004.Ceph块设备基础使用

一 基础准备

• 参考《002.Ceph安装部署》文档部署一个基础集群；
• 新增节点主机名及IP在deploy节点添加解析：

 [root@deploy ~]# echo "172.24.8.75 cephclient" >>/etc/hosts

• 配置国内yum源：

 [root@cephclient ~]# yum -y update
 [root@cephclient ~]# rm /etc/yum.repos.d/* -rf
 [root@cephclient ~]# wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
 [root@cephclient ~]# yum -y install epel-release
 [root@cephclient ~]# mv /etc/yum.repos.d/epel.repo /etc/yum.repos.d/epel.repo.backup
 [root@cephclient ~]# mv /etc/yum.repos.d/epel-testing.repo /etc/yum.repos.d/epel-testing.repo.backup
 [root@cephclient ~]# wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo

 

二 块设备

2.1 添加普通用户

 [root@cephclient ~]# useradd -d /home/cephuser -m cephuser
 [root@cephclient ~]# echo "cephuser" | passwd --stdin cephuser	#cephclient节点创建cephuser用户
 [root@cephclient ~]# echo "cephuser ALL = (root) NOPASSWD:ALL" > /etc/sudoers.d/cephuser
 [root@cephclient ~]# chmod 0440 /etc/sudoers.d/cephuser
 [root@deploy ~]# su - manager
 [manager@deploy ~]$ ssh-copy-id -i ~/.ssh/id_rsa.pub cephuser@172.24.8.75

 

2.2 安装ceph-client

 [root@deploy ~]# su - manager
 [manager@deploy ~]$ cd my-cluster/
 [manager@deploy my-cluster]$ vi ~/.ssh/config
 Host node1
    Hostname node1
    User cephuser
 Host node2
    Hostname node2
    User cephuser
 Host node3
    Hostname node3
    User cephuser
 Host cephclient
    Hostname cephclient						#新增cephclient节点信息
    User cephuser
 [manager@deploy my-cluster]$ ceph-deploy install cephclient	#安装Ceph

 

注意：若使用ceph-deploy部署的时候出现安装包无法下载，可在部署时候指定ceph.repo为国内源：

 ceph-deploy install cephclient --repo-url=https://mirrors.aliyun.com/ceph/rpm-mimic/el7/ --gpg-url=https://mirrors.aliyun.com/ceph/keys/release.asc

 [manager@deploy my-cluster]$ ceph-deploy admin cephclient

提示：为方便后期deploy节点管理cephclient，在CLI中使用命令中简化相关key的输出，可将key复制至相应节点。ceph-deploy 工具会把密钥环复制到/etc/ceph目录，要确保此密钥环文件有读权限（如 sudo chmod +r /etc/ceph/ceph.client.admin.keyring ）。

2.3 创建pool

 [manager@deploy my-cluster]$ ssh node1 sudo ceph osd pool create mytestpool 64

2.4 初始化pool

 [root@cephclient ~]# ceph osd lspools
 [root@cephclient ~]# rbd pool init mytestpool

 

2.5 创建块设备

 [root@cephclient ~]# rbd create mytestpool/mytestimages --size 4096 --image-feature layering

2.6 确认验证

 [root@cephclient ~]# rbd ls mytestpool
 mytestimages
 [root@cephclient ~]# rbd showmapped
 id pool       image        snap device
 0  mytestpool mytestimages -    /dev/rbd0
 [root@cephclient ~]# rbd info mytestpool/mytestimages

 

2.7 将image映射为块设备

 [root@cephclient ~]# rbd map mytestpool/mytestimages --name client.admin
 /dev/rbd0

 

2.8 格式化设备

 [root@cephclient ~]# mkfs.ext4 /dev/rbd/mytestpool/mytestimages
 [root@cephclient ~]# lsblk

 

2.9 挂载并测试

 [root@cephclient ~]# sudo mkdir /mnt/ceph-block-device
 [root@cephclient ~]# sudo mount /dev/rbd/mytestpool/mytestimages /mnt/ceph-block-device/
 [root@cephclient ~]# cd /mnt/ceph-block-device/
 [root@cephclient ceph-block-device]# echo 'This is my test file!' >> test.txt
 [root@cephclient ceph-block-device]# ls
 lost+found  test.txt

 

2.10 自动map

 [root@cephclient ~]# vim /etc/ceph/rbdmap
 # RbdDevice     Parameters
 #poolname/imagename id=client,keyring=/etc/ceph/ceph.client.keyring
 mytestpool/mytestimages id=admin,keyring=/etc/ceph/ceph.client.admin.keyring

 

2.11 开机挂载

 [root@cephclient ~]# vi /etc/fstab
 #……
 /dev/rbd/mytestpool/mytestimages    /mnt/ceph-block-device  ext4    defaults,noatime,_netdev    0 0

 

2.12 rbdmap开机启动

 [root@cephclient ~]# systemctl enable rbdmap.service
 [root@cephclient ~]# df -hT				#查看验证

 

提示：若出现开机后依旧无法自动挂载，rbdmap也异常，可如下操作：

 [root@cephclient ~]# vi /usr/lib/systemd/system/rbdmap.service
 [Unit]
 Description=Map RBD devices
 WantedBy=multi-user.target			#需要新增此行
 #……