最近因為工作的需要在接觸GlusterFS，在未來的一段時間之內應該都要與之打交道，剛剛接觸分散式檔案系統，對很多概念和機制都不是很清楚，通過一段時間的學習有一點淺顯的認識，那麼就把這段時間的瞭解到的內容做個簡單的筆記，包括GlusterFS的基本概念，以及部署GlusterFS的方法。

1.glusterfs基本概念的介紹

因為對GlusterFS的整體架構理解的過於膚淺，那麼就只能對一些簡單的概念進行介紹。

brick：brick是任何在可信共享池中共享的目錄（Brick is basically any directory that is meant to be shared among the trusted storage pool

Trusted Storage Pool：這是共享檔案和目錄的的集合，這些檔案和目錄基於設計好的網路協議。（is a collection of these shared files/directories, which are based on the designed protocol.

Block Storage：They are devices through which the data is being moved across systems in the form of blocks.

Cluster：In Red Hat Storage, both cluster and trusted storage pool convey the same meaning of collaboration of storage servers based on a defined protocol.

Distributed File System：

FUSE：It is a loadable kernel module which allows users to create file systems above kernel without involving any of the kernel code.

glusterd：glusterd is the GlusterFS management daemon which is the backbone of file system which will be running throughout the whole time whenever the servers are in active state.

POSIX：Portable Operating System Interface (POSIX) is the family of standards defined by the IEEE as a solution to the compatibility between Unix-variants in the form of an Application Programmable Interface (API).

RAID：Redundant Array of Independent Disks (RAID) is a technology that gives increased storage reliability through redundancy.

Subvolume：A brick after being processed by least at one translator.

Translator：A translator is that piece of code which performs the basic actions initiated by the user from the mount point. It connects one or more sub volumes.

Volume：A volumes is a logical collection of bricks. All the operations are based on the different types of volumes created by the user. The volume,in turn,is mounted by the clients like a drive.

2.GlusterFS的部署方法。

作業系統：

centos6.4：

lsb_release -a

一共有三臺機器：

client：

10.23.85.47 glusterA

server：

10.23.85.48 glusterB
10.23.85.49 glusterC

在三臺機器上解壓檔案：

unzip gluster3.6.zip

在每臺機器上進行配置編譯安裝，注意還有一些必要的安裝包，那麼寫一個指令碼一起安裝run.sh（這個指令碼放在原始碼的根目錄下）：

yum install -y aclocal autoconf aotuheader automake libtool


yum install -y  automake autoconf libtool flex bison openssl-devel libxml2-devel python-devel libaio-devel libibverbs-devel librdmacm-devel readline-devel lvm2-devel glib2-devel userspace-rcu-devel libcmocka-devel
 
./configure --enable-debug                                     


sudo make


sudo make install

安裝好之後執行：

glusterfs --version

說明安裝完成，在三臺機器上執行同樣的操作。

add server to trusted storage pool：即將兩個儲存server節點組成一個叢集，本文在第一個server結點執行，在任何一個server結點執行即可。

http://www.gluster.org/community/documentation/index.php/Gluster_3.2:_Adding_Servers_to_Trusted_Sto

rage_Pool

error：connection failed.please check if gluster daemon is operational. 需要開啟glusterd守護程序

當然其他的server也要執行：service glusterd start命令，開啟守護進行，否則會報錯：peer probe: failed: Probe returned with unknown errno 107.

檢視叢集結點的資訊：

在server glusterB檢視：

在server glusterC檢視：

以/data/gluster為共享目錄，建立名為img的卷，副本數為2：

啟動volume並檢視卷狀態：

在客戶端掛載卷img：

首先用df -h命令檢視掛載資訊：

執行將卷img掛在到客戶端的/mnt掛載點上：

在部署好之後，我們嘗試對檔案進行操作，看看效果：

建立檔案：

client端：

server端：

刪除檔案：

client端：

server端：

至此，GlusterFS分散式檔案系統的基本概念和搭建工作完成。

3.問題總結：

1.在掛載的時候出現"Transport endpoint is not connected"的問題。

fusermount -uz /mnt

2.在serverA和serverB之間用scp拷貝資料"permission denied"的問題。

解決方法：首先在serverA上建立id_rsa.pub（如果之前沒有建的話）：ssh-keygen -t rsa，然後將生成的id_rsa.pub的內容拷貝到serverB的~/.ssh/authorized_keys檔案裡面，搞定。

3.在執行"gluster peer probe 10.23.85.38"操作的時候出現"peer probe: failed: Probe returned with unknown errno 107"。

有幾個原因：

>每臺機器上的glusterd沒有啟動，執行"service glusterd start"即可。

>確定機器之間是否能ping通。

Author：憶之獨秀

Email：[email protected]