Installation of the Virtual Machines and copy the production server
A list:
- Find server infrastructure. Eventually, the service will run on DMU's converged private cloud but for now I'm making do with a DL360 G6 which will hopefully have two 4 Core CPUS and 16-32GB RAM. Disaster recovery will be covered through thorough backup up of what is at the moment a small amount of data. Users have the ability to upload up to 4.5GB in to a blog at a time...
- Install CentOS 6.3
- 400GB, 50GB for the OS and the rest for VMs and storage in /usr1 including install ISOs
- yum groupinstall "Virtualisation" "Virtualization Client" "Virtualization Platform" "Virtualization Tools" "Web Server" "PHP Support"
- Setup networking on the host to include br0
- added this to /etc/sysctl.d/libvirtd (might be crazy)
- net.bridge.bridge-nf-call-ip6tables = 0
- net.bridge.bridge-nf-call-iptables = 0
- net.bridge.bridge-nf-call-arptables = 0
- wondering about Jumbo frames over br0 for storage???
- Add tap0 to br0 for better networking :
-
yum install tunctl
# /etc/rc.local /usr/sbin/tunctl -b /sbin/ifconfig tap0 up /usr/sbin/brctl addif br0 tap0
- added this to /etc/sysctl.d/libvirtd (might be crazy)
- dd if=/dev/zero of=/usr1/local/storage/commonstg1.img bs=1M seek=204800 count=0 #200GB sparse iSCSI storage image
- vi /etc/tgt/targets.conf and append
-
<target iqn.2012-09.uk.ac.dmu.blue:commonstg1> initiator-address 146.227.XX.XX <direct-store /usr1/local/storage/commonstg1.img> lun 1 </direct-store> </target>
-
- Creating a 20GB (generous today) VM for MySQL
- virt-install --connect qemu:///system -n CommonsDBVM -r 2048 --vcpus=2 --disk path=/usr1/local/vm/CommonsDBVM.img,size=20 -c /usr/local/iso/CentOS-6.3-x86_64-netinstall.iso --vnc --noautoconsole --os-type linux --os-variant rhel6 --accelerate --network=bridge:br0 --hvm
- Set up networking (manually)
- yum update, install rsync wget, groupinstall "MySQL Database client" "MySQL Database server"
- Change SSHD config to allow passphrases but not passwords (having applied public keys to authorized_keys)
- (make a decision about SELinux)
- grab a database backup (and Commons WP backup) for testing the install
- set MySQL's admin password
- change iptables to reflect MySQL comms with Common's web server
- mysql -u root -p < backup.sql
- grant ownership to database for user remembering remote hostname
- Creating a 20GB (generous today) VM for Commons Web (storage will be iSCSI on VMs' host for now)
- yum update, install rsync wget, groupinstall "Web Server", php-pecl-apc
- Change SSHD config to allow passphrases but not passwords (having applied public keys to authorized_keys)
- (make a decision about SELinux)
- iscsiadm --mode discovery --type sendtargets --portal 146.227.XX.XX
- iscsiadm --mode node --targetname iqn.2012-09.uk.ac.dmu.blue:commonstg1 --portal 146.227.XX.XX --login
- tail -f /var/log/messages (to verify and discover your new disk)
- service iscsi restart (for a laugh)
- fdisk -l /dev/yourNewDisk (sda for me)
- create one partition the size of the disk and set to LVM
- pvcreate /dev/sda1
- vgcreate vg_commonswebdata /dev/sda1
- lvcreate -L 199G -nusr1lv vg_commonswebdata
- mkfs.ext4 -L /usr1 /dev/vg_commonswebdata/usr1lv
- tune2fs -c -1 -i -1 -m 1 /dev/vg_commonswebdata/usr1lv
- Add entry to /etc/fstab
-
LABEL=/usr1 /usr1 ext4 _netdev 0 0
-
- Reboot the VM with fingers crossed the storage comes up and gets mounted. For me, wowzers, it's there.
- Back on the host list the VMs and make them boot at boot:
-
# virsh list Id Name State ---------------------------------------------------- 1 CommonsDBVM running 2 CommonsWebVM running
[root@winsor ~]# virsh autostart CommonsDBVM Domain CommonsDBVM marked as autostarted
[root@winsor ~]# virsh autostart CommonsWebVM Domain CommonsWebVM marked as autostarted
- Reboot the host and check the VMs come up with the iSCSI storage mounted. For me "Wuhoo!"
- Back on CommonsWeb:
- yum install php-mysql mysql php-ldap and check connection to remote database
- Configured Apache to reflect current Commons website
- Changed /etc/hosts to include IP/hostnames for testing
- restored WP backup (correlating to database restore)
- Mustn't forget back ups of host and VMs. We use Amanda which is super good for Linux and web servers. Large media files and large VM images are a problem but for now we're living with it. On the VMs' host I exclude ISOs, VMs and the storage as I'm backing up the VMs' file systems. This avoids backing up large images because of a small change to a VM and keeps data related to the host in one place.
- Tune PHP and MySQL
- MySQL first:
-
[mysqld] datadir=/var/lib/mysql socket=/var/lib/mysql/mysql.sock user=mysql # Disabling symbolic-links is recommended to prevent assorted security risks symbolic-links=0
query_cache_limit=1M query_cache_size=32M query_cache_type=1 max_connections=3000 max_user_connections=600 interactive_timeout=100 wait_timeout=100 connect_timeout=10 thread_cache_size=128 key_buffer=256M # 64M for 1GB, 128M for 2GB, 256 for 4GB join_buffer_size=4M # 1M for 1GB, 2M for 2GB, 4M for 4GB max_allowed_packet=32M table_cache=1024 sort_buffer_size=4M # 1M for 1GB, 2M for 2GB, 4M for 4GB read_buffer_size=4M # 1M for 1GB, 2M for 2GB, 4M for 4GB read_rnd_buffer_size=3072K # 768K for 1GB, 1536K for 2GB, 3072K for 4GB max_connect_errors=10 thread_concurrency=4 myisam_sort_buffer_size=128M # 32M for 1GB, 64M for 2GB, 128 for 4GB skip-locking
[mysqld_safe] log-error=/var/log/mysqld.log pid-file=/var/run/mysqld/mysqld.pid
[isamchk] key_buffer=256M # 64M for 1GB, 128M for 2GB, 256M for 4GB sort_buffer=256M # 64M for 1GB, 128M for 2GB, 256M for 4GB read_buffer=64M # 16M for 1GB, 32M for 2GB, 64M for 4GB write_buffer=64M # 16M for 1GB, 32M for 2GB, 64M for 4GB
[myisamchk] key_buffer=256M # 64M for 1GB, 128M for 2GB, 256M for 4GB sort_buffer=256M # 64M for 1GB, 128M for 2GB, 256M for 4GB read_buffer=64M # 16M for 1GB, 32M for 2GB, 64M for 4GB write_buffer=64M # 16M for 1GB, 32M for 2GB, 64M for 4GB
Hmmm...I seem to have a working copy of our website spread across two VMs.
