LVM Mirror Raid1管理.docx

测试环境：CentOS 5.10 x64，sda 20G，sdb 1G，sdc 2G.一、 创建逻辑卷镜像关系的步骤：1）通过pvcreate命令将linux分区处理成物理卷（PV)；2）通过vgcreate命令将创建好的物理卷处理成卷组（Vg)；3）通过lvcreate命令使用 m1 参数将卷若干个PV组成一个逻辑镜像卷（Lv)；之后我们可以对镜像逻辑卷进行格式化，挂载，删除等操作。二、 创建磁盘分区首先将sbc和sdc分区，并创建三个pv（sdb1、sdc1、sdc2），其中sdb1作为数据盘，sdc1作为镜像盘，sdc2作为日志盘，日志盘不应太小（一般10G左右）。1）将sdb分区rootCentos # fdisk /dev/sdbDevice contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabelBuilding a new DOS disklabel. Changes will remain in memory only,until you decide to write them. After that, of course, the previouscontent wont be recoverable.Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)Command (m for help): nCommand action e extended p primary partition (1-4)pPartition number (1-4): 1First cylinder (1-130, default 1): Using default value 1Last cylinder or +size or +sizeM or +sizeK (1-130, default 130): +1024MCommand (m for help): pDisk /dev/sdb: 1073 MB, 1073741824 bytes255 heads, 63 sectors/track, 130 cylindersUnits = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System/dev/sdb1 1 125 1004031 83 LinuxCommand (m for help): wThe partition table has been altered!Calling ioctl() to re-read partition table.Syncing disks.rootCentos #2）将sdc分区rootCentos # fdisl /dev/sdcbash: fdisl: command not foundrootCentos # fdisk /dev/sdcDevice contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabelBuilding a new DOS disklabel. Changes will remain in memory only,until you decide to write them. After that, of course, the previouscontent wont be recoverable.Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)Command (m for help): nCommand action e extended p primary partition (1-4)pPartition number (1-4): 1First cylinder (1-261, default 1): 1Last cylinder or +size or +sizeM or +sizeK (1-261, default 261): +1024MCommand (m for help): nCommand action e extended p primary partition (1-4)pPartition number (1-4): 2First cylinder (126-261, default 126): Using default value 126Last cylinder or +size or +sizeM or +sizeK (126-261, default 261): +1000MCommand (m for help): pDisk /dev/sdc: 2147 MB, 2147483648 bytes255 heads, 63 sectors/track, 261 cylindersUnits = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System/dev/sdc1 1 125 1004031 83 Linux/dev/sdc2 126 248 987997+ 83 LinuxCommand (m for help): wThe partition table has been altered!Calling ioctl() to re-read partition table.Syncing disks.3）重读分区表rootcentos # partprobe如果sdb、sdc是FC、iscsi、DAS存储，且配置了多路径，则使用如下命令更新分区表，若还未更新就只能 init 6 重启服务器了：kpartx a /dev/mapper/mpathbp1 然后 ls /dev/mapper/ 查看分区设备4）pvcreate 创建pv 设备rootCentos # pvcreate /dev/sdb1 /dev/sdc1 /dev/sdc2 Writing physical volume data to disk /dev/sdb1 Physical volume /dev/sdb1 successfully created Writing physical volume data to disk /dev/sdc1 Physical volume /dev/sdc1 successfully created Writing physical volume data to disk /dev/sdc2 Physical volume /dev/sdc2 successfully createdrootCentos # 查看pv设备表：rootcentos # pvscan （或者pvs，或者 pvdisplay查看详细信息包括pv uuid） PV /dev/sda2 VG VolGroup00 lvm2 19.88 GB / 0 free PV /dev/sdb1 lvm2 980.50 MB PV /dev/sdc1 lvm2 980.50 MB PV /dev/sdc2 lvm2 964.84 MB Total: 4 22.73 GB / in use: 1 19.88 GB / in no VG: 3 2.86 GBrootCentos #5）vgcreate创建 vg0物理卷组rootCentos # vgcreate vg0 /dev/sdb1 /dev/sdc1 /dev/sdc2 Volume group vg0 successfully createdrootCentos #三、 创建LVM Mirror镜像卷rootCentos # lvcreate -L 970M -m1 -n mirror vg0 /dev/sdb1 /dev/sdc1 Rounding up size to full physical extent 972.00 MB Logical volume mirror createdrootCentos # lvdisplay /dev/vg0/mirror 查看/dev/vg0/mirror - Logical volume - LV Name /dev/vg0/mirror VG Name vg0 LV UUID vX60P8-MmjC-tNX8-w2jI-t2qt-AZnD-Rnj0IN LV Write Access read/write LV Status available # open 0 LV Size 972.00 MB Current LE 243 Mirrored volumes 2 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 256 Block device 253:5rootCentos # lvs -a -o +devices 查看当前LVM中设备状态rootCentos # mkfs.ext3 /dev/vg0/mirror 格式化lvm，创建文件系统四、 管理lvm mirror卷1）破坏一个pv设备（sdb1），然后再查看lvs状态，发现少了一个pv设备sdb1：rootCentos # dd if=/dev/zero of=/dev/sdb1 count=1010+0 records in10+0 records out5120 bytes (5.1 kB) copied, 0.000856 seconds, 6.0 MB/s2）把损坏的pv从vg0卷组删除（缩小vg0卷组）：rootCentos # vgreduce -removemissing -force vg0Couldnt find device with uuid kJc1oG-Ua0R-RDiC-KaJ5-oomD-cH9Q-2DbWQ2.Wrote out consistent volume group vg0rootCentos #因为上面我们是手动破坏pv，如果是pv离线或者减少vg的pv设备，使用如下指令：rootCentos # vgreduce vg0 /dev/sdb1移除之后发现vg0详细信息中没有了Mirrored volumes选项rootCentos # vgdisplay /dev/vg0 - Volume group - VG Name vg0 System ID Format lvm2 Metadata Areas 2 Metadata Sequence No 9 VG Access read/write VG Status resizable MAX LV 0 Cur LV 1 Open LV 0 Max PV 0 Cur PV 2 Act PV 2 VG Size 1.91 GB PE Size 4.00 MB Total PE 490 Alloc PE / Size 243 / 972.00 MB Free PE / Size 247 / 988.00 MB VG UUID q620jv-Oc9a-pUlg-q6wM-TFXl-wAa7-jh40FsrootCentos #3）扩展vg0卷组：rootCentos # vgextend vg0 /dev/sdb1 扩展vg0卷组 Writing physical volume data to disk /dev/sdb1 Physical volume /dev/sdb1 successfully created Volume group vg0 successfully extendedrootCentos # pvs 查看pv状态 PV VG Fmt Attr PSize PFree /dev/sda2 VolGroup00 lvm2 a- 19.88G 0 /dev/sdb1 vg0 lvm2 a- 980.00M 980.00M /dev/sdc1 vg0 lvm2 a- 980.00M 8.00M /dev/sdc2 vg0 lvm2 a- 980.00M 980.00M4）镜像卷组数据恢复：rootCentos # lvconvert -m1 /dev/vg0/mirror /dev/sdb1 /dev/sdc1 /dev/sdc2 vg0/mirror: Converted: 0.0% vg0/mirror: Converted: 43.6% vg0/mirror: Converted: 83.5% vg0/mirror: Converted: 100.0%rootCentos #lvs -a -o +devices 查看mirror卷组状态，会看到三个pvrootCentos # lvdisplay /dev/vg0/mirror 查看lvm mirror详细信息，Mirrored volumes再次出现 - Logical volume - LV N