Linux Cache

使用fdisk列表磁盘设备

 [root@oracle ~]# fdisk -l

Disk /dev/sda: 107.4 GB, 107374182400 bytes
 255 heads, 63 sectors/track, 13054 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: 0x00013e83

Device Boot Start End Blocks Id System
 /dev/sda1 * 1 64 512000 83 Linux
 Partition 1 does not end on cylinder boundary.
 /dev/sda2 64 13055 104344576 8e Linux LVM

Disk /dev/sdb: 10.7 GB, 10737418240 bytes
 255 heads, 63 sectors/track, 1305 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

Disk /dev/mapper/vg_oracle-lv_root: 53.7 GB, 53687091200 bytes
 255 heads, 63 sectors/track, 6527 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

Disk /dev/mapper/vg_oracle-lv_swap: 4227 MB, 4227858432 bytes
 255 heads, 63 sectors/track, 514 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

Disk /dev/mapper/vg_oracle-lv_home: 48.9 GB, 48930750464 bytes
 255 heads, 63 sectors/track, 5948 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@oracle ~]#

整块磁盘作为物理卷使用，必须清除已有分区表信息

创建物理卷

 [root@oracle ~]# pvcreate /dev/sdb
 Writing physical volume data to disk "/dev/sdb"
 Physical volume "/dev/sdb" successfully created
 [root@oracle ~]#

扫描用作物理卷的块设备

 [root@oracle ~]# lvmdiskscan
 /dev/ram0 [ 16.00 MiB]
 /dev/root [ 50.00 GiB]
 /dev/ram1 [ 16.00 MiB]
 /dev/sda1 [ 500.00 MiB]
 /dev/vg_oracle/lv_swap [ 3.94 GiB]
 /dev/ram2 [ 16.00 MiB]
 /dev/sda2 [ 99.51 GiB] LVM physical volume
 /dev/vg_oracle/lv_home [ 45.57 GiB]
 /dev/ram3 [ 16.00 MiB]
 /dev/ram4 [ 16.00 MiB]
 /dev/ram5 [ 16.00 MiB]
 /dev/ram6 [ 16.00 MiB]
 /dev/ram7 [ 16.00 MiB]
 /dev/ram8 [ 16.00 MiB]
 /dev/ram9 [ 16.00 MiB]
 /dev/ram10 [ 16.00 MiB]
 /dev/ram11 [ 16.00 MiB]
 /dev/ram12 [ 16.00 MiB]
 /dev/ram13 [ 16.00 MiB]
 /dev/ram14 [ 16.00 MiB]
 /dev/ram15 [ 16.00 MiB]
 /dev/sdb [ 10.00 GiB] LVM physical volume
 3 disks
 17 partitions
 1 LVM physical volume whole disk
 1 LVM physical volume
 [root@oracle ~]#

显示物理卷属性

 [root@oracle ~]# pvs
 PV VG Fmt Attr PSize PFree
 /dev/sda2 vg_oracle lvm2 a-- 99.51g 0
 /dev/sdb lvm2 a-- 10.00g 10.00g

显示物理卷详细参数
[root@oracle ~]# pvdisplay
— Physical volume —
PV Name /dev/sda2
VG Name vg_oracle
PV Size 99.51 GiB / not usable 3.00 MiB
Allocatable yes (but full)
PE Size 4.00 MiB
Total PE 25474
Free PE 0
Allocated PE 25474
PV UUID JdCNKZ-Rkhn-yU3I-b90L-PsBA-OeWh-eFKRxo

“/dev/sdb” is a new physical volume of “10.00 GiB”
— NEW Physical volume —
PV Name /dev/sdb
VG Name
PV Size 10.00 GiB
Allocatable NO
PE Size 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID vXmWfe-qy80-PLkB-4OP1-XG7z-d2h5-XoMu7W

[root@oracle ~]# pvscan
PV /dev/sda2 VG vg_oracle lvm2 [99.51 GiB / 0 free]
PV /dev/sdb lvm2 [10.00 GiB]
Total: 2 [109.51 GiB] / in use: 1 [99.51 GiB] / in no VG: 1 [10.00 GiB]
[root@oracle ~]#

删除物理卷（如果物理卷已加入卷组，则需要先从卷组中删除此物理卷）
[root@oracle ~]# pvremove /dev/sdb
Labels on physical volume “/dev/sdb” successfully wiped

————————————————

创建卷组

 #vgcreate vg1 /dev/sdb /dev/sdc

在当前卷组中添加物理卷

 [root@oracle ~]# pvscan
 PV /dev/sda2 VG vg_oracle lvm2 [99.51 GiB / 0 free]
 PV /dev/sdb lvm2 [10.00 GiB]
 Total: 2 [109.51 GiB] / in use: 1 [99.51 GiB] / in no VG: 1 [10.00 GiB]
 [root@oracle ~]# vgextend vg_oracle /dev/sdb
 Volume group "vg_oracle" successfully extended
 [root@oracle ~]# pvscan
 PV /dev/sda2 VG vg_oracle lvm2 [99.51 GiB / 0 free]
 PV /dev/sdb VG vg_oracle lvm2 [10.00 GiB / 10.00 GiB free]
 Total: 2 [109.50 GiB] / in use: 2 [109.50 GiB] / in no VG: 0 [0 ]
 [root@oracle ~]#

查看卷组信息

 [root@oracle ~]# vgs
 VG #PV #LV #SN Attr VSize VFree
 vg_oracle 2 3 0 wz--n- 109.50g 10.00g
 [root@oracle ~]# vgdisplay
 --- Volume group ---
 VG Name vg_oracle
 System ID
 Format lvm2
 Metadata Areas 2
 Metadata Sequence No 5
 VG Access read/write
 VG Status resizable
 MAX LV 0
 Cur LV 3
 Open LV 3
 Max PV 0
 Cur PV 2
 Act PV 2
 VG Size 109.50 GiB
 PE Size 4.00 MiB
 Total PE 28033
 Alloc PE / Size 25474 / 99.51 GiB
 Free PE / Size 2559 / 10.00 GiB
 VG UUID O3uWt8-me7n-8vrZ-fcO2-5Z6b-SUse-e0llmJ

[root@oracle ~]#

从卷组中删除物理卷
[root@oracle ~]# vgreduce vg_oracle /dev/sdb
Removed “/dev/sdb” from volume group “vg_oracle”

[root@oracle ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sda2 vg_oracle lvm2 a– 99.51g 0
/dev/sdb lvm2 a– 10.00g 10.00g
[root@oracle ~]# vgs
VG #PV #LV #SN Attr VSize VFree
vg_oracle 1 3 0 wz–n- 99.51g 0
[root@oracle ~]#

删除（不包含逻辑卷的）卷组
[root@oracle ~]# vgremove vg1-new
Volume group “vg1-new” successfully removed
[root@oracle ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sda2 vg_oracle lvm2 a– 99.51g 0
/dev/sdb lvm2 a– 10.00g 10.00g
[root@oracle ~]#

分割卷组
[root@oracle ~]# vgsplit vg_oracle new_vg /dev/sdb
New volume group “new_vg” successfully split from “vg_oracle”
[root@oracle ~]# vgs
VG #PV #LV #SN Attr VSize VFree
new_vg 1 0 0 wz–n- 10.00g 10.00g
vg_oracle 1 3 0 wz–n- 99.51g 0
[root@oracle ~]#

合并卷组
[root@oracle ~]# vgmerge -v vg_oracle new_vg
Checking for volume group “new_vg”
Checking for volume group “vg_oracle”
Archiving volume group “new_vg” metadata (seqno 2).
Archiving volume group “vg_oracle” metadata (seqno 8).
Writing out updated volume group
Creating volume group backup “/etc/lvm/backup/vg_oracle” (seqno 9).
Volume group “new_vg” successfully merged into “vg_oracle”
[root@oracle ~]# vgs
VG #PV #LV #SN Attr VSize VFree
vg_oracle 2 3 0 wz–n- 109.50g 10.00g
[root@oracle ~]#

重命名卷组
[root@oracle ~]# vgcreate vg1 /dev/sdb
Volume group “vg1” successfully created
[root@oracle ~]# vgs
VG #PV #LV #SN Attr VSize VFree
vg1 1 0 0 wz–n- 10.00g 10.00g
vg_oracle 1 3 0 wz–n- 99.51g 0
[root@oracle ~]# vgrename vg1 vg1-new
Volume group “vg1” successfully renamed to “vg1-new”
[root@oracle ~]# vgs
VG #PV #LV #SN Attr VSize VFree
vg1-new 1 0 0 wz–n- 10.00g 10.00g
vg_oracle 1 3 0 wz–n- 99.51g 0
[root@oracle ~]#

————————————————

逻辑卷的三种类型：线性卷，条状卷，镜像卷

创建指定大小的逻辑卷分区
[root@oracle ~]# lvcreate -L 6G -n new_vg-lv_01 new_vg
Logical volume “new_vg-lv_01” created

查看创建的逻辑卷
#lvs
LV VG Attr LSize Pool Origin Data% Move Log Copy% Convert
new_vg-lv_01 new_vg -wi-a— 6.00g
lv_home vg_oracle -wi-ao– 41.57g
lv_root vg_oracle -wi-ao– 50.00g
lv_swap vg_oracle -wi-ao– 3.94g
[root@oracle ~]#

对逻辑卷进行格式化
[root@oracle ~]# mkfs.ext4 /dev/new_vg/new_vg-lv_01
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
393216 inodes, 1572864 blocks
78643 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=1610612736
48 block groups
32768 blocks per group, 32768 fragments per group
8192 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 23 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
[root@oracle ~]#

查看逻辑卷信息
[root@oracle ~]# lvscan
ACTIVE ‘/dev/new_vg/new_vg-lv_01’ [6.00 GiB] inherit
ACTIVE ‘/dev/vg_oracle/lv_root’ [50.00 GiB] inherit
ACTIVE ‘/dev/vg_oracle/lv_home’ [41.57 GiB] inherit
ACTIVE ‘/dev/vg_oracle/lv_swap’ [3.94 GiB] inherit
[root@oracle ~]#

查看逻辑卷参数信息
#lvdisplay

增大逻辑卷
[root@oracle ~]# lvextend -L +1G /dev/new_vg/new_vg-lv_01
Extending logical volume new_vg-lv_01 to 7.00 GiB
Logical volume new_vg-lv_01 successfully resized

增大逻辑卷后更新文件系统
[root@oracle ~]# resize2fs /dev/new_vg/new_vg-lv_01
resize2fs 1.41.12 (17-May-2010)
Resizing the filesystem on /dev/new_vg/new_vg-lv_01 to 1835008 (4k) blocks.
The filesystem on /dev/new_vg/new_vg-lv_01 is now 1835008 blocks long.

[root@oracle ~]#

删除逻辑卷
[root@oracle ~]# lvremove /dev/new_vg/new_vg-lv_01
Do you really want to remove active logical volume new_vg-lv_01? [y/n]: y
Logical volume “new_vg-lv_01” successfully removed
[root@oracle ~]#

挂载逻辑卷
[root@oracle ~]# mount /dev/new_vg/new_vg-lv_01 /new/
[root@oracle ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg_oracle-lv_root
50G 13G 35G 27% /
tmpfs 939M 492M 448M 53% /dev/shm
/dev/sda1 485M 54M 406M 12% /boot
/dev/mapper/vg_oracle-lv_home
45G 2.6G 41G 7% /home
/dev/mapper/new_vg-new_vg–lv_01
2.0G 67M 1.9G 4% /new
[root@oracle ~]#

自动挂载文件系统
#vi /etc/fstab
/dev/new_vg/new_vg-lv_01 /new ext4 default 0 0