Roentgen

General Information

Roentgen runs an Apache webserver, with wiki on top of it and shows you these pages. SO, if there are troubles with roentgen, you couldn't read this. Roentgen also hosts the MySQL server and the wiki. THIS wiki.

Hostnames: roentgen.unh.edu, roentgen.farm.physics.unh.edu
Alias: physics.farm.physics.unh.edu nuclear.farm.physics.unh.edu

Virtual Machine

Roentgen is a virtual machine. See Kvm It used to run on Taro, and was moved to Gourd on April 1, 2015. No joke. Previous attempts at moving roentgen had failed, apparently, so here is the recipe that worked: Moving A Virtual Machine

Virtual Hardware

Check with "virsh dumpxml roentgen.unh.edu" on the machine running roentgen!

• Memory: 8 GB
• Hard Disk: 60 GB
• CPU: 4 Virtual CPUs
• Swap Disk: 23 GB
• Network 1 (eth0): Farm-Bridge
• Network 2 (eth1): UNH-Bridge

The system has eth1 and eth1:1 to server roentgen.unh.edu and nuclear.unh.edu

Backup Configuration

/etc/rsync-backup.conf

# Backups are 'pull' only.  Too bad there isn't a better way to enforce this.
read only       = yes

# Oh for the ability to retain CAP_DAC_READ_SEARCH, and no other.  
uid             = root

# There's not much point in putting the superuser in a chroot jail
# use chroot    = no

# This isn't really an effective "lock" per se, since the value is per-module,
# but there really ought never be more than one, and it would at least 
# ensure serialized backups.
max connections = 1

[var]
        path    = /var
        comment = user and system storage
        filter  = - /lib/bind/proc

[srv]
        path    = /srv
        comment = published content

[usr_local]
        path    = /usr/local
        comment = unpackaged software

[opt]
        path    = /opt
        comment = unpackaged software

[etc]
        path    = /etc
        comment = conf files

[wheel]
        path    = /wheel
        comment = admin files
        filter  =               \
                : .rsync-filter \
                + /             \
                + /kickstart    \
                + /custom       \
                + /docs         \
                + /gpg-pubkey   \
                + /scripts      \
                - /*            \

Upgrade to Centos 7

Installed under the new name "roentgen2", and given the initial IP 10.0.0.149.
Install the VM using virt-install.

  virt-install -v --name=roentgen2 -r 8192 --os-type=linux --os-variant=rhel7 --cdrom=/scratch/CentOS-7-x86_64-Everything-1503-01.iso --disk=/kvm/images/roentgen2.qcow2,size=60 --accelerate --network=bridge:farmbr --network=bridge:unhbr --vnc --vncport=5904 --vcpus=4

• Temporary: set yum to use proxy, "yum update", "yum upgrade"
• Copy the /etc/ssh directory over from roentgen
• Setup networking scripts to take over from roentgen. Temporarily have IP "pepper.unh.edu"
• IMPORTANT: Follow Upgrading to Centos 7
• Get EPEL
  • yum install epel-release
• Get LDAP working.
  • copy LDAP setup from gourd:
    • scp -r gourd:/etc/sssd/* /etc/sssd/
    • rsync -av gourd:/etc/openldap .
    • yum install openldap-clients
    • systemctl restart sssd
    • getent passwd # TEST to see users.
  • Copy auto maps from roentgen
    • scp roentgen:/etc/auto* /etc/
    • systemctl restart autos
    • ls /net/home/maurik
  • Copy sudo users:
    • scp roentgen:/etc/sudoers /etc/sudoers
• Make sure backups work. Copy /root/.ssh and /etc/rsync-backup.conf

Get Virtual Console to work

See: Enable virus console

• edit /etc/default/grub and add console=ttyS0 to the GRUB_CMDLINE_LINUX
• regrub: grub2-mkconfig -o /boot/grub2/grub.cfg
• On host, make sure that serial tty is enabled. Not sure this is needed, but does work.
  • EDITOR=nano virsh edit roentgen2
    • add to <console type="pty"> tag:

 <console type='pty' tty='/dev/pts/6'> 
 <source path='/dev/pts/6'/> 
 <target type='serial' port='0'/> 
 <alias name='serial0'/> 
 </console>

• Follow the upgrade page: Gourd Upgrade to Centos 7

Web Server Setup

• First, mount the /www from gourd.
  • rm -rf /var/www
  • edit fstab, add npghome:/www /var/www nfs rw,soft,intr,rsize=32768,wsize=32768 0 0
  • mkdir /var/www
  • mount /var/www
  • ls /var/www # test
• Copy over the old configs from previous roentgen:
  • cd /etc
  • rm -rf httpd
  • rsync -av roentgen:/etc/httpd .
  • restart httpd, and fix errors: "systemctl restart httpd" -- get errors, see journalctl -xe
    • yum install mod_ldap
    • See: Apache docs 2.4 - Upgrading
    • See: Apache upgrade 2.2 to 2.4
    • remove the failing authn- and author- modules from the config.
  • Fix the SSL mess that existed on roentgen, well, sort of fix it. At least follow: Apache 2.4 SSL How To
  • Get an actually signed @#$@! certificate. See: CertBog Eff.org
    • Needed to install the certs with --standalone. That works when the httpd is stopped.