1. fdisk命令/dev/sdc再分出一个sdc2分区
[root@rhel7 ~]# fdisk /dev/sdc
Welcome to fdisk (util-linux 2.23.). Changes will remain in memory only, until you decide to write them.
Be careful before using the write command. Command (m for help): n
Partition type:
p primary ( primary, extended, free)
e extended
Select (default p): p
Partition number (-, default ):
First sector (-, default ):
Using default value
Last sector, +sectors or +size{K,M,G} (-, default ): +200M
Partition of type Linux and of size MiB is set Command (m for help): t
Partition number (,, default ):
Hex code (type L to list all codes): L Empty NEC DOS Minix / old Lin bf Solaris
FAT12 Hidden NTFS Win Linux swap / So c1 DRDOS/sec (FAT-
XENIX root Plan Linux c4 DRDOS/sec (FAT-
XENIX usr 3c PartitionMagic OS/ hidden C: c6 DRDOS/sec (FAT-
FAT16 <32M Venix Linux extended c7 Syrinx
Extended PPC PReP Boot NTFS volume set da Non-FS data
FAT16 SFS NTFS volume set db CP/M / CTOS / .
HPFS/NTFS/exFAT 4d QNX4.x Linux plaintext de Dell Utility
AIX 4e QNX4.x 2nd part 8e Linux LVM df BootIt
AIX bootable 4f QNX4.x 3rd part Amoeba e1 DOS access
a OS/ Boot Manag OnTrack DM Amoeba BBT e3 DOS R/O
b W95 FAT32 OnTrack DM6 Aux 9f BSD/OS e4 SpeedStor
c W95 FAT32 (LBA) CP/M a0 IBM Thinkpad hi eb BeOS fs
e W95 FAT16 (LBA) OnTrack DM6 Aux a5 FreeBSD ee GPT
f W95 Ext'd (LBA) 54 OnTrackDM6 a6 OpenBSD ef EFI (FAT-12/16/
OPUS EZ-Drive a7 NeXTSTEP f0 Linux/PA-RISC b
Hidden FAT12 Golden Bow a8 Darwin UFS f1 SpeedStor
Compaq diagnost 5c Priam Edisk a9 NetBSD f4 SpeedStor
Hidden FAT16 < SpeedStor ab Darwin boot f2 DOS secondary
Hidden FAT16 GNU HURD or Sys af HFS / HFS+ fb VMware VMFS
Hidden HPFS/NTF Novell Netware b7 BSDI fs fc VMware VMKCORE
AST SmartSleep Novell Netware b8 BSDI swap fd Linux raid auto
1b Hidden W95 FAT3 DiskSecure Mult bb Boot Wizard hid fe LANstep
1c Hidden W95 FAT3 PC/IX be Solaris boot ff BBT
1e Hidden W95 FAT1 Old Minix
Hex code (type L to list all codes): 8e
Changed type of partition 'Linux' to 'Linux LVM' Command (m for help): m
Command action
a toggle a bootable flag
b edit bsd disklabel
c toggle the dos compatibility flag
d delete a partition
g create a new empty GPT partition table
G create an IRIX (SGI) partition table
l list known partition types
m print this menu
n add a new partition
o create a new empty DOS partition table
p print the partition table
q quit without saving changes
s create a new empty Sun disklabel
t change a partition's system id
u change display/entry units
v verify the partition table
w write table to disk and exit
x extra functionality (experts only) Command (m for help): w
The partition table has been altered! Calling ioctl() to re-read partition table. WARNING: Re-reading the partition table failed with error : Device or resource busy.
The kernel still uses the old table. The new table will be used at
the next reboot or after you run partprobe() or kpartx()
Syncing disks. --reboot一下生效 [root@rhel7 ~]# fdisk -l /dev/sdc --查看/dev/sdc分区情况 Disk /dev/sdc: MB, bytes, sectors
Units = sectors of * = bytes
Sector size (logical/physical): bytes / bytes
I/O size (minimum/optimal): bytes / bytes
Disk label type: dos
Disk identifier: 0x0c16d904 Device Boot Start End Blocks Id System
/dev/sdc1 8e Linux LVM
/dev/sdc2 8e Linux LVM
[root@rhel7 ~]#
2.创建物理卷pv
[root@rhel7 ~]# pvcreate /dev/sdc2 #没有pvextend的说法
Physical volume "/dev/sdc2" successfully created
[root@rhel7 ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sda2 rhel lvm2 a-- .51g 40.00m
/dev/sdc1 vgdate lvm2 a-- 96.00m 4.00m
/dev/sdc2 lvm2 --- 200.00m 200.00m
[root@rhel7 ~]#
3.增加VG大小：（把上面创建的pv添加到vg里就行）
[root@rhel7 ~]# vgs
VG #PV #LV #SN Attr VSize VFree
rhel wz--n- .51g 40.00m
vgdate wz--n- 96.00m 4.00m
[root@rhel7 ~]# vgdisplay vgdate
--- Volume group ---
VG Name vgdate
System ID
Format lvm2
Metadata Areas
Metadata Sequence No
VG Access read/write
VG Status resizable
MAX LV
Cur LV
Open LV
Max PV
Cur PV
Act PV
VG Size 96.00 MiB
PE Size 4.00 MiB
Total PE
Alloc PE / Size / 92.00 MiB
Free PE / Size / 4.00 MiB
VG UUID hNTqaY-c0Hi-v5wk-p7lQ-TIbc-oSpm-TIOcHs [root@rhel7 ~]# vgextend vgdate /dev/sdc2 ---向卷组vgdata中添加pv。没有加多少M或多少G进来的说法，只能把整个PV添加到卷组中来。
Volume group "vgdate" successfully extended
[root@rhel7 ~]# vgs
VG #PV #LV #SN Attr VSize VFree
rhel wz--n- .51g 40.00m
vgdate wz--n- 292.00m 200.00m
[root@rhel7 ~]# vgdisplay vgdate
--- Volume group ---
VG Name vgdate
System ID
Format lvm2
Metadata Areas
Metadata Sequence No
VG Access read/write
VG Status resizable
MAX LV
Cur LV
Open LV
Max PV
Cur PV
Act PV
VG Size 292.00 MiB
PE Size 4.00 MiB
Total PE
Alloc PE / Size / 92.00 MiB
Free PE / Size / 200.00 MiB
VG UUID hNTqaY-c0Hi-v5wk-p7lQ-TIbc-oSpm-TIOcHs [root@rhel7 ~]#
4.增加LV的大小
[root@rhel7 ~]# lvdisplay vgdate
--- Logical volume ---
LV Path /dev/vgdate/lvvol1
LV Name lvvol1
VG Name vgdate
LV UUID dt10du-dTAJ-0gUV-LqrO-wRUY-rb5h-171DCr
LV Write Access read/write
LV Creation host, time rhel7.com, -- :: -
LV Status available
# open
LV Size 92.00 MiB
Current LE
Segments
Allocation inherit
Read ahead sectors auto
- currently set to
Block device : [root@rhel7 ~]# lvextend -L+200MB /dev/vgdate/lvvol1 --给逻辑卷lvvol1增加200MB的空间。如果写成-L 200M，则表示把逻辑卷扩大至200M。
或者lvextend /dev/vgdate/lvvol1 /dev/sdc2 将把/dev/sdc2这个pv剩余的所有空间都分配给逻辑卷lvvol1。
Size of logical volume vgdate/lvvol1 changed from 92.00 MiB ( extents) to 292.00 MiB ( extents).
Logical volume lvvol1 successfully resized.
[root@rhel7 ~]# lvdisplay vgdate
--- Logical volume ---
LV Path /dev/vgdate/lvvol1
LV Name lvvol1
VG Name vgdate
LV UUID dt10du-dTAJ-0gUV-LqrO-wRUY-rb5h-171DCr
LV Write Access read/write
LV Creation host, time rhel7.com, -- :: -
LV Status available
# open
LV Size 292.00 MiB ---LV size已增加至292MB
Current LE
Segments
Allocation inherit
Read ahead sectors auto
- currently set to
Block device : [root@rhel7 ~]#
也可以使用lvresize命令来增加lv的大小：
■lvresize -r -l 75%VG /dev/vgdata/lvdata This resizes the logical volume so that it will take 75% of the total disk space in the volume group.
■ lvresize -r -l +75%VG /dev/vgdata/lvdata This tries to add 75% of the total size of the volume group to the logical volume. (Notice the difference with the previous command.)
■ lvresize -r -l +75%FREE /dev/vgdata/lvdata This adds 75% of all free disk space to the logical volume.
■ lvresize -r -l 75%FREE /dev/vgdata/lvdata This resizes the logical volume to a total size that equals 75% of the amount of free disk space. (Notice the difference with the previous command.)
5. 增加了逻辑卷的容量以后，就需要修改文件系统大小以实现利用扩充的空间
从上面可以看到，虽然LV大小已增加至292MB，但是使用df -hT命令查看到的文件系统/dev/mapper/vgdate-lvvol1的大小没变，还是89M，所以还需要修改文件系统的大小才可以使用扩充的空间。
[root@rhel7 ~]# df -hT
Filesystem Type Size Used Avail Use% Mounted on
/dev/mapper/rhel-root xfs 18G .5G 13G % /
devtmpfs devtmpfs 911M 911M % /dev
tmpfs tmpfs 921M 921M % /dev/shm
tmpfs tmpfs 921M 8.4M 912M % /run
tmpfs tmpfs 921M 921M % /sys/fs/cgroup
/dev/mapper/vgdate-lvvol1 xfs 89M 4.8M 84M 6% /lvmFiles
/dev/sdd1 xfs 497M 124M 374M % /boot
tmpfs tmpfs 185M 185M % /run/user/
使用xfs_growfs命令扩展文件系统。注意这个命令只能用来扩展xfs格式的文件系统，xfs格式是RHEL7版本默认的文件系统，所以用得比较少。
DESCRIPTION
xfs_growfs expands an existing XFS filesystem (see xfs()). The mount-point argument is the pathname of the directory where the
filesystem is mounted. The filesystem must be mounted to be grown (see mount()). The existing contents of the filesystem are undis‐
turbed, and the added space becomes available for additional file storage.
还有另外一个命令resize2fs也是用来扩展文件系统，但是只能用来扩展ext2,ext3,ext4格式的文件系统大小，在RHEL7版本以下的系统中用得比较多。
[root@rhel7 ~]# man resize2fs
RESIZE2FS() System Manager's Manual RESIZE2FS(8) NAME
resize2fs - ext2/ext3/ext4 file system resizer SYNOPSIS
resize2fs [ -fFpPM ] [ -d debug-flags ] [ -S RAID-stride ] device [ size ] DESCRIPTION
The resize2fs program will resize ext2, ext3, or ext4 file systems. It can be used to enlarge or shrink an unmounted file system
located on device. If the filesystem is mounted, it can be used to expand the size of the mounted filesystem, assuming the kernel sup‐
ports on-line resizing.
如果在xfs格式的文件系统中使用resize2fs命令，则会报如下错误：
[root@rhel7 ~]# resize2fs /dev/mapper/vgdate-lvvol1
resize2fs 1.42. (-Dec-)
resize2fs: Bad magic number in super-block while trying to open /dev/mapper/vgdate-lvvol1
Couldn't find valid filesystem superblock.
[root@rhel7 ~]# resize2fs -f /dev/mapper/vgdate-lvvol1
resize2fs 1.42. (-Dec-)
resize2fs: Bad magic number in super-block while trying to open /dev/mapper/vgdate-lvvol1
Couldn't find valid filesystem superblock.
使用xfs_growfs命令扩展文件系统大小：
[root@rhel7 ~]# xfs_growfs /dev/mapper/vgdate-lvvol1
meta-data=/dev/mapper/vgdate-lvvol1 isize= agcount=, agsize= blks
= sectsz= attr=, projid32bit=
= crc= finobt=
data = bsize= blocks=, imaxpct=
= sunit= swidth= blks
naming =version bsize= ascii-ci= ftype=
log =internal bsize= blocks=, version=
= sectsz= sunit= blks, lazy-count=
realtime =none extsz= blocks=, rtextents=
data blocks changed from to
[root@rhel7 ~]# df -hT
Filesystem Type Size Used Avail Use% Mounted on
/dev/mapper/rhel-root xfs 18G .5G 13G % /
devtmpfs devtmpfs 911M 911M % /dev
tmpfs tmpfs 921M 921M % /dev/shm
tmpfs tmpfs 921M 8.4M 912M % /run
tmpfs tmpfs 921M 921M % /sys/fs/cgroup
/dev/mapper/vgdate-lvvol1 xfs 289M 5.1M 284M % /lvmFiles ----------已扩展完成
/dev/sdd1 xfs 497M 124M 374M % /boot
tmpfs tmpfs 185M 185M % /run/user/