I'm trying to run same chroots in parallel having the following configuration file stored as /etc/schroot/chroot.d/zz.conf:
[zz]
type=directory
description=Chroot to build CentOS 7: Release
directory=/srv/schroot/vendorname.centos-7
union-type=overlayfs
union-mount-options=lowerdir=/home/builder/build/noarch:/srv/schroot/build.centos-7,upperdir=/home/builder/build/build.centos-7_Release,workdir=/home/builder/build/overlay-work/build.centos-7_Release-build.centos-7
users=builder
groups=users
root-groups=root,wheel
profile=build
preserve-environment=true
Now I use the following command to start 2 sessions:
$ sudo -u builder schroot -c zz -v
entering the first chroot:
I: Executing ‘10mount setup-start ok’
I: 10mount: Mounting /srv/schroot/vendorname.centos-7 on /var/lib/schroot/union/underlay/zz-27fe071c-f7a9-4278-a05e-4003536982f6
I: 10mount: -v --bind /srv/schroot/vendorname.centos-7 /var/lib/schroot/union/underlay/zz-27fe071c-f7a9-4278-a05e-4003536982f6
I: 10mount: mount: /srv/schroot/vendorname.centos-7 bound on /var/lib/schroot/union/underlay/zz-27fe071c-f7a9-4278-a05e-4003536982f6.
I: 10mount: Using 'overlayfs-workdir' for filesystem union
I: 10mount: mount: /proc bound on /var/lib/schroot/mount/zz-27fe071c-f7a9-4278-a05e-4003536982f6/proc.
I: 10mount: mount: /sys bound on /var/lib/schroot/mount/zz-27fe071c-f7a9-4278-a05e-4003536982f6/sys.
I: 10mount: mount: /dev bound on /var/lib/schroot/mount/zz-27fe071c-f7a9-4278-a05e-4003536982f6/dev.
I: 10mount: mount: /dev/pts bound on /var/lib/schroot/mount/zz-27fe071c-f7a9-4278-a05e-4003536982f6/dev/pts.
I: 10mount: mount: /dev/shm bound on /var/lib/schroot/mount/zz-27fe071c-f7a9-4278-a05e-4003536982f6/dev/shm.
I: 10mount: mount: /tmp bound on /var/lib/schroot/mount/zz-27fe071c-f7a9-4278-a05e-4003536982f6/tmp.
I: 10mount: mount: /home bound on /var/lib/schroot/mount/zz-27fe071c-f7a9-4278-a05e-4003536982f6/home.
I: 10mount: mount: /home/builder/TeamCity bound on /var/lib/schroot/mount/zz-27fe071c-f7a9-4278-a05e-4003536982f6/home/builder/TeamCity.
I: 10mount: mount: /home/builder/builds bound on /var/lib/schroot/mount/zz-27fe071c-f7a9-4278-a05e-4003536982f6/home/builder/builds.
I: 10mount: mount: /home/builder/vendorname bound on /var/lib/schroot/mount/zz-27fe071c-f7a9-4278-a05e-4003536982f6/home/builder/vendorname.
checking /proc/mounts:
(zz)builder@ip-10-83-26-25:/home/ubuntu$ cat /proc/mounts
zz / overlayfs rw,relatime,lowerdir=/home/builder/vendorname/noarch:/srv/schroot/vendorname.centos-7,upperdir=/home/builder/vendorname/vendorname.centos-7_Release,workdir=/home/builder/vendorname/overlay-work/vendorname.centos-7_Release-vendorname.centos-7 0 0
proc /proc proc rw,nosuid,nodev,noexec,relatime 0 0
sysfs /sys sysfs rw,nosuid,nodev,noexec,relatime 0 0
udev /dev devtmpfs rw,nosuid,relatime,size=15691036k,nr_inodes=3922759,mode=755 0 0
devpts /dev/pts devpts rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000 0 0
tmpfs /dev/shm tmpfs rw,nosuid,nodev,size=15707396k,nr_inodes=3926849 0 0
/dev/xvda1 /tmp ext4 rw,relatime,data=ordered 0 0
/dev/xvda1 /home ext4 rw,relatime,data=ordered 0 0
/dev/xvdf /home/builder/TeamCity btrfs rw,noatime,nodiratime,compress=zlib,ssd,space_cache,subvolid=271,subvol=/teamcity 0 0
/dev/xvdf /home/builder/builds btrfs rw,noatime,nodiratime,compress=zlib,ssd,space_cache,subvolid=276,subvol=/builds 0 0
/dev/xvdf /home/builder/vendorname btrfs rw,noatime,nodiratime,compress=zlib,ssd,space_cache,subvolid=273,subvol=/overlays 0 0
Ok, /home/builder/{TeamCity,buils,vendorname} is here...
Now entering the second chroot:
I: 10mount: Mounting /srv/schroot/vendorname.centos-7 on /var/lib/schroot/union/underlay/zz-a04bfa5f-200e-4603-9de7-b49389ec040b
I: 10mount: -v --bind /srv/schroot/vendorname.centos-7 /var/lib/schroot/union/underlay/zz-a04bfa5f-200e-4603-9de7-b49389ec040b
I: 10mount: mount: /srv/schroot/vendorname.centos-7 bound on /var/lib/schroot/union/underlay/zz-a04bfa5f-200e-4603-9de7-b49389ec040b.
I: 10mount: Using 'overlayfs-workdir' for filesystem union
I: 10mount: mount: /proc bound on /var/lib/schroot/mount/zz-a04bfa5f-200e-4603-9de7-b49389ec040b/proc.
I: 10mount: mount: /sys bound on /var/lib/schroot/mount/zz-a04bfa5f-200e-4603-9de7-b49389ec040b/sys.
I: 10mount: mount: /dev bound on /var/lib/schroot/mount/zz-a04bfa5f-200e-4603-9de7-b49389ec040b/dev.
I: 10mount: mount: /dev/pts bound on /var/lib/schroot/mount/zz-a04bfa5f-200e-4603-9de7-b49389ec040b/dev/pts.
I: 10mount: mount: /dev/shm bound on /var/lib/schroot/mount/zz-a04bfa5f-200e-4603-9de7-b49389ec040b/dev/shm.
I: 10mount: mount: /tmp bound on /var/lib/schroot/mount/zz-a04bfa5f-200e-4603-9de7-b49389ec040b/tmp.
I: 10mount: mount: /home bound on /var/lib/schroot/mount/zz-a04bfa5f-200e-4603-9de7-b49389ec040b/home.
I: 10mount: mount: /home/builder/TeamCity bound on /var/lib/schroot/mount/zz-a04bfa5f-200e-4603-9de7-b49389ec040b/home/builder/TeamCity.
I: 10mount: mount: /home/builder/builds bound on /var/lib/schroot/mount/zz-a04bfa5f-200e-4603-9de7-b49389ec040b/home/builder/builds.
I: 10mount: mount: /home/builder/vendorname bound on /var/lib/schroot/mount/zz-a04bfa5f-200e-4603-9de7-b49389ec040b/home/builder/vendorname.
(zz)builder@ip-10-83-26-25:/home/ubuntu$ cat /proc/mounts
zz / overlayfs rw,relatime,lowerdir=/home/builder/vendorname/noarch:/srv/schroot/vendorname.centos-7,upperdir=/home/builder/vendorname/vendorname.centos-7_Release,workdir=/home/builder/vendorname/overlay-work/vendorname.centos-7_Release-vendorname.centos-7 0 0
proc /proc proc rw,nosuid,nodev,noexec,relatime 0 0
sysfs /sys sysfs rw,nosuid,nodev,noexec,relatime 0 0
udev /dev devtmpfs rw,nosuid,relatime,size=15691036k,nr_inodes=3922759,mode=755 0 0
devpts /dev/pts devpts rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000 0 0
tmpfs /dev/shm tmpfs rw,nosuid,nodev,size=15707396k,nr_inodes=3926849 0 0
/dev/xvda1 /tmp ext4 rw,relatime,data=ordered 0 0
/dev/xvda1 /home ext4 rw,relatime,data=ordered 0 0
/dev/xvdf /home/builder/TeamCity btrfs rw,noatime,nodiratime,compress=zlib,ssd,space_cache,subvolid=271,subvol=/teamcity 0 0
/dev/xvdf /home/builder/builds btrfs rw,noatime,nodiratime,compress=zlib,ssd,space_cache,subvolid=276,subvol=/builds 0 0
/dev/xvdf /home/builder/vendorname btrfs rw,noatime,nodiratime,compress=zlib,ssd,space_cache,subvolid=273,subvol=/overlays 0 0
also all required mountpoints under /home/builder is here...
Now exiting the first chroot:
I: Executing ‘10mount setup-stop ok’
I: 10mount: Unmounting /var/lib/schroot/mount/zz-27fe071c-f7a9-4278-a05e-4003536982f6/home/builder/vendorname
I: 10mount: Unmounting /var/lib/schroot/mount/zz-27fe071c-f7a9-4278-a05e-4003536982f6/home/builder/builds
I: 10mount: Unmounting /var/lib/schroot/mount/zz-27fe071c-f7a9-4278-a05e-4003536982f6/home/builder/TeamCity
I: 10mount: Unmounting /var/lib/schroot/mount/zz-27fe071c-f7a9-4278-a05e-4003536982f6/dev/shm
I: 10mount: Unmounting /var/lib/schroot/mount/zz-27fe071c-f7a9-4278-a05e-4003536982f6/dev/pts
I: 10mount: Unmounting /var/lib/schroot/mount/zz-27fe071c-f7a9-4278-a05e-4003536982f6/home/builder/vendorname
I: 10mount: Unmounting /var/lib/schroot/mount/zz-27fe071c-f7a9-4278-a05e-4003536982f6/home/builder/builds
I: 10mount: Unmounting /var/lib/schroot/mount/zz-27fe071c-f7a9-4278-a05e-4003536982f6/home/builder/TeamCity
I: 10mount: Unmounting /var/lib/schroot/mount/zz-27fe071c-f7a9-4278-a05e-4003536982f6/home
I: 10mount: Unmounting /var/lib/schroot/mount/zz-27fe071c-f7a9-4278-a05e-4003536982f6/tmp
I: 10mount: Unmounting /var/lib/schroot/mount/zz-27fe071c-f7a9-4278-a05e-4003536982f6/dev/shm
I: 10mount: Unmounting /var/lib/schroot/mount/zz-27fe071c-f7a9-4278-a05e-4003536982f6/dev/pts
I: 10mount: Unmounting /var/lib/schroot/mount/zz-27fe071c-f7a9-4278-a05e-4003536982f6/dev
I: 10mount: Unmounting /var/lib/schroot/mount/zz-27fe071c-f7a9-4278-a05e-4003536982f6/sys
I: 10mount: Unmounting /var/lib/schroot/mount/zz-27fe071c-f7a9-4278-a05e-4003536982f6/proc
I: 10mount: Unmounting /var/lib/schroot/mount/zz-27fe071c-f7a9-4278-a05e-4003536982f6
I: 10mount: Unmounting /var/lib/schroot/union/underlay/zz-27fe071c-f7a9-4278-a05e-4003536982f6
and here is a strange things happened: all mountpoints under /home/builder are umounted twice!
Now in the second chroot:
(zz)builder@ip-10-83-26-25:/home/ubuntu$ cat /proc/mounts
zz / overlayfs rw,relatime,lowerdir=/home/builder/vendorname/noarch:/srv/schroot/vendorname.centos-7,upperdir=/home/builder/vendorname/vendorname.centos-7_Release,workdir=/home/builder/vendorname/overlay-work/vendorname.centos-7_Release-vendorname.centos-7 0 0
proc /proc proc rw,nosuid,nodev,noexec,relatime 0 0
sysfs /sys sysfs rw,nosuid,nodev,noexec,relatime 0 0
udev /dev devtmpfs rw,nosuid,relatime,size=15691036k,nr_inodes=3922759,mode=755 0 0
/dev/xvda1 /tmp ext4 rw,relatime,data=ordered 0 0
/dev/xvda1 /home ext4 rw,relatime,data=ordered 0 0
... they are just disappear! Now exiting the second chroot shows that there was no mountpoints under /home/builder!
I: Executing ‘10mount setup-stop ok’
I: 10mount: Unmounting /var/lib/schroot/mount/zz-a04bfa5f-200e-4603-9de7-b49389ec040b/home
I: 10mount: Unmounting /var/lib/schroot/mount/zz-a04bfa5f-200e-4603-9de7-b49389ec040b/tmp
I: 10mount: Unmounting /var/lib/schroot/mount/zz-a04bfa5f-200e-4603-9de7-b49389ec040b/dev
I: 10mount: Unmounting /var/lib/schroot/mount/zz-a04bfa5f-200e-4603-9de7-b49389ec040b/sys
I: 10mount: Unmounting /var/lib/schroot/mount/zz-a04bfa5f-200e-4603-9de7-b49389ec040b/proc
I: 10mount: Unmounting /var/lib/schroot/mount/zz-a04bfa5f-200e-4603-9de7-b49389ec040b
I: 10mount: Unmounting /var/lib/schroot/union/underlay/zz-a04bfa5f-200e-4603-9de7-b49389ec040b
Offering a clue as to what version of ...anything... you are using would really help.