第五章 Raid與LVM高階文件系統。

1、soft raid (package:mdadm-2.6.9-2.el5)

常用raid有0,1,5三種模式.5中還可以加入一個備用的磁碟,以待備用,當磁碟壞了,馬上加入陣列,並替換壞的磁碟. 在此只做raid5的實驗. step 1、在虛擬機上加入5個磁碟.在linux下識別為：/dev/sd{b,c,d,e,f} step 2、使用mdadm指令創建raid5 mdadm --create /dev/md0 -l 5 -n 3 -x 1 /dev/sdb /dev/sdc /dev/sdd /dev/sde step 3、查看狀態 cat /proc/mdstat 或者 mdadm --detail /dev/md0 [root@localhost ~]# mdadm --detail /dev/md0 /dev/md0: Version : 0.90 Creation Time : Wed Apr 18 05:43:05 2012 Raid Level : raid5 Array Size : 10485632 (10.00 GiB 10.74 GB) Used Dev Size : 5242816 (5.00 GiB 5.37 GB) Raid Devices : 3 Total Devices : 4 Preferred Minor : 0 Persistence : Superblock is persistent Update Time : Wed Apr 18 05:47:32 2012 State : clean Active Devices : 3 Working Devices : 4 Failed Devices : 0 Spare Devices : 1 Layout : left-symmetric Chunk Size : 64K UUID : b009524a:05f9aca5:c12992b9:ba85a2a0 Events : 0.2 Number Major Minor RaidDevice State 0 8 16 0 active sync /dev/sdb 1 8 32 1 active sync /dev/sdc 2 8 48 2 active sync /dev/sdd 3 8 64 - spare /dev/sde step 4、把md0裝置寫入配置文件(如果不寫入些文件可能會導致重啟后此raid5不能使用) mdadm --detail --scan >>/etc/mdadm.conf step 5、格式化磁碟 mke2fs -j /dev/md0 step 6、掛載並測試 mount /dev/md0 /mnt step 7、如果需要開機的時候就自動掛載的話寫入/etc/fstab. 測試當磁碟壞的時候,spare disk自動替換 step 1、 mdadm --manage /dev/md0 --fail /dev/sdc step 2、 mdadm --detail /dev/md0 [root@localhost ~]# mdadm --detail /dev/md0 /dev/md0: Version : 0.90 Creation Time : Wed Apr 18 05:43:05 2012 Raid Level : raid5 Array Size : 10485632 (10.00 GiB 10.74 GB) Used Dev Size : 5242816 (5.00 GiB 5.37 GB) Raid Devices : 3 Total Devices : 4 Preferred Minor : 0 Persistence : Superblock is persistent Update Time : Wed Apr 18 06:07:01 2012 State : clean, degraded, recovering Active Devices : 2 Working Devices : 3 Failed Devices : 1 Spare Devices : 1 Layout : left-symmetric Chunk Size : 64K Rebuild Status : 9% complete (正在還原) UUID : b009524a:05f9aca5:c12992b9:ba85a2a0 Events : 0.4 Number Major Minor RaidDevice State 0 8 16 0 active sync /dev/sdb 3 8 64 1 spare rebuilding /dev/sde 2 8 48 2 active sync /dev/sdd 4 8 32 - faulty spare /dev/sdc(此處顯示有一個壞) setp 3、替換壞的磁碟 mdadm --manage /dev/md0 --add /dev/sdf --remove /dev/sdc setp 4、檢查是否成功替換 mdadm --detail /dev/md0 [root@localhost ~]# mdadm --detail /dev/md0 /dev/md0: Version : 0.90 Creation Time : Wed Apr 18 05:43:05 2012 Raid Level : raid5 Array Size : 10485632 (10.00 GiB 10.74 GB) Used Dev Size : 5242816 (5.00 GiB 5.37 GB) Raid Devices : 3 Total Devices : 4 Preferred Minor : 0 Persistence : Superblock is persistent Update Time : Wed Apr 18 06:20:58 2012 State : clean Active Devices : 3 Working Devices : 4 Failed Devices : 0 Spare Devices : 1 Layout : left-symmetric Chunk Size : 64K UUID : b009524a:05f9aca5:c12992b9:ba85a2a0 Events : 0.8 Number Major Minor RaidDevice State 0 8 16 0 active sync /dev/sdb 1 8 64 1 active sync /dev/sde 2 8 48 2 active sync /dev/sdd 3 8 80 - spare /dev/sdf(已成功替換)

本文出自 「Linux」 博客,請務必保留此出處http://837244.blog.51cto.com/827244/837610

Tags: linux system 系統