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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="FONT: 10pt arial; BACKGROUND: #e4e4e4; font-color: black"><B>From:</B>
<A title=silvertip257@gmail.com
href="mailto:silvertip257@gmail.com">SilverTip257</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=centos-virt@centos.org
href="mailto:centos-virt@centos.org">Discussion about the virtualization on
CentOS</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Cc:</B> <A title=jboyce@meridianenv.com
href="mailto:jboyce@meridianenv.com">jboyce@meridianenv.com</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Tuesday, March 05, 2013 4:21
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [CentOS-virt] Need to
unmount an LV from host system</DIV>
<DIV><BR></DIV>
<DIV dir=ltr>On Tue, Mar 5, 2013 at 3:24 PM, <SPAN dir=ltr><<A
href="mailto:jboyce@meridianenv.com"
target=_blank>jboyce@meridianenv.com</A>></SPAN> wrote:<BR>
<DIV class=gmail_extra>
<DIV class=gmail_quote>
<BLOCKQUOTE
style="BORDER-LEFT: #ccc 1px solid; MARGIN: 0px 0px 0px 0.8ex; PADDING-LEFT: 1ex"
class=gmail_quote>Greetings -<BR><BR>Ok, I made a mistake that I need to
fix. Fortunately it is not a<BR>destructive mistake, but I need some
advice on how to correct the problem.<BR><BR>CentOS 6.3 host system named
Earth<BR><BR>I was creating some new logical volumes within my exiting
volume group for<BR>a new virtual machine using the LVM GUI. When I
created the LV that I<BR>plan to use for root partition of the new VM
(Bacteria) I mistakenly<BR>clicked on the box to mount the LV, and specified
the mount point as /.<BR><BR></BLOCKQUOTE>
<DIV><BR></DIV>
<DIV>So you mounted that new LV as / (or over the existing root) on your host
node?</DIV>
<DIV><BR></DIV>
<DIV>You may end up needing to boot to a rescue CD, mount, and rsync files
from Bacteria's root to Earth's [real] root. ( I wonder if anything is
being written to Bacteria's root since it's mounted over the real root.
)</DIV>
<DIV> </DIV>
<BLOCKQUOTE
style="BORDER-LEFT: #ccc 1px solid; MARGIN: 0px 0px 0px 0.8ex; PADDING-LEFT: 1ex"
class=gmail_quote>[root@earth ~]# df -h<BR>Filesystem
Size Used Avail Use% Mounted
on<BR>/dev/mapper/vg_mei-lv_earthroot<BR>
5.0G 3.9G 880M
82% /<BR>tmpfs
5.9G 276K 5.9G 1% /dev/shm<BR>/dev/sda1
485M 116M 344M 26%
/boot<BR>/dev/mapper/vg_mei-lv_earthvar<BR>
3.0G 748M 2.1G
27% /var<BR>/dev/mapper/vg_mei-lv_bacteriaroot<BR>
5.0G 3.9G
880M 82% /<BR><BR>I tried to unmount the device, but as shown
below, it is busy.<BR><BR>[root@earth ~]# umount
/dev/mapper/vg_mei-lv_bacteriaroot<BR>umount: /: device is busy.<BR>
(In some cases useful info about processes that
use<BR> the device is found by lsof(8) or
fuser(1))<BR><BR></BLOCKQUOTE>
<DIV><BR></DIV>
<DIV>I would have expected you could unmount it given that you're umounting by
the device name. Having it mounted on or over root likely makes this a
bit finicky.</DIV>
<DIV> </DIV>
<BLOCKQUOTE
style="BORDER-LEFT: #ccc 1px solid; MARGIN: 0px 0px 0px 0.8ex; PADDING-LEFT: 1ex"
class=gmail_quote>I tried to force unmount the device, but that failed
also.<BR><BR>[root@earth ~]# umount -f
/dev/mapper/vg_mei-lv_bacteriaroot<BR>umount2: Device or resource
busy<BR>umount: /: device is busy.<BR> (In some
cases useful info about processes that use<BR>
the device is found by lsof(8) or fuser(1))<BR>umount2: Device or
resource busy<BR><BR><BR>What other options are there. Is there are
way to get this unmounted<BR>without having to shutdown my host system and
boot into rescue mode. I<BR>don't really want to shutdown my active
VM's while other staff are working<BR>on them right now.<BR></BLOCKQUOTE>
<DIV><BR></DIV>
<DIV>Take the advice of the output you pasted ... check the output from lsof
and see if you can't narrow down the problem.</DIV>
<DIV><BR></DIV>
<DIV>After you accidentally mounted that LV on root did you change your
directory? Something is hanging on to that device.</DIV>
<DIV> </DIV>
<BLOCKQUOTE
style="BORDER-LEFT: #ccc 1px solid; MARGIN: 0px 0px 0px 0.8ex; PADDING-LEFT: 1ex"
class=gmail_quote><BR>Please cc me directly as I only receive the daily
digest. Thanks.<BR><BR>Jeff<BR>Meridian
Environmental<BR><BR><BR>_______________________________________________<BR>CentOS-virt
mailing list<BR><A
href="mailto:CentOS-virt@centos.org">CentOS-virt@centos.org</A><BR><A
href="http://lists.centos.org/mailman/listinfo/centos-virt"
target=_blank>http://lists.centos.org/mailman/listinfo/centos-virt</A><BR></BLOCKQUOTE></DIV><BR
clear=all>
<DIV><BR></DIV>-- <BR>---~~.~~---<BR>Mike<BR>// SilverTip257 //
</DIV>
<DIV class=gmail_extra><FONT face=Arial></FONT> </DIV>
<DIV class=gmail_extra><FONT face=Arial></FONT> </DIV>
<DIV class=gmail_extra><FONT face=Arial>Thanks for the insight. I had
tried the advice from the output to use lsof and fuser, that is what led me to
try the force unmount. In the end I realized that the only way to
unmount a / partition is to be off of it entirely, meaning you must be booted
to a live rescue disk such as SystemRescue CD. I ended up solving this
by checking to make sure that /etc/fstab did not have an entry for the
Bacteria LV, then shutting down the system and rebooting it late at night when
there was no one on the system and no scheduled system activity. A
reboot brought everything back up normal, so I didn't even have to resort to
using a Live CD. Sorry for all the noise.</FONT></DIV>
<DIV class=gmail_extra><FONT face=Arial></FONT> </DIV>
<DIV class=gmail_extra><FONT face=Arial>Jeff</FONT></DIV>
<DIV class=gmail_extra><FONT face=Arial>Meridian Environmental</FONT></DIV>
<DIV class=gmail_extra> </DIV></DIV></BLOCKQUOTE></BODY></HTML>