View Full Version : Windows 7 Ubuntu Dual Boot Installation with existing mounting partitions

December 8th, 2013, 07:00 PM
So I am trying to install ubuntu on my work pc and it says the following:

The installer has detected that the following disks have mounted partitions:

/dev/sda, /dev/sdb

Do you want the installer to try to unmount the partitions on these disks before continuing? If you leave them mounted, you will not be able to create, delete, or resize partitions on these disks, but you may be able to install to existing partitions there

What is my best course of action?

December 8th, 2013, 09:05 PM
I am not sure you should be getting mounted partitions. Is Windows hibernated, is system RAID or some other special configuration?
Post this from the live mode installer.

sudo parted -l
df -h

I do that that same message, but I install from one hard drive to another and the partition with the ISO that I loopmount is mounted. But since I an not doing anything to that drive I do ignore message.

October 24th, 2014, 01:40 PM
No RAID drives. This is the output I get:

ubuntu@ubuntu:~$ sudo parted -l
Model: ATA V4-CT256V4SSD2 (scsi)
Disk /dev/sda: 256GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos

Number Start End Size Type File system Flags
1 1049kB 840MB 839MB primary ntfs boot
2 840MB 249GB 248GB primary ntfs
3 249GB 256GB 6708MB primary ntfs
4 256GB 256GB 110MB primary fat32 diag

Model: ATA WDC WD10EZEX-00R (scsi)
Disk /dev/sdb: 1000GB
Sector size (logical/physical): 512B/4096B
Partition Table: msdos

Number Start End Size Type File system Flags
1 1049kB 1000GB 1000GB primary ntfs

Model: Chipsbnk UDisk (scsi)
Disk /dev/sdc: 1993MB
Sector size (logical/physical): 512B/512B
Partition Table: msdos

Number Start End Size Type File system Flags
1 16.4kB 1993MB 1993MB primary fat32 boot, lba

ubuntu@ubuntu:~$ df -h
Filesystem Size Used Avail Use% Mounted on
/cow 59M 30M 26M 55% /
udev 7.8G 4.0K 7.8G 1% /dev
tmpfs 1.6G 1.3M 1.6G 1% /run
/dev/sdc1 1.9G 1.1G 854M 55% /cdrom
/dev/loop0 939M 939M 0 100% /rofs
none 4.0K 0 4.0K 0% /sys/fs/cgroup
tmpfs 7.9G 1.1M 7.9G 1% /tmp
none 5.0M 0 5.0M 0% /run/lock
none 7.9G 76K 7.9G 1% /run/shm
none 100M 60K 100M 1% /run/user
/dev/loop1 59M 30M 26M 55% /media/ubuntu/casper-rw

October 24th, 2014, 02:24 PM
My current plan:

Create new partitions on /dev/sda for Linux so that I have the following:


This is all new to me, so I have some questions:

Do you think the above partitions are suitable?
Is the install error shown because there are already multiple partitions on /dev/sda?
I will be transferring my projects to Linux so I should free up room on WINDOWS, will I be able to update the partitions in the future without too much hassle?
I read that the LINUX SWAP partition should match the RAM - is that correct?

October 24th, 2014, 03:23 PM
You do have the 4 primary partition limit issue.

Your partition plan is ok, but I prefer smaller system partitions for both Windows & Linux and larger data partition(s). I think what you show for Windows system is just its Boot partition which normally is 100MB. Then you have the main Windows or c: "drive". I would then add another NTFS for data only.

Only if hibernating would you need swap equal to RAM in MiB, not MB. If you have 16GB, then you will not use swap at all. I might have 2 or 3GB just to have some. My 4GB RAM system has not used swap, but it does depend on how much you load into RAM at once. Linux does cache activity so RAM use may grow, but anything not recently used would be released for newer program you start to run.

Is sdb internal or external? If Internal, I would consider installing Ubuntu to that drive.

My laptop already has 4 primary partitions: how can I install Ubuntu?
Good advice on how to handle all four primary partitions used. - srs5694
Be sure to create recovery DVD(s) first. And a Windows repair CD.
HP tools partition discussion - similar for other vendor utility partitions:
For a complete blow-by-blow on dealing with HP's four partitions, see Full Circle Magazine, issue 41, page 36. - gordintoronto

Be sure to fully backup Windows and make a Windows repair CD or flash drive. Most Windows repairs must be done from Windows repair tools.


All Linux and your data partitions can be logical partitions. Windows only requires a primary NTFS partition with the boot flag to boot.

For the Total space you want for Ubuntu:
Ubuntu's standard install is just / (root) & swap, but it is better to add another partition for /home if allocating over 30GB.:
Ubuntu partitions - smaller root only where hard drive space is limited.
If total space less than about 30GB just use / not separate /home or standard install.
1. 10-25 GB Mountpoint / primary or logical beginning ext4
2. all but 2 GB Mountpoint /home logical beginning ext4
3. 2 GB Mountpoint swap logical

Depending on how much memory you have you may not absolutely need swap but having some is still recommended. I do not hibernate (boots fast enough for me) but if hibernating then you need swap equal to RAM in GiB not GB. And if dual booting with windows a shared NTFS partition is also recommended. But you usually cannot create that as part of the install, just leave some space. Or partition in advance (recommended).
One advantage of partitioning in advance is that the installer will use the swap space to speed up the install. Thanks Herman for the tip.

October 24th, 2014, 06:03 PM
You do have the 4 primary partition limit issue.

If Windows lets me I am going to merge partitions #3 and #4 into the #2

Is sdb internal or external? If Internal, I would consider installing Ubuntu to that drive.

It is internal but a very slow drive so I just use it as backup.

Thanks for the info and links - just reading through them now to decide how to partition the hard disks.