1、soft raid (package:mdadm-2.6.9-2.el5)
常用raid有0,1,5三种模式.5中还可以加入一个备用的磁盘,以待备用,当磁盘坏了,马上加入阵列,并替换坏的磁盘.在此只做raid5的实验. step 1、在虚拟机上加入5个磁盘.在linux下识别为：/dev/sd{b,c,d,e,f} step 2、使用mdadm指令创建raid5 mdadm --create /dev/md0 -l 5 -n 3 -x 1 /dev/sdb /dev/sdc /dev/sdd /dev/sde step 3、查看状态 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 : 3Total Devices : 4Preferred 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 : 0Spare Devices : 1Layout : 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/sdd3 8 64 - spare /dev/sdestep 4、把md0装置写入配置文件(如果不写入些文件可能会导致重启后此raid5不能使用) mdadm --detail --scan >>/etc/mdadm.conf step 5、格式化磁盘 mke2fs -j /dev/md0 step 6、挂载并测试 mount /dev/md0 /mnt step 7、如果需要开机的时候就自动挂载的话写入/etc/fstab. 测试当磁盘坏的时候,spare disk自动替换 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 : 1Spare Devices : 1 Layout : left-symmetric Chunk Size : 64KRebuild Status : 9% complete (正在还原)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/sdd4 8 32 - faulty spare /dev/sdc(此处显示有一个坏)setp 3、替换坏的磁盘 mdadm --manage /dev/md0 --add /dev/sdf --remove /dev/sdc setp 4、检查是否成功替换 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 : cleanActive Devices : 3Working Devices : 4Failed Devices : 0Spare Devices : 1Layout : 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/sdd3 8 80 - spare /dev/sdf(已成功替换)