今天刚好在红帽官方网站看到Ceph安装文档，我顺便动手测试一下。
参考文档
Ceph installation on CentOS 7.2
Install Ceph Infernalis(v9.2.0) in CentOS 7.2
管理节点
对于分布式文件系统，都是需要同步时间。而且这点经常由于忽略导致大问题。
yum install ntp
systemctl start ntpd
systemctl enable ntpd
设置FQDN
hostnamectl set-hostname ceph-admin.chenshake.com
设置 /etc/hosts
cat << EOF >> /etc/hosts
192.168.1.120 ceph-admin.chenshake.com ceph-admin
192.168.1.121 ceph-monitor1.chenshake.com ceph-monitor1
192.168.1.122 ceph-monitor2.chenshake.com ceph-monitor2
192.168.1.123 ceph-node1.chenshake.com ceph-node1
192.168.1.124 ceph-node2.chenshake.com ceph-node2
192.168.1.125 ceph-node3.chenshake.com ceph-node3
EOF
Cephuser 账号
groupadd -g 2000 cephgroup
useradd -c "ceph user" -g cephgroup -u 2000 cephuser
echo "cephuser:shake-pass" | chpasswd
sudo和tty
cat << EOF >/etc/sudoers.d/cephuser
cephuser ALL = (root) NOPASSWD:ALL
Defaults:cephuser !requiretty
EOF
chmod 0440 /etc/sudoers.d/cephuser
SSH (admin only)
创建ssh秘钥分发到所有节点上
su - cephuser
ssh-keygen -t rsa
cp -p .ssh/id_rsa.pub .ssh/authorized_keys
for H in ceph-monitor1 ceph-monitor2 ceph-node1 ceph-node2 ceph-node3 ; do scp -rp .ssh $H:. ; done