Comment 34 for bug 1381170

Ok, I tried ubuntu as well. I get the same problem. Looks to be pretty much screwed.

root@ubuntu:~# cd /target
root@ubuntu:/target# cd
root@ubuntu:~# sudo mount /dev/md126p5 /target
root@ubuntu:~# cd /target
root@ubuntu:/target# sudo mount -t proc proc proc/
root@ubuntu:/target# sudo mount -t sysfs sys sys/
root@ubuntu:/target# sudo mount -o bind /dev dev/
root@ubuntu:/target# chroot .
root@ubuntu:/# sudo apt-get install mdadm grub2
sudo: unable to resolve host ubuntu
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following extra packages will be installed:
  grub-gfxpayload-lists grub-pc grub-pc-bin postfix
Suggested packages:
  desktop-base procmail postfix-mysql postfix-pgsql postfix-ldap postfix-pcre
  sasl2-bin dovecot-common postfix-cdb postfix-doc
Recommended packages:
  default-mta mail-transport-agent
The following packages will be REMOVED:
  grub-efi-amd64 grub-efi-amd64-signed
The following NEW packages will be installed:
  grub-gfxpayload-lists grub-pc grub-pc-bin grub2 mdadm postfix
0 upgraded, 6 newly installed, 2 to remove and 106 not upgraded.
Need to get 2,505 kB of archives.
After this operation, 5,127 kB of additional disk space will be used.
Do you want to continue? [Y/n] y
Err http://us.archive.ubuntu.com/ubuntu/ trusty-updates/main grub-pc-bin amd64 2.02~beta2-9ubuntu1.3
  Could not resolve 'us.archive.ubuntu.com'
Err http://us.archive.ubuntu.com/ubuntu/ trusty-updates/main grub-pc amd64 2.02~beta2-9ubuntu1.3
  Could not resolve 'us.archive.ubuntu.com'
Err http://us.archive.ubuntu.com/ubuntu/ trusty/main grub-gfxpayload-lists amd64 0.6
  Could not resolve 'us.archive.ubuntu.com'
Err http://us.archive.ubuntu.com/ubuntu/ trusty-updates/main mdadm amd64 3.2.5-5ubuntu4.2
  Could not resolve 'us.archive.ubuntu.com'
Err http://us.archive.ubuntu.com/ubuntu/ trusty-updates/main postfix amd64 2.11.0-1ubuntu1
  Could not resolve 'us.archive.ubuntu.com'
Err http://us.archive.ubuntu.com/ubuntu/ trusty-updates/universe grub2 amd64 2.02~beta2-9ubuntu1.3
  Could not resolve 'us.archive.ubuntu.com'
E: Failed to fetch http://us.archive.ubuntu.com/ubuntu/pool/main/g/grub2/grub-pc-bin_2.02~beta2-9ubuntu1.3_amd64.deb Could not resolve 'us.archive.ubuntu.com'

E: Failed to fetch http://us.archive.ubuntu.com/ubuntu/pool/main/g/grub2/grub-pc_2.02~beta2-9ubuntu1.3_amd64.deb Could not resolve 'us.archive.ubuntu.com'

E: Failed to fetch http://us.archive.ubuntu.com/ubuntu/pool/main/g/grub-gfxpayload-lists/grub-gfxpayload-lists_0.6_amd64.deb Could not resolve 'us.archive.ubuntu.com'

E: Failed to fetch http://us.archive.ubuntu.com/ubuntu/pool/main/m/mdadm/mdadm_3.2.5-5ubuntu4.2_amd64.deb Could not resolve 'us.archive.ubuntu.com'

E: Failed to fetch http://us.archive.ubuntu.com/ubuntu/pool/main/p/postfix/postfix_2.11.0-1ubuntu1_amd64.deb Could not resolve 'us.archive.ubuntu.com'

E: Failed to fetch http://us.archive.ubuntu.com/ubuntu/pool/universe/g/grub2/grub2_2.02~beta2-9ubuntu1.3_amd64.deb Could not resolve 'us.archive.ubuntu.com'

E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?