lvm的一些操作
首先就是创建PV了，有了PV才能组建VG嘛。创建PV用 pvcreate 命令。
# pvcreate /dev/hda6
Physical volume "/dev/hda6"> # pvdisplayPV Name /dev/hda6 VG Name PV Size 9.77 GB Allocatable NO PE Size (KByte) 0 Total PE 0 Free PE 0 Allocated PE 0 PV UUID jGIjyo-lukG-LdRg-tmwe-Mgxf-09ZW-loquUZ这样可以看到，创建了一个PV。同样操作可以创建多个。下面创建VG。 # vgcreate wd /dev/hda6Volume group "wd"> # vgdisplayVG Name wd System ID Format lvm2 Metadata Areas 1 Metadata Sequence No 1 VG Access read/write VG Status resizable MAX LV 0 Cur LV 0 Open LV 0 Max PV 0 Cur PV 1 Act PV 1 VG Size 9.77 GB PE Size 4.00 MB Total PE 2500 Alloc PE / Size 0 / 0 Free PE / Size 2500 / 9.77 GB VG UUID NwUlxW-AmAi-LyqA-h39E-zS7q-YRj3-scZucL再看刚才创建的pv。 # pvdisplayPV Name /dev/hda6 VG Name wd PV Size 9.77 GB / not usable 0 Allocatable yes PE Size (KByte) 4096 Total PE 2500 Free PE 2500 Allocated PE 0 PV UUID jGIjyo-lukG-LdRg-tmwe-Mgxf-09ZW-loquUZ可以看到多了一些信息，他已经属于叫做wd的VG了。同时可以看到PE的大小是4096K，也就是4M。下面创建真正可用的LV。 # lvcreate -L 200M -n test wdLogical volume "test"> # lvdisplayLV Name /dev/wd/test VG Name wd LV UUID sPy1bM-Nz13-v0x7-bk0V-BKSH-Udzl-7ov5jM LV Write Access read/write LV Status available # open 0 LV Size 200.00 MB Current LE 50 Segments 1 Allocation inherit Read ahead sectors 0 Block device 253:0可以看到，已经创建了一个叫做test的LV，也可以不使用-n参数指定LV的名称，这样系统会给取一个名字。 再来看看VG和PV的信息。 # vgdisplayVG Name wd System ID Format lvm2 Metadata Areas 1 Metadata Sequence No 4 VG Access read/write VG Status resizable MAX LV 0 Cur LV 1 Open LV 0 Max PV 0 Cur PV 1 Act PV 1 VG Size 9.77 GB PE Size 4.00 MB Total PE 2500 Alloc PE / Size 50 / 200.00 MB Free PE / Size 2450 / 9.57 GB VG UUID NwUlxW-AmAi-LyqA-h39E-zS7q-YRj3-scZucL# pvdisplayPV Name /dev/hda6 VG Name wd PV Size 9.77 GB / not usable 0 Allocatable yes PE Size (KByte) 4096 Total PE 2500 Free PE 2450 Allocated PE 50 PV UUID jGIjyo-lukG-LdRg-tmwe-Mgxf-09ZW-loquUZ可以看到VG已经使用了50个PE，也就是200M空间。PV上面也是，使用了50个PE。 这样LV已经有了，怎么使用他呢？其实和普通分区的使用方法一样。先格式化，创建文件系统，然后挂载。 # mkfs.ext3 /dev/wd/testmax_blocks 209715200, rsv_groups = 25600, rsv_gdb = 256 Filesystem label= OS type: Linux Block size=1024 (log=0) Fragment size=1024 (log=0) 51200 inodes, 204800 blocks 10240 blocks (5.00%) reserved for the super user First data block=1 Maximum filesystem blocks=67371008 25 block groups 8192 blocks per group, 8192 fragments per group 2048 inodes per group Superblock backups stored on blocks: 8193, 24577, 40961, 57345, 73729 Writing inode tables: done inode.i_blocks = 3074, i_size = 67383296 Creating journal (4096 blocks): done Writing superblocks and filesystem accounting information: done This filesystem will be automatically checked every 38 mounts or 180 days, whichever comes first. Use tune2fs -c or -i to override.# mount /dev/wd/test /opt ]# df -h/dev/hda9 4.0G 148M 3.6G 4% / /dev/hda1 99M 8.3M 86M 9% /boot /dev/hda3 29G 1.1G 27G 4% /data none 252M 0 252M 0% /dev/shm /dev/hda7 9.7G 55M 9.1G 1% /home /dev/hda10 3.9G 40M 3.7G 2% /tmp /dev/hda5 9.7G 1.9G 7.4G 20% /usr /dev/hda8 7.7G 90M 7.3G 2% /var /dev/mapper/wd-test 194M 5.6M 179M 4% /opt最后这行就是挂载的LV。下面调整LV的大小。先umount挂载的LV。 # umount /opt # lvresize -L +100M /dev/wd/testLogical volume test successfully resized# lvdisplayLV Name /dev/wd/test VG Name wd LV UUID sPy1bM-Nz13-v0x7-bk0V-BKSH-Udzl-7ov5jM LV Write Access read/write LV Status available # open 0 LV Size 300.00 MB Current LE 75 Segments 1 Allocation inherit Read ahead sectors 0 Block device 253:0然后需要使用resize2fs命令调整LV分区大小。我这里用的是rh el4，没有这个命令。rh el3里面有这个命令。el4里面用ext2online命令调整，用ext2online命令调整的话，需要把要调整的分区挂载上去。 # mount /dev/wd/test /opt # ext2online /dev/wd/test# df -h/dev/hda9 4.0G 148M 3.6G 4% / /dev/hda1 99M 8.3M 86M 9% /boot /dev/hda3 29G 1.1G 27G 4% /data none 252M 0 252M 0% /dev/shm /dev/hda7 9.7G 55M 9.1G 1% /home /dev/hda10 3.9G 40M 3.7G 2% /tmp /dev/hda5 9.7G 1.9G 7.4G 20% /usr /dev/hda8 7.7G 90M 7.3G 2% /var /dev/mapper/wd-test 291M 6.1M 270M 3% /optlvm的恢复 姑且就叫做恢复吧，因为我其实没有实际测试过。不过是假设我的这台电脑启动不了了，然后用knoppix尝试恢复其中的数据。 # lvmdiskscan/dev/wd/test [ 332.00 MB] /dev/ram1 [ 97.66 MB] /dev/hda1 [ 101.94 MB] /dev/ram2 [ 97.66 MB] /dev/hda2 [ 1.95 GB] /dev/ram3 [ 97.66 MB] /dev/hda3 [ 29.29 GB] /dev/ram4 [ 97.66 MB] /dev/ram5 [ 97.66 MB] /dev/hda5 [ 9.77 GB] /dev/ram6 [ 97.66 MB] /dev/hda6 [ 9.77 GB] LVM physical volume /dev/ram7 [ 97.66 MB] /dev/hda7 [ 9.77 GB] /dev/ram8 [ 97.66 MB] /dev/hda8 [ 7.81 GB] /dev/ram9 [ 97.66 MB] /dev/hda9 [ 3.97 GB] /dev/ram10 [ 97.66 MB] /dev/hda10 [ 3.91 GB] /dev/ram11 [ 97.66 MB] /dev/ram12 [ 97.66 MB] /dev/ram13 [ 97.66 MB] /dev/ram14 [ 97.66 MB] /dev/ram15 [ 97.66 MB] 1 disk 24 partitions 0 LVM physical volume whole disks 1 LVM physical volume# vgdisplay -vFinding volume group "wd" --- Volume group --- VG Name wd System ID Format lvm2 Metadata Areas 1 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 1 Act PV 1 VG Size 9.77 GB PE Size 4.00 MB Total PE 2500 Alloc PE / Size 83 / 332.00 MB Free PE / Size 2417 / 9.44 GB VG UUID NwUlxW-AmAi-LyqA-h39E-zS7q-YRj3-scZucL --- Logical volume --- LV Name /dev/wd/test VG Name wd LV UUID sPy1bM-Nz13-v0x7-bk0V-BKSH-Udzl-7ov5jM LV Write Access read/write LV Status available # open 0 LV Size 332.00 MB Current LE 83 Segments 1 Allocation inherit Read ahead sectors 0 Block device 254:0 --- Physical volumes --- PV Name /dev/hda6 PV UUID jGIjyo-lukG-LdRg-tmwe-Mgxf-09ZW-loquUZ PV Status allocatable Total PE / Free PE 2500 / 2417# vgchange -a y wd1 logical volume(s) in volume group "wd"> 这样之后就可以使用mount命令挂载/dev/wd下面的设备了。 lvm的配置在 /etc/lvm/backup 下面。 参考自 这里。