Gluster分布式存储--使用
实现功能：
把w1和w2上的/ application/nginx-1.10.2/html/blog/wp-content/uploads（wordpress图片目录）目录挂载到n1和n2的/data目录下
1.1.1 准备阶段
IP规划
w1 172.16.1.121
w2 172.16.1.122
n1 172.16.1.123
n2 172.16.1.124
查看阻碍
[root@web02 ~]# getenforce
Disabled
[root@web02 ~]# /etc/init.d/iptables status
iptables: Firewall is not running.
所有服务器都要解析,查看hosts解析情况
[root@web02 ~]# cat /etc/hosts
127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4
::1 localhost localhost.localdomain localhost6 localhost6.localdomain6
172.16.1.121 w1
172.16.1.122 w2
172.16.1.123 n1
172.16.1.124 n2
yum下载服务(需要特殊的gluster源)
wget -P /etc/yum.repos.d/ http://download.gluster.org/pub/gluster/glusterfs/3.7/LATEST/RHEL/glusterfs-epel.repo
yum install glusterfs-server -y
这里就统一都下载服务端用yum安装即可
一般是有服务端和客户端区分的，想要下载建议去官网下载https://www.gluster.org/ 需要编译安装
1.2 安装部署
开启服务（以下内容在n1、n2上操作即可，客户端不用操作/启动）
[root@n1 ~]# /etc/init.d/glusterd start
Starting glusterd: [ OK ]
把n2加入池（只在n1上操作）
[root@nfs01 ~]# gluster peer probe n2
peer probe: success. Host 10.0.0.61 port 24007 already in peer list
查看池子
[root@n1 ~]# gluster peer status
Number of Peers: 1 #显示除自己外的池子里还有几台服务器
Hostname: n2 #服务器的名字
Uuid: e530336c-d1f0-46b6-b431-d932679764d9 #如果磁盘或服务器挂了可以使用UUID恢复数据
State: Peer in Cluster (Connected)
最好用新的磁盘来做卷
插入一块磁盘sdb并创建分区
[root@n1 ~]# fdisk /dev/sdb
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-130, default 1):
Using default value 1
Last cylinder, +cylinders or +size{K,M,G} (1-130, default 130):
Using default value 130
Command (m for help): wq
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
创建完了磁盘分区然后格式化
[root@n1 ~]# mkfs.ext4 /dev/sdb1
挂载到要创建卷的目录/data上
[root@n1 ~]# mount -t ext4 /dev/sdb1 /data/
[root@n1 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 6.9G 3.2G 3.4G 49% /
tmpfs 491M 0 491M 0% /dev/shm
/dev/sda1 190M 33M 147M 19% /boot
/dev/sdb1 988M 1.3M 936M 1% /data
1.2.1 创建复制卷（以下内容只在n1上操作即可，n2不用操作）
[root@n1 ~]# gluster volume create pick replica 2 n1:/data/ n2:/data/ force
volume create: pick: success: please start the volume to access data
查看卷的信息
[root@n1 ~]# gluster volume info
Volume Name: pick #卷的名字
Type: Replicate #卷的类别（属于什么卷）
Volume ID: b4623968-3268-4bb9-b631-409355ebfe10 #卷的ID
Status: Created #卷的状态
Number of Bricks: 1 x 2 = 2 #一共有几个brick
Transport-type: tcp #什么协议（TCP/UDP/TCP+UDP）
Bricks:
Brick1: n1:/data #第一个brick目录
Brick2: n2:/data #第二个brick目录
Options Reconfigured:
performance.readdir-ahead: on
状态Status: Created是关闭的，所以要开启卷
[root@n1 ~]# gluster volume start pick
volume start: pick: success
检查是否开启
[root@n1 ~]# gluster volume info
Volume Name: pick
Type: Replicate
Volume ID: b4623968-3268-4bb9-b631-409355ebfe10
Status: Started
Number of Bricks: 1 x 2 = 2
Transport-type: tcp
Bricks:
Brick1: n1:/data
Brick2: n2:/data
Options Reconfigured:
performance.readdir-ahead: on
1.2.2 挂载卷
在w1和w2上，把wordpress图片目录挂载上即可（不用开启glusterd）
[root@w1 ~]# mount -t glusterfs n1:/pick /application/nginx/html/blog/wp-content/uploads/
[root@w1 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 6.9G 3.7G 2.8G 58% /
tmpfs 491M 0 491M 0% /dev/shm
/dev/sda1 190M 33M 147M 19% /boot
n1:/pick 988M 1.4M 936M 1% /application/nginx-1.10.2/html/blog/wp-content/uploads
1.2.3 取消挂载
[root@w1 ~]# umount /application/nginx-1.10.2/html/blog/wp-content/uploads
[root@w1 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 6.9G 3.7G 2.8G 58% /
tmpfs 491M 0 491M 0% /dev/shm
/dev/sda1 190M 33M 147M 19% /boot
1.2.4 停止卷
[root@n1 ~]# gluster volume stop pick
Stopping volume will make its data inaccessible. Do you want to continue? (y/n) y
volume stop: pick: success
1.2.5 移除brick（必须移除再删除卷）
[root@n1 ~]# gluster volume remove-brick pick replica 1 n1:/data/ force
Removing brick(s) can result in data loss. Do you want to Continue? (y/n) y
volume remove-brick commit force: success
移除一个即可
1.2.6 删除卷
[root@n1 ~]# gluster volume delete pick
Deleting volume will erase all information about the volume. Do you want to continue? (y/n) y
volume delete: pick: success
1.2.7 移除池
[root@n1 ~]# gluster peer detach n2
peer detach: success
1.2.8 磁盘平衡
磁盘平衡时很有必要的(平衡布局:rebalance)，因为布局结构是静态的，当新的bricks加入先有卷，新创建的文件会分布到旧的Bricks中，只有平衡布局(rebalance)，新加入的磁盘才会生效。
