Fedora Core rescue and umount /mnt/sysimage

April 20th, 2006

Today, I was trying to resize a logical volume of one of my systems running Fedora Core 5, configured with two LVM volumes (one for the root filesystem and another one for swap) on top of a software RAID-0. Since the volume I wanted to shrink holds the root filesystem, I had to boot from the Fedora Core 5 rescue CD in order to reduce the filesystem (ext2online didn’t allow me to reduce the filesystem on the fly), then reducing the volume itself.

Thus, I booted from the Fedora Core 5 DVD by entering linux rescue at the syslinux prompt, then choosed English for both the system language and keyboard layout. Since I was lazy, and didn’t want to manually set up the RAID disks and search for LVM volumes, I told Anaconda to scan the system for a Linux installation and mount it read-only under /mnt/sysimage.

What I didn’t know is that Anaconda also spawns up /mnt/sysimage/usr/bin/bash as the shell (instead of /bin/bash which is the one I expected), appends /mnt/sysimage/bin:/mnt/sysimage/sbin:\
/mnt/sysimage/usr/bin:/mnt/sysimage/usr/sbin:\
/mnt/usr/X11R6/bin to PATH and appends /mnt/sysimage/lib:/mnt/sysimage/usr/lib to LD_LIBRARY_PATH. So, when I tried to umount /mnt/sysimage it failed with a Device or resource busy error message:

# umount /mnt/sysimage/boot
# umount /mnt/sysimage/dev
# umount /mnt/sysimage/selinux
# umount /mnt/sysimage/sys
# umount /mnt/sysimage/proc
# umount /mnt/sysimage
umount: Device or resource busy

The solution was easy, however:

# exec /bin/bash
# umount /mnt/sysimage
# echo $?
0
Posted in Fedora, Linux | 11 Comments »

11 Responses to “Fedora Core rescue and umount /mnt/sysimage”

  1. kazione Says:
    May 4th, 2006 at 4:49 AM

    I ran into something similar while trying to extend the root (/) partition. I couldn’t get the /mnt/sysimage to unmount. So I ended up booting “linux rescue” from the FC5 CD. Then do NOT mount the file system, instead at the shell prompt do:

    # get the name of the vol group
    lvm vgscan

    # active the vol ie: /dev/Vol files are added)
    lvm vgchange -a y /dev/VolGoup00

    #Check the existing file system for errors:
    e2fsck -f /dev/VolGroup00/LogVol00

    #Resize the root (/) file system:
    resize2fs /dev/VolGroup00/LogVol00

    ref:
    http://fedoranews.org/mediawiki/index.php/Expanding_Linux_Partitions_with_LVM

    http://voidmain.is-a-geek.net/files/misc/expand_root_lv.html

    http://www.redhat.com/archives/taroon-list/2005-October/msg00046.html

  2. Felipe Alfaro Solana Says:
    May 6th, 2006 at 5:13 PM

    Thanks for the additional comments, kazione!

  3. Biedak Says:
    July 6th, 2006 at 1:59 PM

    It was just what I was looking for :-)
    Thanks a lot !!!

  4. Jamin Davis Says:
    December 31st, 2006 at 5:11 AM

    Thanks a lot! Trying to get FC6 installed as a vmware guest, spent half-an-hour recompiling the kernel only for the root fs to run out of space. BTW still needed to ‘umount’ the subdirectories after exec /bin/bash, YMMV. Ta.

  5. routethis.net/blog » Blog Archive » Backups? What backups? Says:
    July 6th, 2007 at 6:04 PM

    [...] As a side note, if you ever need to much with LVM, this page helped me a lot (the first comment to the article): http://felipe-alfaro.org/blog/2006/04/20/fedora-core-rescue-and-umount-mntsysimage/ [...]

  6. Joe Says:
    October 30th, 2008 at 7:03 PM

    Thanks a lot. You are a life saver

  7. Heikki Says:
    December 12th, 2008 at 5:28 PM

    Great, thanks! I used the method provided by kazione on RHEL 4, works perfectly. At first I tried umounting /mnt/sysimage, but I guess there where too many connections to that device already and I didn’t want to take half a day killing all those processes…

  8. ipans Says:
    February 2nd, 2010 at 2:45 PM

    great hints and easy to search. thx a lot.

  9. Javier Coscia Says:
    October 7th, 2010 at 12:47 AM

    Thanks a lot Felipe and Kazione, I was looking for something like this, this solved my problem.

  10. Rusty Grat Says:
    December 14th, 2011 at 2:33 PM

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  11. Willard Mccurren Says:
    January 20th, 2012 at 4:41 PM

    Interesting what you are saying about the cat5 cables I tried this to connect 2 pcs together one running XP Pro and one running Win7 with GB network cards and both show a gb connection with crossover cable but I’ve not used anything to check the actual transfer speed, how can you connect 2 pcs directly with a staight through cable?

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