-x(--spare-devices=)参数指定冗余磁盘的数量。另外，对于full的阵列（例如已经有2个磁盘的RAID1），则直接使用-add参数，mdadm会自动把冗余的磁盘作为spare disk。
7.删除RAID
#mdadm -S /dev/md0 或 #rm /dev/md0 删除/etc/mdadm.conf文件；去除/etc/fstab文件中相关的行。 最后，用fdisk对磁盘进行重新分区。
三 RAID之上建立LVM
1.前面还有一个/dev/sde没有处理，下面先把它建立成一个RAID1
[root@ ~]# fdisk /dev/sde The number of cylinders for this disk is set to 1044. There is nothing wrong with that, but this is larger than 1024, and could in certain setups cause problems with: 1) software that runs at boot time (e.g., old versions of LILO) 2) booting and partitioning software from other OSs (e.g., DOS FDISK, OS/2 FDISK) Command (m for help): p Disk /dev/sde: 8589 MB, 8589934592 bytes 255 heads, 63 sectors/track, 1044 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System Command (m for help): n Command action e extended p primary partition (1-4) p Partition number (1-4): 1 First cylinder (1-1044, default 1): Using default value 1 Last cylinder or +size or +sizeM or +sizeK (1-1044, default 1044): +5000M Command (m for help): n Command action e extended p primary partition (1-4) p Partition number (1-4): 2 First cylinder (610-1044, default 610): Using default value 610 Last cylinder or +size or +sizeM or +sizeK (610-1044, default 1044): Using default value 1044 Command (m for help): p Disk /dev/sde: 8589 MB, 8589934592 bytes 255 heads, 63 sectors/track, 1044 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/sde1 1 609 4891761 83 Linux /dev/sde2 610 1044 3494137+ 83 Linux Command (m for help): t Partition number (1-4): 1 Hex code (type L to list codes): fd Changed System type of partition 1 to fd (Linux raid autodetect) Command (m for help): t Partition number (1-4): 2 Hex code (type L to list codes): fd Changed System type of partition 2 to fd (Linux raid autodetect) Command (m for help): p Disk /dev/sde: 8589 MB, 8589934592 bytes 255 heads, 63 sectors/track, 1044 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/sde1 1 609 4891761 fd Linux raid autodetect /dev/sde2 610 1044 3494137+ fd Linux raid autodetect Command (m for help): w The partition table has been Calling ioctl() to re-read partition table. Syncing disks.
完成分区后，执行：
[root@ dev]# cd /dev/ [root@ dev]# ls -l md0 brw-r----- 1 root disk 9, 0 Aug 1 21:58 md0 [root@ dev]# mknod md1 b 9 1 [root@ dev]# mdadm --create /dev/md1 --level=1 --raid-devices=2 /dev/sde1 /dev/sde2 mdadm: largest drive (/dev/sde1) exceed size (3494016K) by more than 1% Continue creating array? y mdadm: array /dev/md1 started.
好了，RAID1也做完了，验证一下
[root@ dev]# mdadm -Ds ARRAY /dev/md0 level=raid5 num-devices=3 UUID=28a22990:eac5c231:3fe907f1:1145e264 ARRAY /dev/md1 level=raid1 num-devices=2 UUID=57f24dd1:aed3606c:d467132e:a6b3a010
2. 开始建立LVM
首先确保/dev/md0已经卸载，使用#umount /mnt/software
（1）创建PV
[root@ ~]# pvcreate /dev/md0 Physical volume "/dev/md0" successfully created [root@ ~]# pvcreate /dev/md1 Physical volume "/dev/md1" successfully created [root@ ~]# pvdisplay --- Physical volume --- PV Name /dev/sda2 VG Name VolGroup00 PV Size 13.90 GB / not usable 21.45 MB Allocatable yes (but full) PE Size (KByte) 32768 Total PE 444 Free PE 0 Allocated PE 444 PV UUID BntsgG-UJLv-agT2-lZ7C-dXY2-51FB-Jxd5tA --- NEW Physical volume --- PV Name /dev/md0 VG Name PV Size 16.00 GB Allocatable NO PE Size (KByte) 0 Total PE 0 Free PE 0 Allocated PE 0 PV UUID GriJk2-wyfl-o0CI-NY7t-g75X-zIx3-FJHf1u --- NEW Physical volume --- PV Name /dev/md1 VG Name PV Size 3.33 GB Allocatable NO PE Size (KByte) 0 Total PE 0 Free PE 0 Allocated PE 0 PV UUID SImCO1-RmvK-OgfZ-dCFZ-LJNC-8wun-Bd9qzS
（2）创建VG
[root@ ~]# vgcreate LVMonRaid /dev/md0 /dev/md1 Volume group "LVMonRaid" successfully created [root@ ~]# vgscan Reading all physical volumes. This may take a while... Found volume group "VolGroup00" using metadata type lvm2 Found volume group "LVMonRaid" using metadata type lvm2
创建了一个LVMonRaid的卷组。
（3）创建LV
[root@ ~]# lvcreate --size 5000M --name LogicLV1 LVMonRaid Logical volume "LogicLV1" created [root@ ~]# lvcreate --size 5000M --name LogicLV2 LVMonRaid Logical volume "LogicLV2" created [root@ ~]# lvscan ACTIVE '/dev/VolGroup00/LogVol00' [12.88 GB] inherit ACTIVE '/dev/VolGroup00/LogVol01' [1.00 GB] inherit ACTIVE '/dev/LVMonRaid/LogicLV1' [4.88 GB] inherit ACTIVE '/dev/LVMonRaid/LogicLV2' [4.88 GB] inherit 注：上面两条记录是装系统时默认创建的。
（4）格式化创建文件系统，并挂载使用
[root@ ~]# mkfs.ext3 /dev/LVMonRaid/LogicLV1 mke2fs 1.39 (29-May-2006) Filesystem label= OS type: Linux Block size=4096 (log=2) Fragment size=4096 (log=2) 640000 inodes, 1280000 blocks 64000 blocks (5.00%) reserved for the super user First data block=0 Maximum filesystem blocks=1312817152 40 block groups 32768 blocks per group, 32768 fragments per group 16000 inodes per group Superblock backups stored on blocks: 32768, 98304, 163840, 229376, 294912, 819200, 884736 Writing inode tables: done Creating journal (32768 blocks): done Writing superblocks and filesystem accounting information: done This filesystem will be automatically checked every 35 mounts or 180 days, whichever comes first. Use tune2fs -c or -i to override. [root@ ~]# mkfs.ext3 /dev/LVMonRaid/LogicLV2 mke2fs 1.39 (29-May-2006) Filesystem label= OS type: Linux Block size=4096 (log=2) Fragment size=4096 (log=2) 640000 inodes, 1280000 blocks 64000 blocks (5.00%) reserved for the super user First data block=0 Maximum filesystem blocks=1312817152 40 block groups 32768 blocks per group, 32768 fragments per group 16000 inodes per group Superblock backups stored on blocks: 32768, 98304, 163840, 229376, 294912, 819200, 884736 Writing inode tables: done Creating journal (32768 blocks): done Writing superblocks and filesystem accounting information: done This filesystem will be automatically checked every 33 mounts or 180 days, whichever comes first. Use tune2fs -c or -i to override. [root@ ~]# mkdir /mnt/doc [root@ ~]# mkdir /mnt/music [root@ ~]# mount -t ext3 /dev/LVMonRaid/LogicLV1 /mnt/doc [root@ ~]# mount -t ext3 /dev/LVMonRaid/LogicLV2 /mnt/music 如果要开机自动挂载，更改/etc/fstab文件，添加如下两行： /dev/LVMonRaid/LogicLV1 /mnt/doc ext3 defaults 0 0