菜鳥學習Linux LVM及配置實戰
阿新 • • 發佈：2018-10-13
linux lvm shadow back segments ive lock 如果 blog swa 每當我們生產上線服務器的時候，總是無法正確的預估磁盤大小該給多少，這樣就產生了一個技術LVM，什麽是LVM？
LVM是 Logical Volume Manager（邏輯卷管理），它是Linux環境下對磁盤分區進行管理的一種機制。
這裏菜雞哥哥畫一個圖，是我自己的理解，如果有錯誤請指正！！
那麽如何使用lvm呢？
LVM是 Logical Volume Manager（邏輯卷管理），它是Linux環境下對磁盤分區進行管理的一種機制。
這裏菜雞哥哥畫一個圖，是我自己的理解，如果有錯誤請指正！！
那麽如何使用lvm呢？
[root@jw ~]# fdisk -l Disk /dev/sda: 21.5 GB, 21474836480 bytes 255 heads, 63 sectors/track, 2610 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00009be7 Device Boot Start End Blocks Id System /dev/sda1 * 1 26 204800 83 Linux Partition 1 does not end on cylinder boundary. /dev/sda2 26 287 2097152 82 Linux swap / Solaris Partition 2 does not end on cylinder boundary. /dev/sda3 287 2611 18668544 83 Linux Disk /dev/sdb: 5368 MB, 5368709120 bytes——實驗演示使用此盤 255 heads, 63 sectors/track, 652 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0xb8acf654 Device Boot Start End Blocks Id System Disk /dev/sdc: 1073 MB, 1073741824 bytes 255 heads, 63 sectors/track, 130 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00000000 [root@jw ~]# fdisk /dev/sdb——對需要進行lvm的磁盤進行分區 WARNING: DOS-compatible mode is deprecated. It‘s strongly recommended to switch off the mode (command ‘c‘) and change display units to sectors (command ‘u‘). Command (m for help): n Command action e extended p primary partition (1-4) p Partition number (1-4): Value out of range. Partition number (1-4): 1 First cylinder (1-652, default 1): Using default value 1 Last cylinder, +cylinders or +size{K,M,G} (1-652, default 652): +1G Command (m for help): p Disk /dev/sdb: 5368 MB, 5368709120 bytes 255 heads, 63 sectors/track, 652 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0xb8acf654 Device Boot Start End Blocks Id System /dev/sdb1 1 132 1060258+ 83 Linux Command (m for help): n Command action e extended p primary partition (1-4) p Partition number (1-4): 2 First cylinder (133-652, default 133): Using default value 133 Last cylinder, +cylinders or +size{K,M,G} (133-652, default 652): +1G Command (m for help): p Disk /dev/sdb: 5368 MB, 5368709120 bytes 255 heads, 63 sectors/track, 652 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0xb8acf654 Device Boot Start End Blocks Id System /dev/sdb1 1 132 1060258+ 83 Linux /dev/sdb2 133 264 1060290 83 Linux Command (m for help): w The partition table has been altered! Calling ioctl() to re-read partition table. Syncing disks [root@jw ~]# pvcreate /dev/sdb{1,2}——創建pv Physical volume "/dev/sdb1" successfully created Physical volume "/dev/sdb2" successfully created [root@jw ~]# vgcreate vg01 /dev/sdb{1,2}——創建vg，vg名為vg01 Volume group "vg01" successfully created [root@jw ~]# lvcreate -n lv01 -L 1G vg01——創建lv，lv名為lv01，大小為1G Logical volume "lv01" created [root@jw ~]# [root@jw ~]# pvs——查看pv PV VG Fmt Attr PSize PFree /dev/sdb1 vg01 lvm2 a-- 1.01g 8.00m /dev/sdb2 vg01 lvm2 a-- 1.01g 1.01g [root@jw ~]# vgs——查看vg VG #PV #LV #SN Attr VSize VFree vg01 2 1 0 wz--n- 2.02g 1.02g [root@jw ~]# lvs——查看lv LV VG Attr LSize Pool Origin Data% Move Log Cpy%Sync Convert lv01 vg01 -wi-a----- 1.00g [root@jw ~]# [root@jw ~]# pvscan PV /dev/sdb1 VG vg01 lvm2 [1.01 GiB / 8.00 MiB free] PV /dev/sdb2 VG vg01 lvm2 [1.01 GiB / 1.01 GiB free] Total: 2 [2.02 GiB] / in use: 2 [2.02 GiB] / in no VG: 0 [0 ] [root@jw ~]# vgscan Reading all physical volumes. This may take a while... Found volume group "vg01" using metadata type lvm2 [root@jw ~]# lvscan ACTIVE ‘/dev/vg01/lv01‘ [1.00 GiB] inherit [root@jw ~]# [root@jw ~]# pvdisplay --- Physical volume --- PV Name /dev/sdb1 VG Name vg01 PV Size 1.01 GiB / not usable 3.41 MiB Allocatable yes PE Size 4.00 MiB——默認PE大小為4M Total PE 258 Free PE 2 Allocated PE 256 PV UUID CvlZqo-1Bxi-BKzg-cgGC-W7hZ-43np-SsdyEq --- Physical volume --- PV Name /dev/sdb2 VG Name vg01 PV Size 1.01 GiB / not usable 3.44 MiB Allocatable yes PE Size 4.00 MiB Total PE 258 Free PE 258 Allocated PE 0 PV UUID pDa7Mj-dCs4-cY0V-4JZY-viUG-BSNI-aspjlN [root@jw ~]# vgdisplay --- Volume group --- VG Name vg01 System ID Format lvm2 Metadata Areas 2 Metadata Sequence No 2 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 2.02 GiB PE Size 4.00 MiB Total PE 516 Alloc PE / Size 256 / 1.00 GiB Free PE / Size 260 / 1.02 GiB VG UUID FUhTIi-lmOr-eVOi-JxMA-0pMJ-yMQq-8gSlCa [root@jw ~]# lvdisplay --- Logical volume --- LV Path /dev/vg01/lv01 LV Name lv01 VG Name vg01 LV UUID S4HQMH-jxjp-0WbT-TkiV-Ftc7-dn58-7l3nsy LV Write Access read/write LV Creation host, time jw, 2017-12-22 23:06:19 +0800 LV Status available # open 0 LV Size 1.00 GiB Current LE 256 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 256 Block device 253:0 [root@jw ~]# mkfs.ext4 /dev/vg01/lv01 ——格式化lvm，文件系統為ext4 mke2fs 1.41.12 (17-May-2010) Filesystem label= OS type: Linux Block size=4096 (log=2) Fragment size=4096 (log=2) Stride=0 blocks, Stripe width=0 blocks 65536 inodes, 262144 blocks 13107 blocks (5.00%) reserved for the super user First data block=0 Maximum filesystem blocks=268435456 8 block groups 32768 blocks per group, 32768 fragments per group 8192 inodes per group Superblock backups stored on blocks: 32768, 98304, 163840, 229376 Writing inode tables: done Creating journal (8192 blocks): done Writing superblocks and filesystem accounting information: done This filesystem will be automatically checked every 36 mounts or 180 days, whichever comes first. Use tune2fs -c or -i to override. [root@jw ~]# mkdir /testlvm [root@jw ~]# mount /dev/vg01/lv01 /testlvm/ 掛載lvm [root@jw ~]# df -TH Filesystem Type Size Used Avail Use% Mounted on /dev/sda3 ext4 19G 4.7G 14G 27% / tmpfs tmpfs 515M 0 515M 0% /dev/shm /dev/sda1 ext4 204M 31M 163M 16% /boot /dev/mapper/vg01-lv01 ext4 **1.1G** 35M 969M 4% /testlvm [root@jw ~]# 這裏演示lv擴容，把/testlvm加大500M [root@jw ~]# vgs——首先查看vg是否有可用空間 VG #PV #LV #SN Attr VSize VFree——VFree還有1G空閑 vg01 2 1 0 wz--n- 2.02g 1.02g [root@jw ~]# lvextend -L +500M /dev/vg01/lv01 ——有空間直接擴展 Extending logical volume lv01 to 1.49 GiB Logical volume lv01 successfully resized [root@jw ~]# --------------------------------------------------- 如果vgs查看沒有空間，則需要添加vg,新格式化一個分區sdc1，這裏不演示格式化步驟； vgextend vg01 /dev/sdc1 Lvextend -L 500M /dev/vg01/lv01 ———————————————————— 執行以上lv擴容後，執行df -Th 發現還是沒有擴容， linux7對文件系統進行擴容執行以下命令 [root@xuegod61 ~]# xfs_growfs /dev/vg01/lv01 linux6對文件系統進行擴容執行以下命令 [root@xuegod61 ~]# resize2fs /dev/vg01/lv01 這裏演示的是格式化ext4，所以使用resize2fs [root@jw ~]# resize2fs /dev/vg01/lv01 resize2fs 1.41.12 (17-May-2010) Filesystem at /dev/vg01/lv01 is mounted on /testlvm; on-line resizing required old desc_blocks = 1, new_desc_blocks = 1 Performing an on-line resize of /dev/vg01/lv01 to 390144 (4k) blocks. The filesystem on /dev/vg01/lv01 is now 390144 blocks long. [root@jw ~]# df -TH Filesystem Type Size Used Avail Use% Mounted on /dev/sda3 ext4 19G 4.7G 14G 27% / tmpfs tmpfs 515M 0 515M 0% /dev/shm /dev/sda1 ext4 204M 31M 163M 16% /boot /dev/mapper/vg01-lv01 ext4 **1.6G** 36M 1.5G 3% /testlvm [root@jw ~]#
刪除lvm需要先umount
umount /dev/vg01/lv01
移除lv
lvremove /dev/vg01/lv01
移除vg
vgremove vg01
移除pv
pvremove /dev/sdb{1,2}
菜鳥學習Linux LVM及配置實戰