LVM Logical Volume Manager 逻辑卷管理，是Linux环境下对磁盘分区进行管理的一种机制。
下面就来实现逻辑卷的 增 删 减 测试环境 Red Hat Enterprise Linux 6.5
1 [root@localhost ~]# fdisk /dev/sdb #选择要操作的磁盘 2 Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel 3 Building a new DOS disklabel with disk identifier 0x789aa6a8. 4 Changes will remain in memory only, until you decide to write them. 5 After that, of course, the previous content won't be recoverable. 6 7 Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite) 8 9 WARNING: DOS-compatible mode is deprecated. It's strongly recommended to10 switch off the mode (command 'c') and change display units to11 sectors (command 'u').12 13 Command (m for help): p #先查看当前磁盘的分区情况，可以看到没有分区14 15 Disk /dev/sdb: 10.7 GB, 10737418240 bytes16 255 heads, 63 sectors/track, 1305 cylinders17 Units = cylinders of 16065 * 512 = 8225280 bytes18 Sector size (logical/physical): 512 bytes / 512 bytes19 I/O size (minimum/optimal): 512 bytes / 512 bytes20 Disk identifier: 0x789aa6a821 22 Device Boot Start End Blocks Id System23 24 Command (m for help): n #n 表示创建一个分区25 Command action26 e extended27 p primary partition (1-4)28 p #p 表示选择主分区类型29 Partition number (1-4): 1 #指定分区编号为130 First cylinder (1-1305, default 1): 31 Using default value 1 #指定起始扇区 默认为132 Last cylinder, +cylinders or +size{K,M,G} (1-1305, default 1305): +2G #指定大小为2G空间33 34 Command (m for help): n35 Command action36 e extended37 p primary partition (1-4)38 p 39 Partition number (1-4): 240 First cylinder (263-1305, default 263): 41 Using default value 26342 Last cylinder, +cylinders or +size{K,M,G} (263-1305, default 1305): +2G43 44 Command (m for help): t #改变分区类型45 Partition number (1-4): 1 #选择要改变的分区46 Hex code (type L to list codes): L #查看系统支持的分区47 48 0 Empty 24 NEC DOS 81 Minix / old Lin bf Solaris 49 1 FAT12 39 Plan 9 82 Linux swap / So c1 DRDOS/sec (FAT-50 2 XENIX root 3c PartitionMagic 83 Linux c4 DRDOS/sec (FAT-51 3 XENIX usr 40 Venix 80286 84 OS/2 hidden C: c6 DRDOS/sec (FAT-52 4 FAT16 <32M 41 PPC PReP Boot 85 Linux extended c7 Syrinx 53 5 Extended 42 SFS 86 NTFS volume set da Non-FS data 54 6 FAT16 4d QNX4.x 87 NTFS volume set db CP/M / CTOS / .55 7 HPFS/NTFS 4e QNX4.x 2nd part 88 Linux plaintext de Dell Utility 56 8 AIX 4f QNX4.x 3rd part 8e Linux LVM df BootIt 57 9 AIX bootable 50 OnTrack DM 93 Amoeba e1 DOS access 58 a OS/2 Boot Manag 51 OnTrack DM6 Aux 94 Amoeba BBT e3 DOS R/O 59 b W95 FAT32 52 CP/M 9f BSD/OS e4 SpeedStor 60 c W95 FAT32 (LBA) 53 OnTrack DM6 Aux a0 IBM Thinkpad hi eb BeOS fs 61 e W95 FAT16 (LBA) 54 OnTrackDM6 a5 FreeBSD ee GPT 62 f W95 Ext'd (LBA) 55 EZ-Drive a6 OpenBSD ef EFI (FAT-12/16/63 10 OPUS 56 Golden Bow a7 NeXTSTEP f0 Linux/PA-RISC b64 11 Hidden FAT12 5c Priam Edisk a8 Darwin UFS f1 SpeedStor 65 12 Compaq diagnost 61 SpeedStor a9 NetBSD f4 SpeedStor 66 14 Hidden FAT16 <3 63 GNU HURD or Sys ab Darwin boot f2 DOS secondary 67 16 Hidden FAT16 64 Novell Netware af HFS / HFS+ fb VMware VMFS 68 17 Hidden HPFS/NTF 65 Novell Netware b7 BSDI fs fc VMware VMKCORE 69 18 AST SmartSleep 70 DiskSecure Mult b8 BSDI swap fd Linux raid auto70 1b Hidden W95 FAT3 75 PC/IX bb Boot Wizard hid fe LANstep 71 1c Hidden W95 FAT3 80 Old Minix be Solaris boot ff BBT 72 1e Hidden W95 FAT173 Hex code (type L to list codes): 8e #选择对应码，这里为8e74 Changed system type of partition 1 to 8e (Linux LVM)75 76 Command (m for help): t77 Partition number (1-4): 278 Hex code (type L to list codes): 8e79 Changed system type of partition 2 to 8e (Linux LVM) #同上80 81 Command (m for help): p #再次查看分区情况82 83 Disk /dev/sdb: 10.7 GB, 10737418240 bytes84 255 heads, 63 sectors/track, 1305 cylinders85 Units = cylinders of 16065 * 512 = 8225280 bytes86 Sector size (logical/physical): 512 bytes / 512 bytes87 I/O size (minimum/optimal): 512 bytes / 512 bytes88 Disk identifier: 0x789aa6a889 90 Device Boot Start End Blocks Id System91 /dev/sdb1 1 262 2104483+ 8e Linux LVM92 /dev/sdb2 263 524 2104515 8e Linux LVM93 94 Command (m for help): w #保存修改并退出95 The partition table has been altered!96 97 Calling ioctl() to re-read partition table.98 Syncing disks. 1 [root@localhost ~]# pvcreate /dev/sdb[1,2] #创建物理卷，并指定设备 2 Physical volume "/dev/sdb1" successfully created 3 Physical volume "/dev/sdb2" successfully created 4 [root@localhost ~]# pvs #查看创建的物理卷 5 PV VG Fmt Attr PSize PFree 6 /dev/sda2 VolGroup lvm2 a-- 19.51g 0 7 /dev/sdb1 lvm2 a-- 2.01g 2.01g 8 /dev/sdb2 lvm2 a-- 2.01g 2.01g 9 [root@localhost ~]# vgcreate myvg /dev/sdb[1,2] #创建卷组，指定卷组设备为sdb1 sdb210 Volume group "myvg" successfully created11 [root@localhost ~]# vgs #查看创建成功后的卷组12 VG #PV #LV #SN Attr VSize VFree13 VolGroup 1 2 0 wz--n- 19.51g 0 14 myvg 2 0 0 wz--n- 4.01g 4.01g15 [root@localhost ~]# lvcreate -n mylv -L 2G myvg #创建逻辑卷，并指定名字为 mylv 大小为 2G16 Logical volume "mylv" created17 [root@localhost ~]# lvs #查看创建后的逻辑卷18 LV VG Attr LSize Pool Origin Data% Move Log Cpy%Sync Convert19 lv_root VolGroup -wi-ao---- 17.51g 20 lv_swap VolGroup -wi-ao---- 2.00g 21 mylv myvg -wi-a----- 2.00g
增：
顺序是从物理到逻辑卷来增加
1 [root@localhost ~]# vgextend myvg /dev/sdb3 #向卷组增加一个分区，它会自动创建物理卷 2 No physical volume label read from /dev/sdb3 3 Physical volume /dev/sdb3 not found 4 Physical volume "/dev/sdb3" successfully created 5 Volume group "myvg" successfully extended 6 [root@localhost ~]# pvs #查看物理卷多了一个sdb3 7 PV VG Fmt Attr PSize PFree 8 /dev/sda2 VolGroup lvm2 a-- 19.51g 0 9 /dev/sdb1 myvg lvm2 a-- 2.00g 4.00m10 /dev/sdb2 myvg lvm2 a-- 2.00g 2.00g11 /dev/sdb3 myvg lvm2 a-- 2.00g 2.00g12 [root@localhost ~]# vgs #查看卷组PV为3个，大小6G13 VG #PV #LV #SN Attr VSize VFree14 VolGroup 1 2 0 wz--n- 19.51g 0 15 myvg 3 1 0 wz--n- 6.01g 4.01g16 [root@localhost ~]# resize2fs -p /dev/myvg/mylv #格式化文件系统17 [root@localhost ~]# mount /dev/myvg/mylv /mnt/ #挂载逻辑卷18 [root@localhost ~]# df -lh #查看当前空间可用大小19 Filesystem Size Used Avail Use% Mounted on20 /dev/mapper/VolGroup-lv_root 18G 1.6G 15G 10% /21 tmpfs 935M 0 935M 0% /dev/shm22 /dev/sda1 485M 39M 421M 9% /boot23 /dev/mapper/myvg-mylv 2.0G 67M 1.9G 4% /mnt24 [root@localhost ~]# lvextend -L 4G /dev/myvg/mylv #扩展逻辑卷大小为4G25 Extending logical volume mylv to 4.00 GiB26 Logical volume mylv successfully resized27 [root@localhost ~]# resize2fs -p /dev/myvg/mylv #扩展文件系统，-p 为有多大就用多大28 resize2fs 1.41.12 (17-May-2010)29 Filesystem at /dev/myvg/mylv is mounted on /mnt; on-line resizing required30 old desc_blocks = 1, new_desc_blocks = 131 Performing an on-line resize of /dev/myvg/mylv to 1048576 (4k) blocks.32 The filesystem on /dev/myvg/mylv is now 1048576 blocks long.33 34 [root@localhost ~]# df -lh #再次查看可用空间35 Filesystem Size Used Avail Use% Mounted on36 /dev/mapper/VolGroup-lv_root 18G 1.6G 15G 10% /37 tmpfs 935M 0 935M 0% /dev/shm38 /dev/sda1 485M 39M 421M 9% /boot39 /dev/mapper/myvg-mylv 4.0G 68M 3.7G 2% /mnt
删：
删主要是设备的移除
1 [root@localhost ~]# vgreduce myvg /dev/sdb3 #从卷组中移除设备 2 Removed "/dev/sdb3" from volume group "myvg" 3 [root@localhost ~]# vgs #查看当前组状态 4 VG #PV #LV #SN Attr VSize VFree 5 VolGroup 1 2 0 wz--n- 19.51g 0 6 myvg 2 1 0 wz--n- 4.01g 2.01g 7 [root@localhost ~]# pvremove /dev/sdb3 #移除物理卷 8 Labels on physical volume "/dev/sdb3" successfully wiped 9 [root@localhost ~]# pvs #查看当前物理卷状态10 PV VG Fmt Attr PSize PFree11 /dev/sda2 VolGroup lvm2 a-- 19.51g 0 12 /dev/sdb1 myvg lvm2 a-- 2.00g 4.00m13 /dev/sdb2 myvg lvm2 a-- 2.00g 2.00g
减：
顺序和增是相反的
这里要注意的是，要先卸载-》强制检查-》收缩文件系统-》收缩逻辑卷-》收缩组
Logical Volume Subtract