usb startup disk failed to unmount /cdrom when change partition tables

[Riobard]

Binary package hint: usb-creator

I created a USB startup disk and booted from it successfully. Then I clicked the "Install" icon to install Ubuntu 8.10. Everything went well: choose a locale, then choose a disk partition. Then a dialog box popped up and said:

"The installer needs to commit changes to partition tables, but cannot do so because partitions on the following mount points could not be unmounted:

/cdrom

Please close any applications using these mount points.

Would you like the installer to try to unmount these partitions again?

[Go Back] [Continue]"

Click either button will bring me back to the "Prepare disk space" step 4/7 stage, and then click Forward will pop up the same dialog box.

I guess the installer needs to modify the partition tables but since /cdrom is mounted by the USB startup disk, it fails to proceed. How do I solve this?

[Evan (ev)]

Can you please run the installer again in debug mode (ubiquity -d from a terminal window) and attach /var/log/syslog, /var/log/partman, and /var/log/installer/debug following the instructions in http://wiki.ubuntu.com/DebuggingUbiquity/AttachingLogs

Thanks

[Riobard (yaogzhan)]

Installation in debug mode succeeded. Please check the log files

[Florian Boucault (fboucault)]

I experienced the same issue when trying to install Ubuntu Jaunty (9.04) from a hard drive partition. I copied the content of the live CD image from http://cdimage.ubuntu.com/daily-live/20081220 a partition of /dev/sda and then booted from it. The exact same dialog box described by Riobard was then shown at the end of the installation configuration process. I was trying to install Ubuntu on a different partition than the one containing the live cd's content obviously.

[rmcd (rmcd1024)]

I encountered the same problem as Riobard. I booted from a USB drive and tried to install, but /cdrom was mounted (same error message as above). I am trying to install to /dev/sdb (which is a new hard disk) but Ubuntu mounts it to /cdrom. I tried but was unable to sudo umount /cdrom before installing (I tried using lsof and fuser to see if there were open files). I ran ubiquity -d but the install did not succeed.

The result is that I am unable to install ubuntu on this machine.

I have attached /var/log/syslog and will send the other requested log files.

[Ronin (dan-todaywasawesome)]

I had the same problem using UNetBootin to create the USB device. I thought that I could tell it not to edit the bootloader and then I would edit it later using a separate install of Ubuntu however the problem persisted.

The problem appears to be with the installer it self. I opened up a terminal to try to manually force unmount the /cdrom mount point it failed even when done as root. It continued to insist that the partition was in use and could not be unmounted.

[ranga27 (sarang-radke)]

I used UNetBootin to extract files from the 9.04 Alpha 3 ISO to my root drive. Could get to the Install menu, but bang... "The dead loop dialog box"

[Iain B (iain-bullard)]

I've just hit what appears to be the same issue, running Jaunty amd64 cdrom copied onto a usb disk using the 'system -> admin -> usb startup disk creator' from a Jaunty install on another system.

Looks like my usb startup disk and my internal disk have both been assigned sda (and my disk has double mount point entries - weird).

ubuntu@ubuntu:~$ df -h
Filesystem Size Used Avail Use% Mounted on
tmpfs 1.9G 2.7M 1.9G 1% /lib/modules/2.6.28-11-generic/volatile
tmpfs 1.9G 2.7M 1.9G 1% /lib/modules/2.6.28-11-generic/volatile
tmpfs 1.9G 0 1.9G 0% /lib/init/rw
varrun 1.9G 100K 1.9G 1% /var/run
varlock 1.9G 0 1.9G 0% /var/lock
udev 1.9G 160K 1.9G 1% /dev
tmpfs 1.9G 580K 1.9G 1% /dev/shm
rootfs 124M 102M 17M 86% /
/dev/sda1 3.9G 825M 3.1G 21% /cdrom
/dev/loop0 674M 674M 0 100% /rofs
tmpfs 124M 102M 17M 86% /tmp
tmpfs 1.9G 2.7M 1.9G 1% /lib/modules/2.6.28-11-generic/volatile
tmpfs 1.9G 2.7M 1.9G 1% /lib/modules/2.6.28-11-generic/volatile
/dev/sda5 5.5G 599M 4.7G 12% /media/disk
/dev/sda7 37G 21G 15G 58% /media/disk-1
/dev/sda1 30G 3.9G 24G 14% /media/disk-2
/dev/sda8 37G 177M 35G 1% /media/disk-3
/dev/sda9 35G 177M 33G 1% /media/disk-4
tmpfs 1.9G 2.7M 1.9G 1% /lib/modules/2.6.28-11-generic/volatile
/dev/sda5 5.5G 599M 4.7G 12% /media/disk
/dev/sda7 37G 21G 15G 58% /media/disk-1
/dev/sda1 30G 3.9G 24G 14% /media/disk-2
/dev/sda8 37G 177M 35G 1% /media/disk-3
/dev/sda9 35G 177M 33G 1% /media/disk-4

It makes sense that we attempt to unmount all the mount points related to a disk before we attempt to alter the partition table. Of course, we need sda1 as its where our live root partition is mounted and thus we enter the 'infinite loop'.

lspci below and dmesg output attached.

ubuntu@ubuntu:~$ lspci
00:00.0 Host bridge: Intel Corporation 4 Series Chipset DRAM Controller (rev 03)
00:03.0 Communication controller: Intel Corporation 4 Series Chipset HECI Controller (rev 03)
00:03.2 IDE interface: Intel Corporation 4 Series Chipset PT IDER Controller (rev 03)
00:03.3 Serial controller: Intel Corporation 4 Series Chipset Serial KT Controller (rev 03)
00:19.0 Ethernet controller: Intel Corporation 82567LM-3 Gigabit Network Connection (rev 02)
00:1a.0 USB Controller: Intel Corporation 82801JD/DO (ICH10 Family) USB UHCI Controller #4 (rev 02)
00:1a.1 USB Controller: Intel Corporation 82801JD/DO (ICH10 Family) USB UHCI Controller #5 (rev 02)
00:1a.2 USB Controller: Intel Corporation 82801JD/DO (ICH10 Family) USB UHCI Controller #6 (rev 02)
00:1a.7 USB Controller: Intel Corporation 82801JD/DO (ICH10 Family) USB2 EHCI Controller #2 (rev 02)
00:1b.0 Audio device: Intel Corporation 82801JD/DO (ICH10 Family) HD Audio Controller (rev 02)
00:1c.0 PCI bridge: Intel Corporation 82801JD/DO (ICH10 Family) PCI Express Port 1 (...

[Iain B (iain-bullard)]

update with resolution and some possibly useful information.

resolution:
Format & recreate usb start up disk. On boot my usb drive was assigned sdb (in fact looking at my dmesg above it was anyway..) upon reboot my df output looked 'normal' (/cdrom was mounted from /dev/sdb1) and the install progressed without issue.

useful information:
This usb disk was initially booted on the same system *without* the hard disk attached, in which case I would have expected the usb disk (/cdrom mount point) to be assigned sda. It seems that with the usb disk this information persists across reboots, at least partially anyway and in some cases can prevent installs from completing (this is my educated guess - I haven't tried to reproduce it a second time).

[Stan Salatov (ksalatov)]

I am getting the exact same error. The only difference here is that I don't have a USB start up disk (old machine - can't boot from a USB) - I run the setup from a Live CD.

[ronan (ronan-l-m)]

I had the same problem. Then I unplugged two of my 3 hard drives (SATA) and the installation had finally succeeded.
Hope it could help some of you.

[J.G. (j.gorski)]

Same problem while trying to unmount /dev/sda7 or /cdrom, where my ubuntu partition is. I would like to partimage that partition from live Ubuntu usb, but no success.

[Xnyper (matt-rixman)]

Seems like the same thing as https://bugs.launchpad.net/ubuntu/+source/base-installer/+bug/313452

If so, the following workaround might be helpful, worked for me:

http://jaredforsyth.com/content/unetbootin-failed-unmount-cdrom

[Florian Boucault (fboucault)]

After following workaround suggested by Xnyper I hit bug #536981

Dirty, unreliable fix was to remount the partition to /cdrom right after hitting the 'install' button of the last step of the installer:

sudo mount -t iso9660 -o ro,noatime /dev/sdaX /cdrom/

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Matteo Pagliazzi (paglia)]

This happens to me when I try to install Ubuntu 12.04 Beta 1 either with a cd or with Unebootin

[Phillip Susi (psusi)]

Are you trying to install to the same disk that you are installing from? Can yout attach your /var/log/syslog when yuo get this error?

[Launchpad Janitor (janitor)]

[Expired for ubiquity (Ubuntu) because there has been no activity for 60 days.]