[bartog]

I have Ubuntu 12.04 64bit full installation running from a 'sandisk cruzer slice' USB 64GB. For Ubuntu I've partitioned 10GB (EXT4). The rest, I want to use with Windows so formatted NTFS. I did the partitioning from within Ubuntu. My computer - Thinkpad x200, 4GB RAM, Win 7pro 32bit - can, and does run 32 & 64 bit Operating Systems.

When i insert the USB while windows in running it asks if I want to format and doesn't recognise the partitioned NTFS space or the EXT4. In fact windows won't recognise the size or contents of the USB at all.

I wanted the USB split into 2 parts so Ubuntu can be run and, when using windows the ability to save files, which is what I mainly want to use the USB for.

Is this because I've mixed 32bit NTFS and 64bit EXT4, even though they're partitioned ?

If not, how can I make windows 7 recognise the NTFS partition on the USB ?

Again, thanks in advance. This is by far the best computer advice site.

[lunarlander]

If you insert the USB and Windows 7 wants to format, then I would just let it do so. Just take care it doesnt format your EXT4 partition. I assume that they have different sizes, so you can recognize which is which inside Windows.

[saikee]

All MS Windows systems treat a USB flash drive as a "giant" floppy and do not expect it has more than one partition. If it does the MS Windows only reads the first partition if it recognises it.

If you do not believe the above do a search!

[bartog]

Yes, Windows only recognizes the first first partition which is where Ubuntu is. It does not see the NTFS partition.
have downloaded 'EaseUS partition master 9.11' and it recognizes both so do i just 'set active' the NTFS part to make it visible in windows ?

[TerryNet]

The way I understand saikee's post is that you need to make the NTFS partition be the first one. You can move partitions (at least on hard drives; never tried on flash drives), but it can be a slow process and, as always, data is at a higher risk during a move.

[saikee]

The active flag is just one byte in the 64-byte partition table. It doesn't help your case at all. Only MS Windows systems use it for booting purpose and the standard MS Windows has not been designed to boot from USB.

MS Windows does not support Linux so you need a driver in Windows to read a Linux partition. In your case the NTFS partition is not the first one so MS Windows will not touch it until you move it to the first partition location.

TerryNet's advice is one of the ways out but it will require you to move the contents of the USB device to a backup storage first, repartition the device to have the NTFS partition as the first partition, move back the data and install Linux in the second partition onward.

[bartog]

I've re-partitioned the USB, NTFS is now first and windows does recognize it. Formatted and installed Ubuntu to the second partition but now when the computer is booted with the USB, it doesn't find Ubuntu and gives the message : NTLDR is missing
Press Ctrl+Alt+Del to restart

Tried F12 on boot but it's a no go.
have the full Ubuntu 12.04 installed but cannot boot it. How do I make my machine see Ubuntu now ?

[saikee]

(1) Boot up the Ubuntu from a Live CD.

(2) Click Application, then Accessories then terminal

(3) Become the super user (or root which is equivalent to Admin in Windows) by command

sudo su

because using system commands require root privileges.

(4) Confirm your USB drive being the device /dev/sdb. Device /dev/sda should be your internal hard disk. /dev/sdb according to your description should have sdb1 type 7 partition for NTFS filing system and your sdb2 should therefore a Linux partition type 83.

(5) If information in Step (4) is correct then restore Grub in the MBR of sdb with commands

mkdir /mnt/sdb2
mount /dev/sdb2 /mnt/sdb2
grub-install --root directory=/mnt/sdb2 /dev/sdb
umount /mnt/sdb2
reboot

The above is first create a mounting point /mnt/sdb2, then mount the device /dev/sdb2 on it, tell Grub this is the root partition and restore Grub in the mbr of /dev/sdb. No number after /dev/sdb means for the whole disk and that is the MBR.

Your USB drive should then boot. My guess is when you install Ubuntu you failed to specify the correct location for the boot loader.

[bartog]

Thanks but I seem to have reached my limit. Got as far as No.3 and from there my brain will not compute. I can't write or understand code. And yes, I probably did choose the wrong place to install the grub loader on the original installation.
I remember a list of 5 or 6 locations being offered and being the dime bar I am, chose the 1st one which I suppose is where NTFS is now located.
If the Terminal screen was a windows like tree then I'd have a chance. It's too much like the old DOS and I was useless with that.

[saikee]

bartog,

In terminal mode you talk directly to the PC.

In Step (4) you issue the following command

sudo fdisk -l

and every partition of every hard disk will be displayed. If you don't know what it means post the output here.

[bartog]

I have Ubuntu running live from an 8GB USB and the 64GB is plugged in so this is showing both the USB's and hard drive.

ubuntu@ubuntu:~$ sudo su
root@ubuntu:/home/ubuntu# sudo fdisk -l

Disk /dev/sda: 160.0 GB, 160041885696 bytes
255 heads, 63 sectors/track, 19457 cylinders, total 312581808 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x88da0d4d

Device Boot Start End Blocks Id System
/dev/sda1 * 2048 206847 102400 7 HPFS/NTFS/exFAT
/dev/sda2 206848 312578047 156185600 7 HPFS/NTFS/exFAT

Disk /dev/sdb: 8036 MB, 8036285952 bytes
255 heads, 63 sectors/track, 977 cylinders, total 15695871 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Device Boot Start End Blocks Id System
/dev/sdb1 * 44 15679439 7839698 b W95 FAT32

Disk /dev/sdc: 64.0 GB, 64016220160 bytes
255 heads, 63 sectors/track, 7782 cylinders, total 125031680 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0005e913

Device Boot Start End Blocks Id System
/dev/sdc1 * 63 102398309 51199123+ 7 HPFS/NTFS/exFAT
/dev/sdc2 102399998 125030399 11315201 5 Extended
/dev/sdc5 102400000 125030399 11315200 83 Linux
root@ubuntu:/home/ubuntu#

[saikee]

Now your "fdisk -l" has shown up 3 disks of 160Gb sda, 8Gb sdb and 64Gb sdc.

Your have only one Linux partition which is sdc5 coloured red below

Device Boot Start End Blocks Id System
/dev/sdb1 * 44 15679439 7839698 b W95 FAT32

Disk /dev/sdc: 64.0 GB, 64016220160 bytes
255 heads, 63 sectors/track, 7782 cylinders, total 125031680 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0005e913

Device Boot Start End Blocks Id System
/dev/sdc1 * 63 102398309 51199123+ 7 HPFS/NTFS/exFAT
/dev/sdc2 102399998 125030399 11315201 5 Extended
/dev/sdc5 102400000 125030399 11315200 83 Linux

Therefore if you want it boot up the commands with a Ubuntu Live CD should be

sudo su
mkdir /mnt/sdc5
mount /dev/sdc5 /mnt/sdc5
grub-install --root directory=/mnt/sdc5 /dev/sdc
umount /mnt/sdc5
reboot

The above will work if the current disk order was exactly how your Ubuntu was installed. This means the 8Gb and the 64Gb USB devices were at the exact ports. If you have changed them since then your Ubuntu may not boot.

The reason is if you did not insert the 8Gb USB device the 64Gb device will inherit the sdb status and would have been installed as the 2nd disk. It has now been detected as sdc means its position is the 3rd disk. There is a 50:50 chance the Ubuntu may boot as Grub2 uses the uuid identification and disregards the disk order.

If the Ubuntu fails to boot you can list the Grub2 configuration file here by

sudo ls /mnt/sdc5/boot/grub/grub.cfg

after you have mounted the partition sdc5.

[bartog]

ubuntu@ubuntu:~$ sudo su
root@ubuntu:/home/ubuntu# mkdir /mnt/sdc5
mkdir: cannot create directory `/mnt/sdc5': File exists
root@ubuntu:/home/ubuntu#

erm, I don't think I cleared the screen first. How do you clear the terminal screen ? Or have I done something else ?

[saikee]

Just continue with the rest of the command.

The error was reported because you might have created /mnt/sdc5 before and the kernel refuses to re-create it again. That is all.

Remember you can use the direction key (arrow point up or down) to call back the previous commands for edit or repeat.

[bartog]

It didn't work. Heres the result plus sudo fdisk l again

ubuntu@ubuntu:~$ sudo su
root@ubuntu:/home/ubuntu# sudo ls /mnt/sdc5/boot/grub/grub.cfg
ls: cannot access /mnt/sdc5/boot/grub/grub.cfg: No such file or directory
root@ubuntu:/home/ubuntu# sudo fdisk -l

Disk /dev/sda: 160.0 GB, 160041885696 bytes
255 heads, 63 sectors/track, 19457 cylinders, total 312581808 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x88da0d4d

Device Boot Start End Blocks Id System
/dev/sda1 * 2048 206847 102400 7 HPFS/NTFS/exFAT
/dev/sda2 206848 312578047 156185600 7 HPFS/NTFS/exFAT

Disk /dev/sdb: 8036 MB, 8036285952 bytes
255 heads, 63 sectors/track, 977 cylinders, total 15695871 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Device Boot Start End Blocks Id System
/dev/sdb1 * 44 15679439 7839698 b W95 FAT32

Disk /dev/sdc: 64.0 GB, 64016220160 bytes
255 heads, 63 sectors/track, 7782 cylinders, total 125031680 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0005e913

Device Boot Start End Blocks Id System
/dev/sdc1 * 63 102398309 51199123+ 7 HPFS/NTFS/exFAT
/dev/sdc2 102399998 125030399 11315201 5 Extended
/dev/sdc5 102400000 125030399 11315200 83 Linux
root@ubuntu:/home/ubuntu#