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So i want to install Ubuntu and im booting from USB. Im new to Ubuntu.

When i click SOMETHING ELSE, it shows 4 partions: the first of 1mb, sda1, unknown free space, second of 100mb sda2 (that i know its system recovery from win7), third is 170gb (win7) sda3, and the last one is like 830gb, i dont know where this came from.... on windows i have them separated.

is this a bug or something? How to install without losing all my data and keeping Win7?

When i try without installing i get to see my 3 partions (170gb, 600gb, 230gb) but not when i try to install.

Edit

ubuntu@ubuntu:~$ sudo gdisk -l /dev/sda

outputs this:

GPT fdisk (gdisk) version 0.8.7  
Partition table scan:
  MBR: MBR only
  BSD: not present
  APM: not present
  GPT: not present


***************************************************************
Found invalid GPT and valid MBR; converting MBR to GPT format
in memory. 
***************************************************************

Disk /dev/sda: 1953525168 sectors, 931.5 GiB
Logical sector size: 512 bytes
Disk identifier (GUID): 2729AEE7-A594-4A07-91DF-96116B581067
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 1953525134
Partitions will be aligned on 8-sector boundaries
Total free space is 2044 sectors (1022.0 KiB)

Number  Start (sector)    End (sector)  Size       Code  Name
   1              63            2047   992.5 KiB   4200  Windows LDM data
   2            2048          206847   100.0 MiB   4200  Windows LDM data
   3          206848       245762047   117.1 GiB   4200  Windows LDM data
   4       245762048      1953523119   814.3 GiB   4200  Windows LDM data

And,

ubuntu@ubuntu:~$ sudo fdisk -l

outputs this:

Disk /dev/sda: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders, total 1953525168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0x13344b63

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1              63        2047         992+  42  SFS
Partition 1 does not start on physical sector boundary.
/dev/sda2   *        2048      206847      102400   42  SFS
/dev/sda3          206848   245762047   122777600   42  SFS
/dev/sda4       245762048  1953523119   853880536   42  SFS
share|improve this question
    
Is there anything special about the 830 GB partition? (extended partion?) Also, is your hard drive a dynamic disk drive (which allows more than 4 partitions)? –  saiarcot895 Mar 22 at 15:36
    
@rusty If he has a UEFI computer, this could contain the bootloader. If so, he should NEVER delete that unless he knows EXACTLY what he is doing. –  Dillmo Mar 22 at 15:46
    
As for your issue, just shrink your last (830gb) partition to make space for Ubuntu. Don't shrink it beyond the amount of space that is used, since it will cause data loss and possibly corruption. Ubuntu itself only needs a small linux-swap partition and its own ext4 partition. If you plan on upgrading, I recommend having a large ext4 /home partition and a smaller ext4 / partition (like 20 GB). Good luck! –  Dillmo Mar 22 at 15:48
    
@Dillmo i do have something like UEFI BIOS (im dont know much about computers...). –  Scanevaro Mar 22 at 15:53
    
@saiarcot895 it seems it allows more than 4 partitions. i dont know where did the 830 partition came from, i have 3 partitions on win7 and only the system one is the one it recognizes –  Scanevaro Mar 22 at 15:55

1 Answer 1

Your disk is set up with the Windows Logical Disk Manager (LDM) system (aka "dynamic disks"), which is a proprietary Microsoft layer atop regular partitions. LDM is conceptually similar to the Linux Logical Volume Manager (LVM), but the two are incompatible formats. In any event, you cannot install Ubuntu on the disk in its current state -- at least, not easily. (It might be possible to cobble something together, but even for a Linux guru, that would be a bit of a challenge.)

The easiest solution is to convert from LDM to a more conventional partitioning setup. Some commercial Windows tools, such as EaseUS Partition Master and Partition Wizard, are supposed to be able to do this losslessly. The tools that come with Windows can do the conversion, too, but only by starting with a clean set of partitions (thus effectively wiping your data). Of course, if you're willing to back up your data and know how to restore your system to bootability upon restoring it, this may be an acceptable solution. (For that matter, I strongly recommend backing up all your data before attempting to convert the disk in any way; although the conversion is likely to be simple, the consequences of a bug, power failure at an inopportune moment, or other problem could be catastrophic.) Some people have reported success with wiping the partition table and then using TestDisk to create a new set of partitions, but I recommend against this because there's no guarantee that the filesystems in an LDM setup will be contiguous, which is an assumption of TestDisk. Thus, TestDisk will work if that assumption is met, but if it's not, you could end up with corrupted filesystems and at least some lost data.

Another option is to buy another disk and install Linux on it. That way, you can leave the Windows LDM configuration alone and let Linux control the new disk.

FWIW, Windows has a habit of converting from a conventional configuration to LDM whenever you create a setup with more than four partitions on a disk. AFAIK, Windows doesn't warn you about what it's doing -- or if it does, the message seems to leave little impression, because I have yet to see anybody ever mention it. Thus, you should never use the standard Windows partitioning tools to add partitions, particularly if you know you'll be exceeding four partitions, unless you're willing to use an LDM setup. (A common newbie mistake is to use Windows to create a partition for Linux prior to running the Linux installer. This often pushes the partition count over four and creates more work to undo this problem.)

share|improve this answer
    
This has come up here and here. –  saiarcot895 Mar 22 at 21:16
    
RodSmith so it's MBR with LDM. ..I am just curious about what SFS stands for; Smart File System, Siebel FS, or something else? (googled it, but confused) –  rusty Mar 23 at 5:58
    
According to win.tue.nl/~aeb/partitions/partition_types-1.html, "SFS" stands for "Secure Filesystem"; however, that's a DOS product. Today, the type-0x42 partition type code is much more likely to hold an LDM configuration. (Note that MBR type codes have sometimes been re-used, either accidentally or intentionally. That's one of MBR's problems that GPT is intended to fix.) fdisk's mapping type-0x42 to "SFS" is arguably a bug in today's fdisk. At the very least, it's a reflection of fdisk's age. –  Rod Smith Mar 23 at 16:06
    
Wiping the partition table is by far the best option for manual partitioning, provided you have a backup and can restore Windows. The Arch Linux wiki seems to have a good guide for partitioning. That's what I used my first time. –  Dillmo Mar 23 at 17:20

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