From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael H. Warfield" Subject: Re: [Devel] Re: LXC container, unmounting unneeded mount points (from the container namespace) Date: Wed, 13 Jan 2010 09:15:34 -0500 Message-ID: <1263392134.14592.137.camel@localhost> References: <8e04b5821001080608w47b0529dhcd6f8a26e38f24e0@mail.gmail.com> <4B473E89.1040200@free.fr> <8e04b5821001080625j22517f1i22ec3495d8d1e53b@mail.gmail.com> <4B4742A8.1000708@free.fr> <1263268449.14592.53.camel@localhost> <4B4DD076.3090007@free.fr> Reply-To: mhw-BetbSzk+GohWk0Htik3J/w@public.gmane.org Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============0836813159703544108==" Return-path: In-Reply-To: <4B4DD076.3090007-GANU6spQydw@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Mime-version: 1.0 Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Daniel Lezcano Cc: Michael Holzt , mhw-BetbSzk+GohWk0Htik3J/w@public.gmane.org, containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, "Ciprian Dorin, Craciun" , lxc-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: containers.vger.kernel.org --===============0836813159703544108== Content-Type: multipart/signed; micalg="pgp-sha1"; protocol="application/pgp-signature"; boundary="=-vtB0iQ1tjWlEELNPWHbE" --=-vtB0iQ1tjWlEELNPWHbE Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Wed, 2010-01-13 at 14:53 +0100, Daniel Lezcano wrote:=20 > Michael H. Warfield wrote: > > Added lxc-devel to the cc list since this seems to be more appropriate > > over there (maybe) and I've just joined that one as well. > > > > On Fri, 2010-01-08 at 15:35 +0100, Daniel Lezcano wrote:=20 > > =20 > >> Ciprian Dorin, Craciun wrote: > >> =20 > >>> On Fri, Jan 8, 2010 at 4:17 PM, Daniel Lezcano wrote: > >>> =20 > >>> =20 > >>>> Ciprian Dorin, Craciun wrote: > >>>> =20 > >>>> =20 > >>>>> Hy all! > >>>>> > >>>>> Today I've started to play with the LXC containers, and I've got= a > >>>>> question: when starting a container (with it's own mount point > >>>>> namespace), and I do a `cat /proc/mounts` I also see the mount poin= ts > >>>>> from my host system. > >>>>> > >>>>> So the question is: how can I force `lxc-create` to remove any > >>>>> uneeded mount points (maybe all)? > >>>>> > >>>>> =20 > >>>>> =20 > >>>> Committed today :) > >>>> > >>>> http://git.lab.toulouse-stg.fr.ibm.com/?p=3Dlxc.git;a=3Dcommit;h=3De= d83715df7666879116d1657b1dd54a8fc6513f6 > >>>> =20 > >>>> =20 > > > > =20 > >> Oops, this one: > >> =20 > > > > =20 > >> http://lxc.git.sourceforge.net/git/gitweb.cgi?p=3Dlxc/lxc;a=3Dcommit;h= =3Dbf601689a9e0cea1ceaf17e4f7f853f5392c2827 > >> =20 > > > > Nice. This is EXACTLY what I've been looking for as well. Only proble= m > > is... It didn't work. It complains about: > > > > lxc-start: could not umount 1 mounts" > > > > Then terminates saying it can't start the container. > > > > When I throw in some debugging prints, I find out that it's complaining > > that it can't umount {pivotdir}/dev. Commented out the return -1's in > > that routine so it starts the container anyways and jump into the > > running container and I discover that {pivotdir}/dev/shm is still > > mounted even though it thinks it umounted it. I can see from the > > debugging prints that it seems to have successfully umount it (the > > debugging message indicates that it umounted it - so it saw it had it > > and tried and got a good return from the attempt) but it's apparently > > still mount. If I umount that {pivotdir}/dev/shm inside the container, > > I can then umount {pivotdir}/dev and {pivotdir}.=20 > > > > Tried it both by defining lxc.pivotdir and by letting it choose a > > temporary one. Tried two different containers. Same result. > > > > This is what I get with the "return -1"'s commented out in the function > > and laced with my own debugging prints to print each step of the umount > > loop (this is with lxc.pivotdir =3D /rootfs): > > > > =3D=3D=3D > > [root@Berserker-Base ~]# lxc-start -n 1009 > > still mounted '/rootfs/dev' > > umounted '/rootfs/dev/pts' > > umounted '/rootfs/dev/shm' > > still mounted '/rootfs/proc' > > umounted '/rootfs/proc/bus/usb' > > umounted '/rootfs/proc/sys/fs/binfmt_misc' > > umounted '/rootfs/sys' > > umounted '/rootfs/home' > > still mounted '/rootfs/var' > > umounted '/rootfs/var/lib/cgroup' > > umounted '/rootfs/var/lib/nfs/rpc_pipefs' > > umounted '/rootfs/usr' > > umounted '/rootfs/boot' > > still mounted '/rootfs/srv' > > umounted '/rootfs/misc' > > umounted '/rootfs/net' > > still mounted '/rootfs/srv/lxc/root/1009' > > umounted '/rootfs/srv/lxc/root/1009/export' > > umounted '/rootfs/srv/lxc/root/1009/srv/shared' > > umounted '/rootfs/srv/lxc/root/1009/dev/pts' > > umounted '/rootfs/srv/lxc/root/1009/proc' > > umounted '/rootfs/srv/lxc/root/1009/sys' > > umounted '/rootfs/srv/lxc/root/1009/dev/shm' > > umounted '/rootfs/srv/lxc/root/1009/dev/console' > > umounted '/rootfs/srv/lxc/root/1009/dev/tty1' > > umounted '/rootfs/srv/lxc/root/1009/dev/tty2' > > umounted '/rootfs/srv/lxc/root/1009/dev/tty3' > > umounted '/rootfs/srv/lxc/root/1009/dev/tty4' > > umounted '/rootfs/srv/lxc/root/1009/dev/tty5' > > umounted '/rootfs/srv/lxc/root/1009/dev/tty6' > > still mounted '/rootfs/dev' > > umounted '/rootfs/proc' > > umounted '/rootfs/var' > > still mounted '/rootfs/srv' > > umounted '/rootfs/srv/lxc/root/1009' > > still mounted '/rootfs/dev' > > umounted '/rootfs/srv' > > still mounted '/rootfs/dev' > > lxc-start: could not umount 1 mounts > > lxc-start: Device or resource busy - could not unmount old rootfs > > INIT: version 2.86 booting > > =3D=3D=3D > > > > Container now continues to boot, since I commented out the error > > returns. Jumping into that container: > > > > =3D=3D=3D=20 > > [root@Berserker ~]# df > > Filesystem 1K-blocks Used Available Use% Mounted on > > rootfs 288433504 240305660 33476248 88% / > > /dev/sda6 2063504 662116 1296568 34% /rootfs > > udev 1031280 200 1031080 1% /rootfs/dev > > /dev/shm 1031280 0 1031280 0% /rootfs/dev/shm > > /dev/mapper/VolGroup00-LogVol00 > > 288433504 240305660 33476248 88% / > > /dev/sda6 2063504 662116 1296568 34% /export > > /dev/sda7 693727244 554704408 103783460 85% /srv/shared > > none 1031280 0 1031280 0% /dev/shm > > [root@Berserker ~]# umount /rootfs/dev/shm > > [root@Berserker ~]# umount /rootfs/dev =20 > > [root@Berserker ~]# umount /rootfs =20 > > [root@Berserker ~]# df > > Filesystem 1K-blocks Used Available Use% Mounted on > > rootfs 288433504 240305672 33476236 88% / > > /dev/mapper/VolGroup00-LogVol00 > > 288433504 240305672 33476236 88% / > > /dev/sda6 2063504 662116 1296568 34% /export > > /dev/sda7 693727244 554704408 103783460 85% /srv/shared > > none 1031280 0 1031280 0% /dev/shm > > =3D=3D=3D > > > > Of course we also have the strange "rootfs" entry there as well. > > > > Host system is Fedora 12. > > Host kernel is: 2.6.31.9-174.fc12.i686 > > Guest system in each case is CentOS 5.4 > > =20 > I added in the Cc Michael Holzt. > Thanks for reporting this. I should now mention that I've been digging into it further and found that I can not reproduce this on a second, similar, system I'm testing on at this point. It may be a peculiarity of the original system and I'm just getting ready to test on a third as soon as I finish getting it updated. IAC, there should be some way to force the container to start, for diagnostic purposes, in a case like this, without modifying the sources. Having the old root directory still there isn't fatal to run the container, particularly in a test system, even though highly undesirable in a production VM. > -- Daniel Regards, Mike --=20 Michael H. Warfield (AI4NB) | (770) 985-6132 | mhw-BetbSzk+GohWk0Htik3J/w@public.gmane.org /\/\|=3Dmhw=3D|\/\/ | (678) 463-0932 | http://www.wittsend.com= /mhw/ NIC whois: MHW9 | An optimist believes we live in the best of a= ll PGP Key: 0x674627FF | possible worlds. A pessimist is sure of it! --=-vtB0iQ1tjWlEELNPWHbE Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) iQEVAwUAS03VhcDrlnVnRif/AQJEaggA0JmOY/utqHzhyHI2HExPPHX0ScAJFe3H tnxCgFmhCHaynzOO81jbClNsIK+hoVkc8nR1gtkEzH8y73yMdoXiViEmjUXmvFLT XWBYCWaRTH4yMJuePeyobcsCVS5qghaplEg2rk4/lhvMJ+dcS21ytq4zKemaMP47 udaqIydiitDT5yNnTJQNCF+xPY56C+A1DnlO3eMfMMH9pIyub64dUDuM+9kqLVP9 qjJzij3uEHbCmX1Qq4+MVMJqd700QOV6HOxFjmf6jWBR80N8TJy60fJQExBBZAF8 4RC7Ni9Tjzpi+U5sRCIxwU8sjo9dCnhEgGkXSrnGVV+RVwJM4emv1A== =SLol -----END PGP SIGNATURE----- --=-vtB0iQ1tjWlEELNPWHbE-- --===============0836813159703544108== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Containers mailing list Containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org https://lists.linux-foundation.org/mailman/listinfo/containers --===============0836813159703544108==--