LVM resizing method

The biggest advantage of LVM is that it can elastically adjust the file system capacity online. There is an active LV with a capacity of 100 MB. Now we are ready to resize this partition (note that the entire resizing operation is directly online without restarting) [root @ kashu ~] # Df-hT | grepkashu/dev/mapper/kashuVG-kashuLVext

The biggest advantage of LVM is yes.Online modeElastically adjusts the capacity of the file system.

There is an active LV with a capacity of 100 MB. Now we are ready to resize this partition (note that the entire resizing operation is directly online without restarting)

[Root @ kashu ~] # Df-hT | grep kashu

/Dev/mapper/kashuVG-kashuLV ext497 M5.6 M, 87 M, 7%/mnt/kashuLV

First, check the number of remaining PES in the VG where the LV is located, and find that there are many idle PES (229 idle PES ), then we can directly expand the remaining capacity of the VG to the existing LV.

[Root @ kashu ~] # Vgdisplay kashuVG

--- Volume group ---

VG Name kashuVG

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 1

Max PV 0

Cur PV 2

Act PV 2

VG Size 1016.00 MiB

PE Size 4.00 MiB

Total PE 254

Alloc PE/Size 25/100 .00 MiB

Free PE/Size 229/916 .00MiB

Vg uuid aWVKcm-2Z0m-S2d4-TDeg-m3g9-PWa8-3g7NzJ

For example, increase the original LV capacity by 100 MB.

[Root @ kashu ~] #Lvresize-L + 100 M/dev/kashuVG/kashuLV

Extending logical volume kashuLV to 200.00 MiB

Logical volume kashuLV successfully resized

After completing the above operations, we can immediately check the capacity of this LV, which has changed to 200 MB.

[Root @ kashu ~] #Lvdisplay/dev/kashuVG/kashuLV

--- Logical volume ---

LV Path/dev/kashuVG/kashuLV

LV Name kashuLV

VG Name kashuVG

Lvuuid RF3XbP-oEma-nWPE-X21d-4d9n-9spr-NYFfUq

LV Write Access read/write

LV Creation host, time kashu. localdomain, 2013-05-0700: 34: 37-0400

LV Status available

# Open 1

LV Size 200.00 MiB

Current LE 50

Segments 1

Allocation inherit

Read ahead sectors auto

-Currently sets to 256

Block device 253: 2

However, note that the available capacity of the real file system does not automatically increase. you will find that the partition is still 100 MB.

[Root @ kashu ~] #Df-hT | grep kashu

/Dev/mapper/kashuVG-kashuLV ext497 M5.6 M, 87 M, 7%/mnt/kashuLV

Therefore, we must also update the file system capacity through resize2fs:

[Root @ kashu ~] #Resize2fs/dev/kashuVG/kashuLV

Resize2fs 1.41.12 (17-May-2010)

Filesystem at/dev/kashuVG/kashuLV is mounted on/mnt/kashuLV; on-line resizing required

Old desc_blocks = 1, new_desc_blocks = 1

Ming an on-line resize of/dev/kashuVG/kashuLV to 204800 (1 k) blocks.

The filesystem on/dev/kashuVG/kashuLV is now 204800 blockslong.

Now, let's look at the partition and find that it has changed to MB. the expansion is successful!

[Root @ kashu ~] #Df-hT | grep kashu

/Dev/mapper/kashuVG-kashuLV ext4200 M5.6 M, 87 M, 7%/mnt/kashuLV

Well, the above LVM resizing is performed in the original VG with a lot of remaining PEs. what if the VG has no remaining PES? Next, let's give it a try.

The current kashuVG vg has no PE left.

[Root @ kashu ~] #Vgdisplay kashuVG

--- Volume group ---

VG Name kashuVG

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 1016.00 MiB

PE Size 4.00 MiB

Total PE 254

Alloc PE/Size 254/1016 .00MiB

Free PE/Size 0/0

Vg uuid ZoDB2j-BygB-m4lC-0Ntd-KRRs-WGHW-Z4NFph

The VG consists of the/dev/sdb5 and/dev/sdb6 PVS.

[Root @ kashu ~] #Pvscan

PVS/dev/sdb5 VG kashuVG lvm2 [508.00 MiB/0 free]

PVS/dev/sdb6 VG kashuVG lvm2 [508.00 MiB/0 free]

PV/dev/sda2 VG VolGroup lvm2 [19.51 GiB/0 free]

Total: 3 [20.50 GiB]/in use: 3 [20.50 GiB]/in no VG: 0 [0]

Now, the partition is only 1 GB.

[Root @ kashu ~] #Df-hT | grep kashu

/Dev/mapper/kashuVG-kashuLV ext4 1001 M 18 M 932 M 2%/mnt/kashuLV

Okay. start resizing. First create a PV

[Root @ kashu ~] #Pvcreate/dev/sdb7

Writing physical volume data to disk "/dev/sdb7"

Physical volume "/dev/sdb7" successfully created

Check that a PV named/dev/sdb7 is larger than 1 GB.

[Root @ kashu ~] #Pvscan

PVS/dev/sdb5 VG kashuVG lvm2 [508.00 MiB/0 free]

PVS/dev/sdb6 VG kashuVG lvm2 [508.00 MiB/0 free]

PV/dev/sda2 VG VolGroup lvm2 [19.51 GiB/0 free]

PV/dev/sdb7 lvm2 [1.01 GiB]

Total: 4 [21.51 GiB]/in use: 3 [20.50 GiB]/in no VG: 1 [1.01 GiB]

Then, expand the new PV to the VG.

[Root @ kashu ~] #Vgextend kashuVG/dev/sdb7

Volume group "kashuVG" successfully extended

Check that the PV/dev/sdb7 has been added to the VG of kashuVG.

[Root @ kashu ~] #Pvscan

PV/dev/sdb5 VG kashuVG lvm2 [508.00MiB/0 free]

PV/dev/sdb6 VG kashuVG lvm2 [508.00MiB/0 free]

PV/dev/sdb7 VG kashuVG lvm2 [1.01GiB/1.01 GiB free]

PV/dev/sda2 VG VolGroup lvm2 [19.51 GiB/0 free]

Total: 4 [21.51 GiB]/in use: 4 [21.51 GiB]/in no VG: 0 [0]

In addition, the VG of kashuVG has changed from 1 GB to 2 GB, with 258 idle PES.

[Root @ kashu ~] #Vgdisplay kashuVG

--- Volume group ---

VG NameKashuVG

System ID

Format lvm2

Metadata Areas 3

Metadata Sequence No 3

VG Access read/write

VG Status resizable

Max lv 0

Cur LV 1

Open LV 1

Max PV 0

Cur PV 3

Act PV 3

VG Size 2.00 GiB

PE Size 4.00 MiB

Total PE 512

Alloc PE/Size 254/1016 .00MiB

Free PE/Size 258/1 .01GiB

Vg uuid ZoDB2j-BygB-m4lC-0Ntd-KRRs-WGHW-Z4NFph

Then resize the LV, and add 258 PES to this kashuLV (you can also use-L +NG to specify the capacity)

[Root @ kashu ~] #Lvresize-l + 258/dev/kashuVG/kashuLV

Extending logical volume kashuLV to 2.00 GiB

Logical volume kashuLV successfully resized

After the above operations, the actual file system capacity does not automatically grow! It's still 1 GB!

[Root @ kashu ~] #Df-hT | grep kashu

/Dev/mapper/kashuVG-kashuLV ext41001 M18 M 932 M 2%/mnt/kashuLV

Therefore, we must not forget to use resize2fs to fully scale up the capacity to the file system!

[Root @ kashu ~] #Resize2fs/dev/kashuVG/kashuLV

Resize2fs 1.41.12 (17-May-2010)

Filesystem at/dev/kashuVG/kashuLV is mounted on/mnt/kashuLV; on-line resizing required

Old desc_blocks = 1, new_desc_blocks = 1

Ming an on-line resize of/dev/kashuVG/kashuLV to 524288 (4 k) blocks.

The filesystem on/dev/kashuVG/kashuLV is now 524288 blockslong.

Now, let's take a look at this partition, which also increases to 2 GB. This completes the expansion!

[Root @ kashu ~] #Df-hT | grep kashu

/Dev/mapper/kashuVG-kashuLV ext42.0 GB18 M 1.9 GB 1%/mnt/kashuLV