yet another request to work around GRUB2

[maxpolaris]

May some kind soul help me please
Old Polack once said

If you install SomeLinux's bootloader to its own / partition, and boot from the PCLinuxOS legacy grub in the MBR, you can chainload to SomeLinux with this stanza placed in the PCLinuxOS /boot/grub/menu.lst

title SomeLinux
root (hdn,n)                               root (1,4)
kernel /boot/grub/core.img  also tried kernel (hd1,4)/boot/grub/core.img
boot

Replace n with the hard drive number, n with the partition number. Both, hard drive and partition counting, start with 0.

I tried this and I get a Error 5 Partition Table invalid or corrupt.
But I have no problems accessing this partition reading writing.
Its an ext4 fs on an extended partition on an external usb hard disk.
/dev/sdb5             223G  2.4G  209G   2% /media/disk  reported by fd on PCLinuxOS
 
                                       Please forgive for me posting all this.
I am very suspicious of this next line which appears in the sdb5 fstab section way below.

# / was on /dev/sdc5 during installation
UUID=cfee47dd-d493-4b9d-bb37-d5e4b045e212 /               ext4    errors=remount-ro 0

If I'm not mistaken UUID cfee47....... is supposed to be my sdb5 I have no idea why / was on
 /dev/sdc5 or what errors=remount-ro 0 mean. I seem to remember when the boot failed with the Error 5 Partition Table invalid or corrupt and was editing in GRUB, after I entered b to boot I got an error like that as well.
                                     Please forgive me for posting it all.
                              Boot Info Script 0.60    from 17 May 2011


============================= Boot Info Summary: ===============================

 => Grub Legacy (v0.97) is installed in the MBR of /dev/sda and looks on the
    same drive in partition #5 for /boot/grub/stage2 and /boot/grub/menu.lst.
 => Grub2 (v1.97-1.98) is installed in the MBR of /dev/sdb and looks at sector
    1 of the same hard drive for core.img. core.img is at this location and
    looks in partition 5 for (,msdos5)/boot/grub.
 => Windows is installed in the MBR of /dev/sdc.
 => Windows is installed in the MBR of /dev/sdd.
 => Syslinux MBR (3.61-4.03) is installed in the MBR of /dev/sde.

sda1: __________________________________________________________________________

    File system:       ntfs
    Boot sector type:  Windows Vista/7
    Boot sector info:   No errors found in the Boot Parameter Block.
    Operating System: 
    Boot files:        /bootmgr /BOOTMGR /boot/bcd /BOOT/bcd /Boot/bcd
                       /boot/BCD /BOOT/BCD /Boot/BCD

sda2: __________________________________________________________________________

    File system:       ntfs
    Boot sector type:  Windows Vista/7
    Boot sector info:   No errors found in the Boot Parameter Block.
    Operating System:  Windows 7
    Boot files:        /Windows/System32/winload.exe

sda3: __________________________________________________________________________

    File system:       Extended Partition
    Boot sector type:  -
    Boot sector info: 

sda5: __________________________________________________________________________

    File system:       ext4
    Boot sector type:  -
    Boot sector info: 
    Operating System:  PCLinuxOS release 2011
                       (PCLinuxOS) for i586 Kernel 2.6.32.12-pclos1.bfs on a
                       Dual-processor i686 /
    Boot files:        /boot/grub/menu.lst /etc/fstab

sda6: __________________________________________________________________________

    File system:       swap
    Boot sector type:  -
    Boot sector info: 

sda7: __________________________________________________________________________

    File system:       ext4
    Boot sector type:  -
    Boot sector info: 
    Operating System: 
    Boot files:       

sda4: __________________________________________________________________________

    File system:       ntfs
    Boot sector type:  Windows Vista/7
    Boot sector info:   No errors found in the Boot Parameter Block.
    Operating System: 
    Boot files:        /bootmgr /BOOTMGR /boot/bcd /BOOT/bcd /Boot/bcd
                       /boot/BCD /BOOT/BCD /Boot/BCD

sdb1: __________________________________________________________________________

    File system:       vfat
    Boot sector type:  FAT32
    Boot sector info:   No errors found in the Boot Parameter Block.
    Operating System: 
    Boot files:       

sdb2: __________________________________________________________________________

    File system:       ext3
    Boot sector type:  -
    Boot sector info: 
    Operating System: 
    Boot files:       

sdb3: __________________________________________________________________________

    File system:       Extended Partition
    Boot sector type:  Unknown
    Boot sector info: 

sdb5: __________________________________________________________________________

    File system:       ext4
    Boot sector type:  -
    Boot sector info: 
    Operating System:  Linux Mint 10 Julia
    Boot files:        /boot/grub/grub.cfg /etc/fstab /boot/grub/core.img

sdb6: __________________________________________________________________________

    File system:       swap
    Boot sector type:  -
    Boot sector info: 

sdc1: __________________________________________________________________________

    File system:       ntfs
    Boot sector type:  Windows Vista/7
    Boot sector info:   No errors found in the Boot Parameter Block.
    Operating System: 
    Boot files:       

sdc2: __________________________________________________________________________

    File system:       ext3
    Boot sector type:  -
    Boot sector info: 
    Operating System: 
    Boot files:       

sdc3: __________________________________________________________________________

    File system:       ext3
    Boot sector type:  -
    Boot sector info: 
    Operating System: 
    Boot files:       

sdc4: __________________________________________________________________________

    File system:       Extended Partition
    Boot sector type:  Unknown
    Boot sector info: 

sdc5: __________________________________________________________________________

    File system:       ext3
    Boot sector type:  -
    Boot sector info: 
    Operating System: 
    Boot files:       

sdc6: __________________________________________________________________________

    File system:       ext3
    Boot sector type:  -
    Boot sector info: 
    Operating System: 
    Boot files:       

sdc7: __________________________________________________________________________

    File system:       ext2
    Boot sector type:  -
    Boot sector info: 
    Operating System: 
    Boot files:       

sdc8: __________________________________________________________________________

    File system:       ext3
    Boot sector type:  -
    Boot sector info: 
    Operating System: 
    Boot files:       

sdc9: __________________________________________________________________________

    File system:       ext3
    Boot sector type:  -
    Boot sector info: 
    Operating System: 
    Boot files:       

sdc10: _________________________________________________________________________

    File system:       ext3
    Boot sector type:  -
    Boot sector info: 
    Operating System: 
    Boot files:       

sdc11: _________________________________________________________________________

    File system:       ext3
    Boot sector type:  -
    Boot sector info: 
    Operating System: 
    Boot files:       

sdc12: _________________________________________________________________________

    File system:       ext3
    Boot sector type:  -
    Boot sector info: 
    Operating System: 
    Boot files:       

sdc13: _________________________________________________________________________

    File system:       swap
    Boot sector type:  -
    Boot sector info: 

sdd1: __________________________________________________________________________

    File system:       ntfs
    Boot sector type:  Windows XP
    Boot sector info:   No errors found in the Boot Parameter Block.
    Operating System: 
    Boot files:       

sde1: __________________________________________________________________________

    File system:       vfat
    Boot sector type:  SYSLINUX 3.73 2009-01-25
    Boot sector info:   Syslinux looks at sector 4000 of /dev/sde1 for its
                       second stage. The integrity check of Syslinux failed.
                       No errors found in the Boot Parameter Block.
    Operating System: 
    Boot files:        /syslinux.cfg /ldlinux.sys

============================ Drive/Partition Info: =============================

Drive: sda _____________________________________________________________________

Disk /dev/sda: 640.1 GB, 640135028736 bytes
255 heads, 63 sectors/track, 77825 cylinders, total 1250263728 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes

Partition  Boot  Start Sector    End Sector  # of Sectors  Id System

/dev/sda1    *          2,048       206,847       204,800   7 NTFS / exFAT / HPFS
/dev/sda2             206,848   642,686,975   642,480,128   7 NTFS / exFAT / HPFS
/dev/sda3         642,696,451 1,227,510,584   584,814,134   5 Extended
/dev/sda5         642,696,453   667,870,244    25,173,792  83 Linux
/dev/sda6         667,870,308   676,047,329     8,177,022  82 Linux swap / Solaris
/dev/sda7         676,047,393 1,227,510,584   551,463,192  83 Linux
/dev/sda4       1,227,511,808 1,250,260,991    22,749,184   7 NTFS / exFAT / HPFS


Drive: sdb _____________________________________________________________________

Disk /dev/sdb: 999.5 GB, 999501594624 bytes
255 heads, 63 sectors/track, 121515 cylinders, total 1952151552 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes

Partition  Boot  Start Sector    End Sector  # of Sectors  Id System

/dev/sdb1               2,048   528,276,099   528,274,052   b W95 FAT32
/dev/sdb2       1,021,814,325 1,952,138,474   930,324,150  83 Linux
/dev/sdb3         528,277,502 1,021,812,735   493,535,234   5 Extended
/dev/sdb5    *    528,277,504 1,001,732,095   473,454,592  83 Linux
/dev/sdb6       1,001,734,144 1,021,812,735    20,078,592  82 Linux swap / Solaris


Drive: sdc _____________________________________________________________________

Disk /dev/sdc: 500.1 GB, 500079525888 bytes
255 heads, 63 sectors/track, 60797 cylinders, total 976717824 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes

Partition  Boot  Start Sector    End Sector  # of Sectors  Id System

/dev/sdc1               2,048   204,802,047   204,800,000   7 NTFS / exFAT / HPFS
/dev/sdc2         204,802,048   243,864,547    39,062,500  83 Linux
/dev/sdc3         243,865,600   645,470,207   401,604,608  83 Linux
/dev/sdc4         645,475,633   976,717,823   331,242,191   5 Extended
/dev/sdc5         645,475,635   665,958,509    20,482,875  83 Linux
/dev/sdc6         665,958,573   706,908,194    40,949,622  83 Linux
/dev/sdc7         706,916,352   727,396,351    20,480,000  83 Linux
/dev/sdc8         727,407,198   768,356,819    40,949,622  83 Linux
/dev/sdc9         768,360,448   818,536,447    50,176,000  83 Linux
/dev/sdc10        818,538,496   868,714,495    50,176,000  83 Linux
/dev/sdc11        868,716,544   918,892,543    50,176,000  83 Linux
/dev/sdc12        918,894,592   969,070,591    50,176,000  83 Linux
/dev/sdc13        969,072,640   976,717,823     7,645,184  82 Linux swap / Solaris


Drive: sdd _____________________________________________________________________

Disk /dev/sdd: 203.9 GB, 203927060480 bytes
255 heads, 63 sectors/track, 24792 cylinders, total 398295040 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes

Partition  Boot  Start Sector    End Sector  # of Sectors  Id System

/dev/sdd1    *             63   398,267,414   398,267,352   7 NTFS / exFAT / HPFS


Drive: sde _____________________________________________________________________

Disk /dev/sde: 1031 MB, 1031798784 bytes
32 heads, 62 sectors/track, 1015 cylinders, total 2015232 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes

Partition  Boot  Start Sector    End Sector  # of Sectors  Id System

/dev/sde1    *             62     2,013,759     2,013,698   b W95 FAT32


"blkid" output: ________________________________________________________________

Device           UUID                                   TYPE       LABEL

/dev/sda1        3E38B42B38B3E057                       ntfs       SYSTEM
/dev/sda2        920CD7B60CD79397                       ntfs       HP
/dev/sda4        866858D06858C11B                       ntfs       FACTORY_IMAGE
/dev/sda5        baafe162-902a-416f-82d5-f8d197ff4e05   ext4       
/dev/sda6        43aa634f-7f17-4fc5-9195-f165d13b8b12   swap       
/dev/sda7        ac63f931-6d35-43cc-877d-0ee81c2ca999   ext4       
/dev/sdb1        9D09-AFD3                              vfat       
/dev/sdb2        fec07e93-717c-409f-8602-79739cd0bddb   ext3       WD476GB
/dev/sdb5        cfee47dd-d493-4b9d-bb37-d5e4b045e212   ext4       MINT
/dev/sdb6        abe8e818-5955-40c2-bfb7-c488d71851e7   swap       
/dev/sdc1        46C07088C070804B                       ntfs       My Passport
/dev/sdc10       7d65237a-ef3c-4a46-a1db-5607f093c3d7   ext3       pp500_e10
/dev/sdc11       62316633-ab5d-4c22-8dba-92776eb96035   ext3       pp500_e11
/dev/sdc12       af21c77d-8c94-4a2a-892e-0439f55cbeb6   ext3       pp500_e12
/dev/sdc13       74b244fa-cf81-4ebc-8198-05ff80dc61f4   swap       swap
/dev/sdc2        b0b97c7b-0a20-4861-8b93-d68cc0a0489c   ext3       pp500_p2
/dev/sdc3        b74faec2-3df5-46dc-b40e-985cd9d081b2   ext3       pp500_p3
/dev/sdc5        5f67e9d8-235b-4ae5-ab52-b43cb1d1efe9   ext3       pp500_e5
/dev/sdc6        6fb892d3-9421-4f25-9de4-1f25dd1b5c78   ext3       pp500_e6
/dev/sdc7        7a6c3b0e-e087-4b1d-a120-6f87d2f82059   ext2       pp500_e7
/dev/sdc8        e3b1daa2-81fc-4b48-adeb-4d2f53ae64a6   ext3       pp500_e8
/dev/sdc9        462d756e-c436-465b-b82d-5cfdb1d75b6f   ext3       pp500_e9
/dev/sdd1        5A704DF5704DD881                       ntfs       Maxtor89G
/dev/sde1        0832-96F2                              vfat       BOOT1G
/dev/sr1                                                udf        WD SmartWare

================================ Mount points: =================================

Device           Mount_Point              Type       Options

/dev/sda5        /                        ext4       (rw)
/dev/sda7        /home                    ext4       (rw,user_xattr)
/dev/sdb5        /media/disk              ext4       (rw,nosuid,nodev,uhelper=hal)


=========================== sda5/boot/grub/menu.lst: ===========================

--------------------------------------------------------------------------------
timeout 60
color black/cyan yellow/cyan
gfxmenu (hd0,4)/boot/gfxmenu
default 0

title linux
kernel (hd0,4)/boot/vmlinuz BOOT_IMAGE=linux root=UUID=baafe162-902a-416f-82d5-f8d197ff4e05  resume=UUID=43aa634f-7f17-4fc5-9195-f165d13b8b12 splash=silent vga=788
initrd (hd0,4)/boot/initrd.img

title linux-nonfb
kernel (hd0,4)/boot/vmlinuz BOOT_IMAGE=linux-nonfb root=UUID=baafe162-902a-416f-82d5-f8d197ff4e05  resume=UUID=43aa634f-7f17-4fc5-9195-f165d13b8b12
initrd (hd0,4)/boot/initrd.img

title failsafe
kernel (hd0,4)/boot/vmlinuz BOOT_IMAGE=failsafe root=UUID=baafe162-902a-416f-82d5-f8d197ff4e05  failsafe
initrd (hd0,4)/boot/initrd.img

title Mint10
root (hd1,4)
kernel /boot/grub/core.img
boot


title windows
root (hd0,0)
makeactive
chainloader +1


sda5/etc/fstab:

--------------------------------------------------------------------------------
# Entry for /dev/sda5 :
UUID=baafe162-902a-416f-82d5-f8d197ff4e05 / ext4 defaults 1 1
# Entry for /dev/sda7 :
UUID=ac63f931-6d35-43cc-877d-0ee81c2ca999 /home ext4 defaults,user_xattr 1 2
none /proc proc defaults 0 0
# Entry for /dev/sda6 :
UUID=43aa634f-7f17-4fc5-9195-f165d13b8b12 swap swap defaults 0 0
none /dev/pts devpts defaults 0 0
tmpfs /dev/shm tmpfs defaults 0 0
--------------------------------------------------------------------------------

=================== sda5: Location of files loaded by Grub: ====================

           GiB - GB             File                                 Fragment(s)

 310.203924656 = 333.078927872  boot/grub/menu.lst                             1
 307.340685368 = 330.004548096  boot/grub/stage2                               1
 313.947710514 = 337.098787328  boot/initrd-2.6.32.12-pclos1.bfs.img           2
 313.947710514 = 337.098787328  boot/initrd.img                                2
 307.242723942 = 329.899362816  boot/initrd.img.old                            1
 308.597307682 = 331.353836032  boot/vmlinuz                                   1
 308.597307682 = 331.353836032  boot/vmlinuz-2.6.32.12-pclos1.bfs              1



sdb5/etc/fstab:

# /etc/fstab: static file system information.
#
# Use 'blkid -o value -s UUID' to print the universally unique identifier
# for a device; this may be used with UUID= as a more robust way to name
# devices that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
proc            /proc           proc    nodev,noexec,nosuid 0       0
# / was on /dev/sdc5 during installation
UUID=cfee47dd-d493-4b9d-bb37-d5e4b045e212 /               ext4    errors=remount-ro 0       1
# swap was on /dev/sda6 during installation
UUID=43aa634f-7f17-4fc5-9195-f165d13b8b12 none            swap    sw              0       0
# swap was on /dev/sdc6 during installation
UUID=abe8e818-5955-40c2-bfb7-c488d71851e7 none            swap    sw              0       0
# swap was on /dev/sdh13 during installation
UUID=74b244fa-cf81-4ebc-8198-05ff80dc61f4 none            swap    sw              0       0
--------------------------------------------------------------------------------

 sdb5: Location of files loaded by Grub

           GiB - GB             File                                 Fragment(s)

 434.039028168 = 466.045857792  boot/grub/core.img                             1
 464.077484131 = 498.299404288  boot/grub/grub.cfg                             1
 464.409603119 = 498.656014336  boot/initrd.img-2.6.35-22-generic-pae          2
 434.034687042 = 466.041196544  boot/vmlinuz-2.6.35-22-generic-pae             1
 464.409603119 = 498.656014336  initrd.img                                     2
 434.034687042 = 466.041196544  vmlinuz                                        1

Unknown MBRs/Boot Sectors/etc:

Unknown BootLoader on sdb3
Unknown BootLoader on sdc4

StdErr Messages:

umount: /tmp/BootInfo2/sdc1: device is busy.
        (In some cases useful info about processes that use
         the device is found by lsof( or fuser(1))
umount: /tmp/BootInfo2/sdd1: device is busy.
        (In some cases useful info about processes that use
         the device is found by lsof( or fuser(1))
  No volume groups found

[djohnston]

I'm surprised you can boot PCLinux at all. Your sda partition table is messed up.

/dev/sda1    *          2,048       206,847       204,800   7 NTFS / exFAT / HPFS
/dev/sda2             206,848   642,686,975   642,480,128   7 NTFS / exFAT / HPFS
/dev/sda3         642,696,451 1,227,510,584   584,814,134   5 Extended
/dev/sda5         642,696,453   667,870,244    25,173,792  83 Linux
/dev/sda6         667,870,308   676,047,329     8,177,022  82 Linux swap / Solaris
/dev/sda7         676,047,393 1,227,510,584   551,463,192  83 Linux
/dev/sda4       1,227,511,808 1,250,260,991    22,749,184   7 NTFS / exFAT / HPFS

sda3 is extended, but you have an sda4. You shouldn't. Your next partitions should be numbered 5 on up. sda4 should be sda8.

Anyway, you need to pass boot control from GRUB legacy to GRUB2 by chainloading. For example,

title GRUB2
root (hd1,4)
chainloader +1

You'll then get the GRUB2 boot menu.

GRUB2 "Error 5" is a disk geometry error. Look at the partition order:

/dev/sdb1               2,048   528,276,099   528,274,052   b W95 FAT32
/dev/sdb2       1,021,814,325 1,952,138,474   930,324,150  83 Linux
/dev/sdb3         528,277,502 1,021,812,735   493,535,234   5 Extended
/dev/sdb5    *    528,277,504 1,001,732,095   473,454,592  83 Linux
/dev/sdb6       1,001,734,144 1,021,812,735    20,078,592  82 Linux swap / Solaris

On the disk, sdb5 and sdb6 precede the starting position of sdb2. Look at the starting sector numbers. You first need to get the disk partitions order corrected on sda and sdb.

[maxpolaris]

djohnston Thanx for the pointers. I'll be looking into all that.

parted shows sda4 as a factory image as far as I know its original.
Maybe I moved a partition.

The sda drive represents my earliest blunderings in resizing and creating partitions to install
linux. I don't know how I got into this mess.

What would you do to try to straighten it out? Anything I should investigate to fix partitions short of reformatting them?

If I can get Somelinux bootable on another drive. Then I'd feel much more comfortable reformatting /resizing partitions on that drive.

Thanx again for the astute observations 

[djohnston]

What would you do to try to straighten it out? Anything I should investigate to fix partitions short of reformatting them?

Old-polack has a lot more experience at this than I do. But here are the basic steps. Backup any irretrievable data on sda and sdb before proceeding. Boot from a PCLinuxOS live CD and make sure no hda and/or hdb partitions are mounted. Open a terminal.

su -
fdisk /dev/sda
x
f
w

The x command will put you in expert mode. The f command will fix the partition order. The w command will write the partition table and exit fdisk. If you want a summary of all possible actions, after entering fdisk /dev/sda, enter m for a menu. (It's already given on the screen.) You'll see x is one of the options. After entering it, enter m again to see the new list of options under expert mode.

Repeat the procedure for drive sdb.

[maxpolaris]

djohnston
                   thank you very much!

After I take care of my disks I'll look further into those chain loading strategies you and Old-Polack offered me.

adios amigos

[kjpetrie]

If you have Grub 2 installed on the MBR of sdb, it isn't on sdb3 [hd(1,4)] but on hd(1)!

If you want to use hd(1,4) in grub you need to install grub 2 to /dev/sdb3.

However, chain loading to a USB device will never be reliable as the device will not necessarily be in the same order each time it is plugged in, as it depends what other USB devices are present.

It makes more sense to set the BIOS to boot from the USB device if plugged in and the HDD otherwise.

[djohnston]

If you want to use hd(1,4) in grub you need to install grub 2 to /dev/sdb3.

However, chain loading to a USB device will never be reliable as the device will not necessarily be in the same order each time it is plugged in, as it depends what other USB devices are present.

Both are good points.

[maxpolaris]

If you have Grub 2 installed on the MBR of sdb, it isn't on sdb3 [hd(1,4)] but on hd(1)!

If you want to use hd(1,4) in grub you need to install grub 2 to /dev/sdb3.

However, chain loading to a USB device will never be reliable as the device will not necessarily be in the same order each time it is plugged in, as it depends what other USB devices are present.

It makes more sense to set the BIOS to boot from the USB device if plugged in and the HDD otherwise.

Yes good point, I was thinking the same thing, asking myself "What if I forget about GRUBing from sda for the moment and start thinking about how I would go about installing independently to a USB Hard Disk that would be set to boot up 1st from BIOS? Should be simpler."  Then in theory I could take my little 500 GB Passport around to different boxes and Plug N Pray.

Then on the other hand I have a 1TB WD that pretty much stays connected to the same box and I could do the same thing just set it 1st in BIOS but I'm gonna figure out how to do it from GRUB on sda just because I know it can be done.

Last couple of days I've been moving and resizing partitions and thinking a bit about separate partitions for / /home /usr /var or the Core System Part, System Variable Part, User Static Part, User Variable Part concept for
security, scalability, ease of back-up and disaster recovery. It's all fun n games.

Thanx for the feedback folks.