
P ntfs 1100 GB data (for data exchange and storage)
E
L swap    2 GB Linux swap
L ext4  250 GB Ubuntu Linux 9.10 (Karmic) 32 Bit
L ext4   48 GB spare space for testing of new OSes

The last partition I do not need, but in order to include it with
the Extended partition, I added it as a Linux ext4 partition for now.

I installed Ubuntu 9.10 32 Bit with the graphical installer. As
expected, GRUB install failed. But this time GRUB1 cannot be
installed. Maybe I crossed a capacity border. I heard that 2 TB is
a limit, but I have no more (ok, 2 * 1 TB, should work).

The first part describes my experience with GRUB1. The last part is
devoted to GRUB2.

=======================================================
GRUB1 (version 0.97-29ubuntu59 from Ubuntu 9.10 32 Bit)
=======================================================

root@ubuntu:/# fdisk -l /dev/mapper/isw_bfacafefej_Volume0

Disk /dev/mapper/isw_bfacafefej_Volume0: 2000.4 GB, 2000404348928 bytes
255 heads, 63 sectors/track, 243201 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x4d6d4d6c

                              Device Boot      Start         End      Blocks   Id  System
/dev/mapper/isw_bfacafefej_Volume0p1   *           1       35695   286720056    7  HPFS/NTFS
/dev/mapper/isw_bfacafefej_Volume0p2           35696       71391   286720000    7  HPFS/NTFS
/dev/mapper/isw_bfacafefej_Volume0p3           71391      204958  1072876544    7  HPFS/NTFS
/dev/mapper/isw_bfacafefej_Volume0p4          204959      243201   307186897+   5  Extended
/dev/mapper/isw_bfacafefej_Volume0p5          204959      205230     2184808+  82  Linux swap / Solaris
/dev/mapper/isw_bfacafefej_Volume0p6          205231      237122   256172458+  83  Linux
/dev/mapper/isw_bfacafefej_Volume0p7          237123      243201    48829536   83  Linux

ubuntu@ubuntu:~$ sudo mount --rbind /dev /target/dev
ubuntu@ubuntu:~$ sudo cp /etc/resolv.conf /target/etc/
ubuntu@ubuntu:~$ sudo chroot /target
root@ubuntu:/# mount
/dev/mapper/isw_bfacafefej_Volume06 on / type ext4 (rw,errors=remount-ro)
root@ubuntu:/# apt-get update
[...]
root@ubuntu:/# apt-get install grub
[...]
Unpacking grub (from .../grub_0.97-29ubuntu59_i386.deb) ...
Processing triggers for man-db ...
Setting up grub (0.97-29ubuntu59) ...

root@ubuntu:/# cp /usr/lib/grub/i386-pc/* /boot/grub/

Now create a device map so that GRUB knows how to access the RAID array, i.e. with the text editor vi.

root@ubuntu:/# cat /boot/grub/device.map
(fd0) /dev/fd0
(hd0) /dev/mapper/isw_bfacafefej_Volume0

I have to add --device-map, otherwise GRUB1 mentions "Unknown partition table signature".
GPartEd has no problems with my partition table, so I think it is correct.

root@ubuntu:/# grub --no-curses --device-map=/boot/grub/device.map

grub> find /boot/grub/stage1
find /boot/grub/stage1

Error 15: File not found
grub> device (hd0) /dev/mapper/isw_bfacafefej_Volume0
device (hd0) /dev/mapper/isw_bfacafefej_Volume0
grub> find /boot/grub/stage1
find /boot/grub/stage1

Error 15: File not found

grub> geometry (hd0) 
geometry (hd0)
drive 0x80: C/H/S = 243201/255/63, The number of sectors = -387927552, /dev/mapper/isw_bfacafefej_Volume0
   Partition num: 0,  Filesystem type unknown, partition type 0x7
   Partition num: 1,  Filesystem type unknown, partition type 0x7
   Partition num: 2,  Filesystem type unknown, partition type 0x7

The number of sectors seems to be wrong, it is negative.

See above for fdisk -l output which is ok.

I add the dmesg output for detection of one 1 TB hard disk. I have two HDDs of the
same kind, exactly. Only the serial number differs. I hope I have not passed the
2 TB maximum capacity with this RAID configuration.

[    3.656037] ata1: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
[    3.661669] ata1.00: ATA-8: SAMSUNG HD103SJ, 1AJ100E4, max UDMA/133
[    3.661673] ata1.00: 1953525168 sectors, multi 16: LBA48 NCQ (depth 31/32)
[    3.667390] ata1.00: configured for UDMA/133
[    3.672047] ata8: SATA link down (SStatus 0 SControl 300)
[    3.672076] ata7: SATA link down (SStatus 0 SControl 300)
[    3.680155] scsi 0:0:0:0: Direct-Access     ATA      SAMSUNG HD103SJ  1AJ1 PQ: 0 ANSI: 5
[    3.680299] sd 0:0:0:0: Attached scsi generic sg0 type 0
[    3.680333] sd 0:0:0:0: [sda] 1953525168 512-byte logical blocks: (1.00 TB/931 GiB)
[    3.680368] sd 0:0:0:0: [sda] Write Protect is off
[    3.680370] sd 0:0:0:0: [sda] Mode Sense: 00 3a 00 00
[    3.680388] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[    3.680482]  sda: sda1 sda2 sda3 sda4 < >
[    3.684761] sda: p3 size 2145753088 exceeds device capacity, limited to end of disk
[    3.684788] sda: p4 ignored, start 3292650270 is behind the end of the disk
[    3.684980] sd 0:0:0:0: [sda] Attached SCSI disk

======================================================
GRUB2 (version 1.97+20091130 from Ubuntu 10.04 32 Bit)
======================================================

I removed package grub and deleted /boot/grub. Then I downloaded
the new GRUB2 packages from a Ubuntu 10.04 (Lucid) repository.

Further steps:

root@ubuntu:/# ls -1 /data/sysadmin/ubuntu/raid/grub2
grub-common_1.97+20091130-1ubuntu1_i386.deb
grub-pc_1.97+20091130-1ubuntu1_i386.deb

root@ubuntu:/# dpkg -EGi /data/sysadmin/ubuntu/raid/grub2/grub-*
Selecting previously deselected package grub-common.
(Reading database ... 120103 files and directories currently installed.)
Unpacking grub-common (from .../grub-common_1.97+20091130-1ubuntu1_i386.deb) ...
Selecting previously deselected package grub-pc.
Unpacking grub-pc (from .../grub-pc_1.97+20091130-1ubuntu1_i386.deb) ...
Setting up grub-common (1.97+20091130-1ubuntu1) ...

Processing triggers for man-db ...
Processing triggers for install-info ...
Processing triggers for sreadahead ...
Setting up grub-pc (1.97+20091130-1ubuntu1) ...

Creating config file /etc/default/grub with new version

root@ubuntu:/# update-grub
Generating grub.cfg ...
Found linux image: /boot/vmlinuz-2.6.31-14-generic
Found initrd image: /boot/initrd.img-2.6.31-14-generic
Found memtest86+ image: /boot/memtest86+.bin
Found Windows 7 (loader) on /dev/mapper/isw_bfacafefej_Volume01
Found Windows 7 (loader) on /dev/mapper/isw_bfacafefej_Volume0p1
Found Ubuntu 9.10 (9.10) on /dev/mapper/isw_bfacafefej_Volume0p6
done

root@ubuntu:/# grub-install /dev/mapper/isw_bfacafefej_Volume0
Installation finished. No error reported.

Reboot.

GRUB loading.
error: no such disk
grub rescue>

Even after correcting /boot/grub/device.map to the dmraid configuration
(see GRUB1 section), I still cannot boot and get the
error message above. 

Here is my /boot/grub/grub.cfg:

#
# DO NOT EDIT THIS FILE
#
# It is automatically generated by /usr/sbin/grub-mkconfig using templates
# from /etc/grub.d and settings from /etc/default/grub
#

### BEGIN /etc/grub.d/00_header ###
if [ -s $prefix/grubenv ]; then
  set have_grubenv=true
  load_env
fi
set default="0"
if [ ${prev_saved_entry} ]; then
  set saved_entry=${prev_saved_entry}
  save_env saved_entry
  set prev_saved_entry=
  save_env prev_saved_entry
fi
insmod ext2
set root=(/dev/mapper/isw_bfacafefej_Volume06)
search --no-floppy --fs-uuid --set 9f8c8d2f-0f67-454c-aec0-affd8fa02fe9
if loadfont /usr/share/grub/unicode.pf2 ; then
  set gfxmode=640x480
  insmod gfxterm
  insmod vbe
  if terminal_output gfxterm ; then true ; else
    # For backward compatibility with versions of terminal.mod that don't
    # understand terminal_output
    terminal gfxterm
  fi
fi
set locale_dir=/boot/grub/locale
set lang=en
insmod gettext 
if [ ${recordfail} = 1 ]; then
  set timeout=-1
else
  set timeout=10
fi
### END /etc/grub.d/00_header ###

### BEGIN /etc/grub.d/05_debian_theme ###
set menu_color_normal=white/black
set menu_color_highlight=black/white
### END /etc/grub.d/05_debian_theme ###
### BEGIN /etc/grub.d/10_linux ###
menuentry "Ubuntu, with Linux 2.6.31-14-generic" {
        set recordfail=1
        if [ -n ${have_grubenv} ]; then save_env recordfail; fi
        set quiet=1
        insmod ext2
        set root=(/dev/mapper/isw_bfacafefej_Volume06)
        search --no-floppy --fs-uuid --set 9f8c8d2f-0f67-454c-aec0-affd8fa02fe9
        linux   /boot/vmlinuz-2.6.31-14-generic root=UUID=9f8c8d2f-0f67-454c-aec0-affd8fa02fe9 ro   quiet splash
        initrd  /boot/initrd.img-2.6.31-14-generic
}
menuentry "Ubuntu, with Linux 2.6.31-14-generic (recovery mode)" {
        set recordfail=1
        if [ -n ${have_grubenv} ]; then save_env recordfail; fi
        insmod ext2
        set root=(/dev/mapper/isw_bfacafefej_Volume06)
        search --no-floppy --fs-uuid --set 9f8c8d2f-0f67-454c-aec0-affd8fa02fe9
        linux   /boot/vmlinuz-2.6.31-14-generic root=UUID=9f8c8d2f-0f67-454c-aec0-affd8fa02fe9 ro single 
        initrd  /boot/initrd.img-2.6.31-14-generic
}
### END /etc/grub.d/10_linux ###

### BEGIN /etc/grub.d/20_memtest86+ ###
menuentry "Memory test (memtest86+)" {
        linux16 /boot/memtest86+.bin
}
menuentry "Memory test (memtest86+, serial console 115200)" {
        linux16 /boot/memtest86+.bin console=ttyS0,115200n8
}
### END /etc/grub.d/20_memtest86+ ###

### BEGIN /etc/grub.d/30_os-prober ###
menuentry "Windows 7 (loader) (on /dev/mapper/isw_bfacafefej_Volume01)" {
        insmod ntfs
        set root=(/dev/mapper/isw_bfacafefej_Volume01)
        search --no-floppy --fs-uuid --set 022834062833f6ef
        chainloader +1
}
### END /etc/grub.d/30_os-prober ###

### BEGIN /etc/grub.d/40_custom ###
# This file provides an easy way to add custom menu entries.  Simply type the
# menu entries you want to add after this comment.  Be careful not to change
# the 'exec tail' line above.
### END /etc/grub.d/40_custom ###

=======================================================================

What can I do now?

Andre

-- 
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http://portal.gmx.net/de/go/dsl02

Re: How to install grub on fakeraid (raid 0) which spans 2 TB?

[Felix Zielcke]

Am Dienstag, den 22.12.2009, 18:02 +0100 schrieb "André Heynatz":
> I have bought two 1 TB harddisks and one 2 TB harddisk (backup).
> I want to use the 1 TB harddisks in a RAID 0 array (Intel ICH8R
> Fakeraid).
> 

> I wanted to install Linux, then create the data partition with
> Win XP SP3 Disk Management Tool. The Linux install failed
> because Ubuntu wanted to install GRUB1 which is not part of
> the install CD. 

There was a bug that GRUB Legacy wasn't included on the karmic DVD but
that should have been fixed already. So make sure you use a fresh image
file.

> I wonder that Ubuntu uses GRUB2 at all at the
> moment because the FakeRaid support is still lacking which was
> known before release (a severe regression).

That's why grub-installer uses still GRUB Legacy in case /boot is on a
dmraid.


GRUB Legacy is complete dead for us, so if you want to have help for
that you have to ask at some Ubuntu place or somewhere else.
With GRUB 2 you could try the lucid (10.04) package out.
At least grub-probe should work there.
But I never tested if grub-setup works and so not if it actually boots
correctly from a dmraid.

-- 
Felix Zielcke
Proud Debian Maintainer and GNU GRUB developer

Re: How to install grub on fakeraid (raid 0) which spans 2 TB?

["André Heynatz"]

-------- Original-Nachricht --------
> Datum: Tue, 22 Dec 2009 18:24:20 +0100
> Von: Felix Zielcke <fzielcke@z-51.de>
> An: The development of GNU GRUB <grub-devel@gnu.org>
> Betreff: Re: How to install grub on fakeraid (raid 0) which spans 2 TB?

> Am Dienstag, den 22.12.2009, 18:02 +0100 schrieb "André Heynatz":
> > I have bought two 1 TB harddisks and one 2 TB harddisk (backup).
> > I want to use the 1 TB harddisks in a RAID 0 array (Intel ICH8R
> > Fakeraid).
> > 
> 
> > I wanted to install Linux, then create the data partition with
> > Win XP SP3 Disk Management Tool. The Linux install failed
> > because Ubuntu wanted to install GRUB1 which is not part of
> > the install CD. 
> 
> There was a bug that GRUB Legacy wasn't included on the karmic DVD but
> that should have been fixed already. So make sure you use a fresh image
> file.
> 
> > I wonder that Ubuntu uses GRUB2 at all at the
> > moment because the FakeRaid support is still lacking which was
> > known before release (a severe regression).
> 
> That's why grub-installer uses still GRUB Legacy in case /boot is on a
> dmraid.
> 
> 
> GRUB Legacy is complete dead for us, so if you want to have help for
> that you have to ask at some Ubuntu place or somewhere else.
> With GRUB 2 you could try the lucid (10.04) package out.
> At least grub-probe should work there.
> But I never tested if grub-setup works and so not if it actually boots
> correctly from a dmraid.
> 
> -- 
> Felix Zielcke
> Proud Debian Maintainer and GNU GRUB developer

I know my initial mail is very long. Please read it completely. At first I have tried GRUB1, then I have tried GRUB2 with the Lucid package - no success yet. The autodetection of operating systems is better in GRUB2, so I would prefer to use the new version. But it does not work even though dmraid is recognized. The configuration seems to be ok, but I cannot boot.
With GRUB1 I had more success, but not with the partition order I chose because of a bug in the Windows XP SP3 Disk Management Tool. All details are in my post.

Thanks for your help,

André

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Re: How to install grub on fakeraid (raid 0) which spans 2 TB?

[Bruce Dubbs]

André Heynatz wrote:
> I have bought two 1 TB harddisks and one 2 TB harddisk (backup).
> I want to use the 1 TB harddisks in a RAID 0 array (Intel ICH8R Fakeraid).
> 
> OS: Win XP SP3, Win 7, Ubuntu Linux 9.10 32 Bit
> 
> My partition plan 1:
> 
> P ntfs  300 GB Windows XP SP3 32 Bit
> P ntfs  300 GB Windows 7 32 Bit
> E
> L swap    2 GB Linux swap
> L ext4  250 GB Ubuntu Linux 9.10 (Karmic) 32 Bit
> L ntfs 1100 GB data (for data exchange and storage)
> L ext4   48 GB spare space for testing of new OSes

I'd suggest:

P ext2  100 MB /boot
P ntfs  300 GB Windows XP SP3 32 Bit
P ntfs  300 GB Windows 7 32 Bit
E
L swap    2 GB Linux swap
L ext4  250 GB Ubuntu Linux 9.10 (Karmic) 32 Bit
L ntfs 1100 GB data (for data exchange and storage)
L ext4   48 GB spare space for testing of new OSes

There is no need for /boot to be on a raid or other 'special' partition 
type.

   -- Bruce

Re: How to install grub on fakeraid (raid 0) which spans 2 TB?

["André Heynatz"]

> André Heynatz wrote:
> > I have bought two 1 TB harddisks and one 2 TB harddisk (backup).
> > I want to use the 1 TB harddisks in a RAID 0 array (Intel ICH8R
> Fakeraid).
> > 
> > OS: Win XP SP3, Win 7, Ubuntu Linux 9.10 32 Bit
> > 
> > My partition plan 1:
> > 
> > P ntfs  300 GB Windows XP SP3 32 Bit
> > P ntfs  300 GB Windows 7 32 Bit
> > E
> > L swap    2 GB Linux swap
> > L ext4  250 GB Ubuntu Linux 9.10 (Karmic) 32 Bit
> > L ntfs 1100 GB data (for data exchange and storage)
> > L ext4   48 GB spare space for testing of new OSes
> 
> I'd suggest:
> 
> P ext2  100 MB /boot
> P ntfs  300 GB Windows XP SP3 32 Bit
> P ntfs  300 GB Windows 7 32 Bit
> E
> L swap    2 GB Linux swap
> L ext4  250 GB Ubuntu Linux 9.10 (Karmic) 32 Bit
> L ntfs 1100 GB data (for data exchange and storage)
> L ext4   48 GB spare space for testing of new OSes
> 
> There is no need for /boot to be on a raid or other 'special' partition 
> type.
> 
>    -- Bruce

Hello Bruce,

thanks for the suggestion. But in order to do this I would need to remove the perfectly working Windows XP and Windows 7 systems to do this which would be a pity. I feel that Linux just CAN do it with Fakeraid, only a tiny bit of work is needed for support. I managed to install Linux on Fakeraid three years ago, with a complicated procedure. It worked like a charm, until I needed more capacity. This time it is a little bit more difficult to get to a solution. I do not care if it is GRUB1 or GRUB2, it should work with both because we are at a turning point and cannot neglect the fact that we need a transition period. I assume that GRUB is to serve users well of course.
My only explanation for the failure of GRUB1 the second time is that there is some overflow happening because of the huge sector counts. If a sector count is stored in a 32 Bit Integer (int), there may be a problem if the sector count exceeds 0x7fffffff, which is 1 TB. My first partition plan lets GRUB use a sector count below 0x80000000, my second partition plan lets the Linux system partition be at a sector address definitely above 0x7fffffff, which may overflow. In general, signedness should be cared about. But in this case it would be even better to use a 64 Bit sector address to accomodate for LBA48 (or LBA64?). Hard disk sizes can only increase, and I read about people using RAID-5 with 6 TB capacity and needing to go to GUID partition tables (GPT) because one partition is to be larger than 2 TB. Windows Vista and Windows 7 support this EFI feature. I am sure Linux does it too, at least Ubuntu Linux which I use has UIDs even in the GRUB1 configuration (probably patched).
I return to partition plan 1 and create the whole partition table with Windows 7 which should be recent enough to handle the size of the disks. The newest Intel Matrix driver should work flawlessly. Afterwards I install Ubuntu Linux near the other system partitions which was my original plan. Especially Windows XP 32 Bit is unsupported in this area (by intent) so I should not depend on it to deal with a partition table. Firstable I try Ubuntu 10.04 GRUB2, then if it does not work I try Ubuntu 9.10 GRUB1 (most recent update).

My old computer without RAID uses GRUB2, and it works flawlessly. Keep up the good work! There will always be special cases which need some attention. We get closer to a "just works" system which would attract many new users. It is not the design which sells systems, maybe later it is, but now it still is the lacking functionality or compatibility which drives users away.

I wish you all a Merry Christmas!

Greetings,

André

-- 
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Re: How to install grub on fakeraid (raid 0) which spans 2 TB?

[Bruce Dubbs]

André Heynatz wrote:
>> André Heynatz wrote:
>>> I have bought two 1 TB harddisks and one 2 TB harddisk (backup). 
>>> I want to use the 1 TB harddisks in a RAID 0 array (Intel ICH8R

>>> P ntfs  300 GB Windows XP SP3 32 Bit P ntfs  300 GB Windows 7 32
>>> Bit E L swap    2 GB Linux swap L ext4  250 GB Ubuntu Linux 9.10
>>> (Karmic) 32 Bit L ntfs 1100 GB data (for data exchange and
>>> storage) L ext4   48 GB spare space for testing of new OSes
>> I'd suggest:
>> 
>> P ext2  100 MB /boot P ntfs  300 GB Windows XP SP3 32 Bit P ntfs
>> 300 GB Windows 7 32 Bit E L swap    2 GB Linux swap L ext4  250 GB
>> Ubuntu Linux 9.10 (Karmic) 32 Bit L ntfs 1100 GB data (for data
>> exchange and storage) L ext4   48 GB spare space for testing of new
>> OSes
>> 
>> There is no need for /boot to be on a raid or other 'special'
>> partition type.
>> 
>> -- Bruce
> 
> Hello Bruce,
> 
> thanks for the suggestion. But in order to do this I would need to
> remove the perfectly working Windows XP and Windows 7 systems to do
> this which would be a pity. 

No, not really.  From your post I thought you you were working with a 
blank HD.  Try this:

P ntfs  300 GB Windows XP SP3 32 Bit
P ntfs  300 GB Windows 7 32 Bit
P ext2  100 MB /boot
E
L swap    2 GB Linux swap
L ext4  250 GB Ubuntu Linux 9.10 (Karmic) 32 Bit
L ntfs 1100 GB data (for data exchange and storage)
L ext4   48 GB spare space for testing of new OSes

I like to use the first partition as /boot, but there is no requirement 
to do that.  I think you can use a logical partition too, but I'm not 
100% sure.

GRUB normally uses a BIOS call as a part of its internal process.  The 
extended call is defined for up to 2^48 sectors.  That is far larger 
than any disk available today.  Any limitation, if it exists, is in the 
BIOS.

> I feel that Linux just CAN do it with
> Fakeraid, only a tiny bit of work is needed for support. I managed to
> install Linux on Fakeraid three years ago, with a complicated
> procedure. It worked like a charm, until I needed more capacity. This
> time it is a little bit more difficult to get to a solution. I do not
> care if it is GRUB1 or GRUB2, it should work with both because we are
> at a turning point and cannot neglect the fact that we need a
> transition period. I assume that GRUB is to serve users well of
> course. 

That's your choice of course.  I haven't worked with any SW raid.  I've 
always thought that HW raid was a better choice.  After all, the value 
of your data is far greater than any raid device.

   -- Bruce

Re: How to install grub on fakeraid (raid 0) which spans 2 TB?

[Seth Goldberg]

>> Hello Bruce,
>> 
>> thanks for the suggestion. But in order to do this I would need to
>> remove the perfectly working Windows XP and Windows 7 systems to do
>> this which would be a pity. 
>
> No, not really.  From your post I thought you you were working with a blank 
> HD.  Try this:
>
> P ntfs  300 GB Windows XP SP3 32 Bit
> P ntfs  300 GB Windows 7 32 Bit
> P ext2  100 MB /boot
> E
> L swap    2 GB Linux swap
> L ext4  250 GB Ubuntu Linux 9.10 (Karmic) 32 Bit
> L ntfs 1100 GB data (for data exchange and storage)
> L ext4   48 GB spare space for testing of new OSes
>
> I like to use the first partition as /boot, but there is no requirement to do 
> that.  I think you can use a logical partition too, but I'm not 100% sure.
>
> GRUB normally uses a BIOS call as a part of its internal process.  The 
> extended call is defined for up to 2^48 sectors.  That is far larger than any 
> disk available today.  Any limitation, if it exists, is in the BIOS.

  While the BIOS call supports 48-bit LBA, the MBR partition table is limited 
to 32-bit LBA addresses for partition dimensions.  If you partition the disk 
with a GPT partition table, those limitations are removed, but GPT-partitioned 
disks aren't supported by XP (at least).

  --S

Re: How to install grub on fakeraid (raid 0) which spans 2 TB?

["André Heynatz"]

> P ntfs  300 GB Windows XP SP3 32 Bit
> P ntfs  300 GB Windows 7 32 Bit
> P ext2  100 MB /boot
> E
> L swap    2 GB Linux swap
> L ext4  250 GB Ubuntu Linux 9.10 (Karmic) 32 Bit
> L ntfs 1100 GB data (for data exchange and storage)
> L ext4   48 GB spare space for testing of new OSes
> 
> I like to use the first partition as /boot, but there is no requirement 
> to do that.  I think you can use a logical partition too, but I'm not 
> 100% sure.
> 
> GRUB normally uses a BIOS call as a part of its internal process.  The 
> extended call is defined for up to 2^48 sectors.  That is far larger 
> than any disk available today.  Any limitation, if it exists, is in the 
> BIOS.
> 

I have applied the partition table mentioned above. Windows 7 Disk Management Tool does not allow to create an Extended Partition on the third Primary partition slot. Thus I used the Ubuntu installer to do it. At first I tried to install GRUB2 from Ubuntu 10.10 (Lucid), but the error message remains :-( Then I tried GRUB1 and succeeded, luckily. Probably there is a problem with the sector offset or the data partition is too large for GRUB1 to skip over. It is > 1 TB. In the actual scheme, the 1.1 TB data partition comes after the root partition (where GRUB is installed).

After a kernel update I have to call 'update-grub' manually, but I am happily doing this, it is only a minor glitch of Ubuntu 9.10.

If there is a new version of GRUB2 which supports dmraid devices, I happily test it. Maybe it is only a configuration issue, as GRUB2 has become quite flexible.

Now I know very well how to restore the GRUB bootloader, I have had much practise.

Of course I will do a backup from my RAID0 system soon.

The system is very fast. No need to wait for boot and shutdown anymore :-)


-- 
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Re: How to install grub on fakeraid (raid 0) which spans 2 TB?

[Bruce Dubbs]

Seth Goldberg wrote:

> While the BIOS call supports 48-bit LBA, the MBR partition table is 
> limited to 32-bit LBA addresses for partition dimensions.  If you 
> partition the disk with a GPT partition table, those limitations are 
> removed, but GPT-partitioned disks aren't supported by XP (at least).

Excellent point, but doesn't that mean a BIOS that supports LBA (which 
as been around for many years) will support 2^18 TB?  I think my 
arithmetic is correct, but please correct me if I misunderstand.

   -- Bruce

Re: How to install grub on fakeraid (raid 0) which spans 2 TB?

[Bruce Dubbs]

André Heynatz wrote:
>> P ntfs  300 GB Windows XP SP3 32 Bit
>> P ntfs  300 GB Windows 7 32 Bit
>> P ext2  100 MB /boot
>> E
>> L swap    2 GB Linux swap
>> L ext4  250 GB Ubuntu Linux 9.10 (Karmic) 32 Bit
>> L ntfs 1100 GB data (for data exchange and storage)
>> L ext4   48 GB spare space for testing of new OSes

> I have applied the partition table mentioned above. Windows 7 Disk
Management Tool does not allow to create an Extended Partition on the
third Primary partition slot. Thus I used the Ubuntu installer to do it.
At first I tried to install GRUB2 from Ubuntu 10.10 (Lucid), but the
error message remains :-( Then I tried GRUB1 and succeeded, luckily.
Probably there is a problem with the sector offset or the data partition
is too large for GRUB1 to skip over. It is > 1 TB. In the actual scheme,
the 1.1 TB data partition comes after the root partition (where GRUB is
installed).

> After a kernel update I have to call 'update-grub' manually, but I am
 > happily doing this, it is only a minor glitch of Ubuntu 9.10.

> If there is a new version of GRUB2 which supports dmraid devices, I
happily test it. Maybe it is only a configuration issue, as GRUB2 has
become quite flexible.

If you would like to test GRUB2 without installing it on the MBR, you 
can do that.  Assuming that your drive is /dev/sda,  you can try:

grub-install --grub-setup=/bin/true /dev/sda

This creates the files needed by your system in /boot/grub.  You can now 
backup your /boot/grub/grub.cfg and try this instead:

### grub.cfg
set default=0
set timeout=15

insmod ext2
set root=(hd0,3)

menuentry "Ubuntu, with Linux 2.6.31-14-generic" {
     search --no-floppy --fs-uuid --set \
               9f8c8d2f-0f67-454c-aec0-affd8fa02fe9
     linux   vmlinuz-2.6.31-14-generic \
                 root=UUID=9f8c8d2f-0f67-454c-aec0-affd8fa02fe9 ro
     initrd  initrd.img-2.6.31-14-generic
}

menuentry "Windows 7 (loader) (on /dev/mapper/isw_bfacafefej_Volume01)"
{
     insmod ntfs
     search --no-floppy --fs-uuid --set 022834062833f6ef
     chainloader +1
}
### end grub.cfg

I took the entries above from your original post.  The continuation 
lines should work, but I haven't tried that.  I didn't want them to wrap 
in this post.  Note that since /boot/grub is a separate partition, we 
omit '/boot' from the start the linux and initrd lines.

Now if you reboot to grub legacy, you can drop to the grub command line:

grub> root (hd0,3)
grub> kernel /grub/core.img
grub> boot

If it works, great.  If not a simple reboot gets you back to grub legacy 
without changing the MBR.

To install GRUB2 on the MBR, just:

   grub-setup /dev/sda

Note that this procedure bypasses the distro setup.  If you update the 
OS automatically, the distro will probably overwrite the grub.cfg file 
when it runs grub-mkconfig, possibly via the grub-pc script.

   -- Bruce

Re: How to install grub on fakeraid (raid 0) which spans 2 TB?

[Seth Goldberg]

On Dec 23, 2009, at 9:37 PM, Bruce Dubbs <bruce.dubbs@gmail.com> wrote:

> Seth Goldberg wrote:
>
>> While the BIOS call supports 48-bit LBA, the MBR partition table is  
>> limited to 32-bit LBA addresses for partition dimensions.  If you  
>> partition the disk with a GPT partition table, those limitations  
>> are removed, but GPT-partitioned disks aren't supported by XP (at  
>> least).
>
> Excellent point, but doesn't that mean a BIOS that supports LBA  
> (which as been around for many years) will support 2^18 TB?  I think  
> my arithmetic is correct, but please correct me if I misunderstand.
>

   Assuming a 512-byte sector size, the total number of bytes is 2^9 *  
2^48 = 2^57 = 2^27 TB.

   --S

>  -- Bruce
>
>
> _______________________________________________
> Grub-devel mailing list
> Grub-devel@gnu.org
> http://lists.gnu.org/mailman/listinfo/grub-devel

Re: How to install grub on fakeraid (raid 0) which spans 2 TB?

[Bruce Dubbs]

Seth Goldberg wrote:
> 
> 
> On Dec 23, 2009, at 9:37 PM, Bruce Dubbs <bruce.dubbs@gmail.com> wrote:
> 
>> Seth Goldberg wrote:
>>
>>> While the BIOS call supports 48-bit LBA, the MBR partition table is 
>>> limited to 32-bit LBA addresses for partition dimensions.  If you 
>>> partition the disk with a GPT partition table, those limitations are 
>>> removed, but GPT-partitioned disks aren't supported by XP (at least).
>>
>> Excellent point, but doesn't that mean a BIOS that supports LBA (which 
>> as been around for many years) will support 2^18 TB?  I think my 
>> arithmetic is correct, but please correct me if I misunderstand.
>>
> 
>   Assuming a 512-byte sector size, the total number of bytes is 2^9 * 
> 2^48 = 2^57 = 2^27 TB.

Hi Seth,

I thought you just said the usual partition table only supported 32 bits:

2^9 * 2^32 = 2^41 bytes or 2 TiB, give or take a byte.  :)

1K = 2^10
1M = 2^20
1G = 2^30
1T = 2^40

I think 48 bits gives 2^17 TiB or 128 Pib (Petabytes).

   -- Bruce

Re: How to install grub on fakeraid (raid 0) which spans 2 TB?

[Seth Goldberg]

Quoting Bruce Dubbs, who wrote the following on Thu, 24 Dec 2009:

> Seth Goldberg wrote:
>> 
>> 
>> On Dec 23, 2009, at 9:37 PM, Bruce Dubbs <bruce.dubbs@gmail.com> wrote:
>> 
>>> Seth Goldberg wrote:
>>> 
>>>> While the BIOS call supports 48-bit LBA, the MBR partition table is 
>>>> limited to 32-bit LBA addresses for partition dimensions.  If you 
>>>> partition the disk with a GPT partition table, those limitations are 
>>>> removed, but GPT-partitioned disks aren't supported by XP (at least).
>>> 
>>> Excellent point, but doesn't that mean a BIOS that supports LBA (which as 
>>> been around for many years) will support 2^18 TB?  I think my arithmetic 
>>> is correct, but please correct me if I misunderstand.
>>> 
>>
>>   Assuming a 512-byte sector size, the total number of bytes is 2^9 * 2^48 
>> = 2^57 = 2^27 TB.
>
> Hi Seth,
>
> I thought you just said the usual partition table only supported 32 bits:
>
> 2^9 * 2^32 = 2^41 bytes or 2 TiB, give or take a byte.  :)
>
> 1K = 2^10
> 1M = 2^20
> 1G = 2^30
> 1T = 2^40
>
> I think 48 bits gives 2^17 TiB or 128 Pib (Petabytes).

   Woops :).  I was calculating the total possible addressable, not the total 
for the DOS partition table :).  Yes, your calculation looks right to me.

  --S

Re: How to install grub on fakeraid (raid 0) which spans 2 TB?

[Vladimir 'φ-coder/phcoder' Serbinenko]

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Seth Goldberg wrote:
>
>
> Quoting Bruce Dubbs, who wrote the following on Thu, 24 Dec 2009:
>
>> Seth Goldberg wrote:
>>>
>>>
>>> On Dec 23, 2009, at 9:37 PM, Bruce Dubbs <bruce.dubbs@gmail.com> wrote:
>>>
>>>> Seth Goldberg wrote:
>>>>
>>>>> While the BIOS call supports 48-bit LBA, the MBR partition table
>>>>> is limited to 32-bit LBA addresses for partition dimensions.  If
>>>>> you partition the disk with a GPT partition table, those
>>>>> limitations are removed, but GPT-partitioned disks aren't
>>>>> supported by XP (at least).
>>>>
>>>> Excellent point, but doesn't that mean a BIOS that supports LBA
>>>> (which as been around for many years) will support 2^18 TB?  I
>>>> think my arithmetic is correct, but please correct me if I
>>>> misunderstand.
>>>>
>>>
>>>   Assuming a 512-byte sector size, the total number of bytes is 2^9
>>> * 2^48 = 2^57 = 2^27 TB.
>>
>> Hi Seth,
>>
>> I thought you just said the usual partition table only supported 32
>> bits:
>>
>> 2^9 * 2^32 = 2^41 bytes or 2 TiB, give or take a byte.  :)
>>
>> 1K = 2^10
>> 1M = 2^20
>> 1G = 2^30
>> 1T = 2^40
>>
>> I think 48 bits gives 2^17 TiB or 128 Pib (Petabytes).
>
>   Woops :).  I was calculating the total possible addressable, not the
> total for the DOS partition table :).  Yes, your calculation looks
> right to me.
>
You assume that BIOS has no limitations other than ones defined by
interfaces. It's a strong assumption and in practice BIOS may have other
problems. GRUB2 supports direct ATA(PI) access but no AHCI yet
>  --S
>
>
> _______________________________________________
> Grub-devel mailing list
> Grub-devel@gnu.org
> http://lists.gnu.org/mailman/listinfo/grub-devel
>


-- 
Regards
Vladimir 'φ-coder/phcoder' Serbinenko



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Re: How to install grub on fakeraid (raid 0) which spans 2 TB?

[Robert Millan]

On Tue, Dec 22, 2009 at 06:02:08PM +0100, "André Heynatz" wrote:
> I wanted to install Linux, then create the data partition with
> Win XP SP3 Disk Management Tool. The Linux install failed
> because Ubuntu wanted to install GRUB1 which is not part of
> the install CD. I wonder that Ubuntu uses GRUB2 at all at the
> moment because the FakeRaid support is still lacking which was
> known before release (a severe regression).
> However, I *managed* to install GRUB1 manually by following the
> steps in:

>2TiB disks on Windows is a no-go.  In theory it'd be possible to support
legacy OSes using a variety of workarounds, but Microsoft, in their
infinite wisdom, added checks in their bootloader and OS kernel with
requirements that are incompatible with each other.  The only disk
layouts that will satisfy both are always limited to 2 TiB.

(Yes, they actually have code in ntldr/bootmgr whose plain removal
would make your setup work)

> What can I do now?

The fix is trivial, but without the Windows source code we don't have
the freedom to help you.  I suggest you get rid of this proprietary OS,
or if that's not possible, install a plain GNU/Linux and use a virtualization
system like KVM or VirtualBox for your legacy compatibility needs.

-- 
Robert Millan

  "Be the change you want to see in the world" -- Gandhi