Shulou(Shulou.com)06/01 Report--

In this issue, the editor will bring you about how to reduce the usage space of the / home directory and create a new LVM. The article is rich in content and analyzes and narrates it from a professional point of view. I hope you can get something after reading this article.

Display physical volumes:

[root@jing1 ~] # pvdisplay

-Physical volume

PV Name / dev/sda2

VG Name vg_jing1

PV Size 299.51 GiB / not usable 3.00 MiB

Allocatable yes

PE Size 4.00 MiB

Total PE 76674

Free PE 142

Allocated PE 76532

PV UUID fusHvY-5mpq-X2bO-pbdC-2AWl-m4wO-cUf07p

View disk mount:

[root@jing1] # df-h

Filesystem Size Used Avail Use% Mounted on

/ dev/mapper/vg_jing1-lv_root 231G 27G 193G 13% /

Tmpfs 16G 228K 16G 1% / dev/shm

/ dev/sda1 485m 39m 421m 9% / boot

/ dev/mapper/vg_jing1-lv_home 49G 226M 46G 1% / home

/ dev/sr0 3.6G 3.6G 0100% / media/RHEL_6.5 x861464 Disc 1

Umount home directory:

[root@jing1 /] # umount / home

Check lvm:

[root@jing1 /] # e2fsck-f / dev/vg_jing1/lv_home

E2fsck 1.41.12 (17-May-2010)

Pass 1: Checking inodes, blocks, and sizes

Pass 2: Checking directory structure

Pass 3: Checking directory connectivity

Pass 4: Checking reference counts

Pass 5: Checking group summary information

/ dev/vg_jing1/lv_home: 504 files 3203072 (0.0% non-contiguous), 258764 blocks blocks

Resize lvm (be careful not to use in a production environment):

[root@jing1 /] # resize2fs / dev/vg_jing1/lv_home 2G

Resize2fs 1.41.12 (17-May-2010)

Resizing the filesystem on / dev/vg_jing1/lv_home to 524288 (4k) blocks.

The filesystem on / dev/vg_jing1/lv_home is now 524288 blocks long.

Reduce lvm space:

[root@jing1 /] # lvreduce-L 2G / dev/vg_jing1/lv_home

WARNING: Reducing active logical volume to 2.00 GiB

THIS MAY DESTROY YOUR DATA (filesystem etc.)

Do you really want to reduce lv_home? [y/n]: y

Reducing logical volume lv_home to 2.00 GiB

Logical volume lv_home successfully resized

Remount the / home directory

[root@jing1 /] # mount / dev/vg_jing1/lv_home / home

[root@jing1 /] # df-h

Filesystem Size Used Avail Use% Mounted on

/ dev/mapper/vg_jing1-lv_root 231G 27G 193G 13% /

Tmpfs 16G 228K 16G 1% / dev/shm

/ dev/sda1 485m 39m 421m 9% / boot

/ dev/sr0 3.6G 3.6G 0100% / media/RHEL_6.5 x861464 Disc 1

/ dev/mapper/vg_jing1-lv_home 2.0G 198M 1.7G 11% / home

[root@jing1 /] # fdisk-l

Disk / dev/sda: 322.1 GB, 322122547200 bytes

255 heads, 63 sectors/track, 39162 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

Sector size (logical/physical): 512 bytes / 512 bytes

I size (minimum/optimal): 512 bytes / 512 bytes

Disk identifier: 0x000ba939

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 39163 314059776 8e Linux LVM

Disk / dev/mapper/vg_jing1-lv_root: 251.7 GB, 251658240000 bytes

255 heads, 63 sectors/track, 30595 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

Sector size (logical/physical): 512 bytes / 512 bytes

I size (minimum/optimal): 512 bytes / 512 bytes

Disk identifier: 0x00000000

Disk / dev/mapper/vg_jing1-lv_swap: 16.9 GB, 16911433728 bytes

255 heads, 63 sectors/track, 2056 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

Sector size (logical/physical): 512 bytes / 512 bytes

I size (minimum/optimal): 512 bytes / 512 bytes

Disk identifier: 0x00000000

Disk / dev/mapper/vg_jing1-lv_home: 2147 MB, 2147483648 bytes

255 heads, 63 sectors/track, 261 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

Sector size (logical/physical): 512 bytes / 512 bytes

I size (minimum/optimal): 512 bytes / 512 bytes

Disk identifier: 0x00000000

Space is freed into the physical volume:

[root@jing1 /] # pvdisplay

-Physical volume

PV Name / dev/sda2

VG Name vg_jing1

PV Size 299.51 GiB / not usable 3.00 MiB

Allocatable yes

PE Size 4.00 MiB

Total PE 76674

Free PE 12130

Allocated PE 64544

PV UUID fusHvY-5mpq-X2bO-pbdC-2AWl-m4wO-cUf07p

Look at the volume group and find that the reduced space has been automatically released to the volume group:

[root@jing1 /] # vgdisplay

-Volume group

VG Name vg_jing1

System ID

Format lvm2

Metadata Areas 1

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 1

Act PV 1

VG Size 299.51 GiB

PE Size 4.00 MiB

Total PE 76674

Alloc PE / Size 64544 / 252.12 GiB

Free PE / Size 12130 / 47.38 GiB

VG UUID 1IW8eG-arlp-kvje-wFLT-pC5d-AcY0-RulpNe

Create a lvm named lv_test:

[root@jing1 /] # lvcreate-L 15G-n lv_test vg_jing1

Logical volume "lv_test" created

[root@jing1 /] # lvdisplay

-Logical volume

LV Path / dev/vg_jing1/lv_root

LV Name lv_root

VG Name vg_jing1

LV UUID shkBg6-9RqZ-AhDG-qfVf-d51Z-nsoS-qvF7Da

LV Write Access read/write

LV Creation host, time jing1, 2017-02-10 10:33:09 + 0800

LV Status available

# open 1

LV Size 234.38 GiB

Current LE 60000

Segments 1

Allocation inherit

Read ahead sectors auto

-currently set to 256

Block device 253:0

-Logical volume

LV Path / dev/vg_jing1/lv_swap

LV Name lv_swap

VG Name vg_jing1

LV UUID FQE8o0-yOKG-S4ip-Cvry-qSdk-v3f9-uPSa1e

LV Write Access read/write

LV Creation host, time jing1, 2017-02-10 10:33:50 + 0800

LV Status available

# open 1

LV Size 15.75 GiB

Current LE 4032

Segments 1

Allocation inherit

Read ahead sectors auto

-currently set to 256

Block device 253:1

-Logical volume

LV Path / dev/vg_jing1/lv_home

LV Name lv_home

VG Name vg_jing1

LV UUID FTLjIk-zr5B-M5ak-WdXB-c2Zs-c0eC-xZ6YBp

LV Write Access read/write

LV Creation host, time jing1, 2017-02-10 10:33:51 + 0800

LV Status available

# open 1

LV Size 2.00 GiB

Current LE 512

Segments 1

Allocation inherit

Read ahead sectors auto

-currently set to 256

Block device 253:2

-Logical volume

LV Path / dev/vg_jing1/lv_test

LV Name lv_test

VG Name vg_jing1

LV UUID l1IhX5-LOKf-lOaH-K5nZ-3wod-2X7m-07cogG

LV Write Access read/write

LV Creation host, time jing1, 2017-11-28 13:19:39 + 0800

LV Status available

# open 0

LV Size 15.00 GiB

Current LE 3840

Segments 1

Allocation inherit

Read ahead sectors auto

-currently set to 256

Block device 253:3

[root@jing1 /] # lvdisplay

-Logical volume

LV Path / dev/vg_jing1/lv_root

LV Name lv_root

VG Name vg_jing1

LV UUID shkBg6-9RqZ-AhDG-qfVf-d51Z-nsoS-qvF7Da

LV Write Access read/write

LV Creation host, time jing1, 2017-02-10 10:33:09 + 0800

LV Status available

# open 1

LV Size 234.38 GiB

Current LE 60000

Segments 1

Allocation inherit

Read ahead sectors auto

-currently set to 256

Block device 253:0

-Logical volume

LV Path / dev/vg_jing1/lv_swap

LV Name lv_swap

VG Name vg_jing1

LV UUID FQE8o0-yOKG-S4ip-Cvry-qSdk-v3f9-uPSa1e

LV Write Access read/write

LV Creation host, time jing1, 2017-02-10 10:33:50 + 0800

LV Status available

# open 1

LV Size 15.75 GiB

Current LE 4032

Segments 1

Allocation inherit

Read ahead sectors auto

-currently set to 256

Block device 253:1

-Logical volume

LV Path / dev/vg_jing1/lv_home

LV Name lv_home

VG Name vg_jing1

LV UUID FTLjIk-zr5B-M5ak-WdXB-c2Zs-c0eC-xZ6YBp

LV Write Access read/write

LV Creation host, time jing1, 2017-02-10 10:33:51 + 0800

LV Status available

# open 1

LV Size 2.00 GiB

Current LE 512

Segments 1

Allocation inherit

Read ahead sectors auto

-currently set to 256

Block device 253:2

-Logical volume

LV Path / dev/vg_jing1/lv_test

LV Name lv_test

VG Name vg_jing1

LV UUID l1IhX5-LOKf-lOaH-K5nZ-3wod-2X7m-07cogG

LV Write Access read/write

LV Creation host, time jing1, 2017-11-28 13:19:39 + 0800

LV Status available

# open 0

LV Size 15.00 GiB

Current LE 3840

Segments 1

Allocation inherit

Read ahead sectors auto

-currently set to 256

Block device 253:3

[root@jing1 /] # cat / etc/fstab

#

# / etc/fstab

# Created by anaconda on Fri Feb 10 10:35:59 2017

#

# Accessible filesystems, by reference, are maintained under'/ dev/disk'

# See man pages fstab (5), findfs (8), mount (8) and/or blkid (8) for more info

#

/ dev/mapper/vg_jing1-lv_root / ext4 defaults 1 1

UUID=3b96274e-550d-43fa-96c3-2a4b0b6684dc / boot ext4 defaults 1 2

/ dev/mapper/vg_jing1-lv_home / home ext4 defaults 1 2

/ dev/mapper/vg_jing1-lv_swap swap swap defaults 0 0

Tmpfs / dev/shm tmpfs defaults 0 0

Devpts / dev/pts devpts gid=5,mode=620 0 0

Sysfs / sys sysfs defaults 0 0

Proc / proc proc defaults 0 0

Format lvm:

[root@jing1 /] # mkfs.ext4 / dev/vg_jing1/lv_test

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

983040 inodes, 3932160 blocks

196608 blocks (5.00%) reserved for the super user

First data block=0

Maximum filesystem blocks=4026531840

120 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, 1605632, 2654208

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.

Mount lv_test to the / test directory

[root@jing1 /] # mkdir / test

[root@jing1 /] # mount / dev/vg_jing1/lv_test / test

[root@jing1 /] # df-h

Filesystem Size Used Avail Use% Mounted on

/ dev/mapper/vg_jing1-lv_root 231G 27G 193G 13% /

Tmpfs 16G 228K 16G 1% / dev/shm

/ dev/sda1 485m 39m 421m 9% / boot

/ dev/sr0 3.6G 3.6G 0100% / media/RHEL_6.5 x861464 Disc 1

/ dev/mapper/vg_jing1-lv_home 2.0G 198M 1.7G 11% / home

/ dev/mapper/vg_jing1-lv_test 15G 166m 14G 2% / test

Next, delete the lv_test logical volume and create a logical volume named lv_asm for database use:

[root@jing1 /] # umount / test

[root@jing1 /] #

[root@jing1 /] # df-h

Filesystem Size Used Avail Use% Mounted on

/ dev/mapper/vg_jing1-lv_root 231G 27G 193G 13% /

Tmpfs 16G 228K 16G 1% / dev/shm

/ dev/sda1 485m 39m 421m 9% / boot

/ dev/sr0 3.6G 3.6G 0100% / media/RHEL_6.5 x861464 Disc 1

/ dev/mapper/vg_jing1-lv_home 2.0G 198M 1.7G 11% / home

[root@jing1 /] # lvdisplay

-Logical volume

LV Path / dev/vg_jing1/lv_root

LV Name lv_root

VG Name vg_jing1

LV UUID shkBg6-9RqZ-AhDG-qfVf-d51Z-nsoS-qvF7Da

LV Write Access read/write

LV Creation host, time jing1, 2017-02-10 10:33:09 + 0800

LV Status available

# open 1

LV Size 234.38 GiB

Current LE 60000

Segments 1

Allocation inherit

Read ahead sectors auto

-currently set to 256

Block device 253:0

-Logical volume

LV Path / dev/vg_jing1/lv_swap

LV Name lv_swap

VG Name vg_jing1

LV UUID FQE8o0-yOKG-S4ip-Cvry-qSdk-v3f9-uPSa1e

LV Write Access read/write

LV Creation host, time jing1, 2017-02-10 10:33:50 + 0800

LV Status available

# open 1

LV Size 15.75 GiB

Current LE 4032

Segments 1

Allocation inherit

Read ahead sectors auto

-currently set to 256

Block device 253:1

-Logical volume

LV Path / dev/vg_jing1/lv_home

LV Name lv_home

VG Name vg_jing1

LV UUID FTLjIk-zr5B-M5ak-WdXB-c2Zs-c0eC-xZ6YBp

LV Write Access read/write

LV Creation host, time jing1, 2017-02-10 10:33:51 + 0800

LV Status available

# open 1

LV Size 2.00 GiB

Current LE 512

Segments 1

Allocation inherit

Read ahead sectors auto

-currently set to 256

Block device 253:2

-Logical volume

LV Path / dev/vg_jing1/lv_test

LV Name lv_test

VG Name vg_jing1

LV UUID l1IhX5-LOKf-lOaH-K5nZ-3wod-2X7m-07cogG

LV Write Access read/write

LV Creation host, time jing1, 2017-11-28 13:19:39 + 0800

LV Status available

# open 0

LV Size 15.00 GiB

Current LE 3840

Segments 1

Allocation inherit

Read ahead sectors auto

-currently set to 256

Block device 253:3

[root@jing1 /] # vgdisplay

-Volume group

VG Name vg_jing1

System ID

Format lvm2

Metadata Areas 1

Metadata Sequence No 6

VG Access read/write

VG Status resizable

MAX LV 0

Cur LV 4

Open LV 3

Max PV 0

Cur PV 1

Act PV 1

VG Size 299.51 GiB

PE Size 4.00 MiB

Total PE 76674

Alloc PE / Size 68384 / 267.12 GiB

Free PE / Size 8290 / 32.38 GiB

VG UUID 1IW8eG-arlp-kvje-wFLT-pC5d-AcY0-RulpNe

[root@jing1 /] # pvdisplay

-Physical volume

PV Name / dev/sda2

VG Name vg_jing1

PV Size 299.51 GiB / not usable 3.00 MiB

Allocatable yes

PE Size 4.00 MiB

Total PE 76674

Free PE 8290

Allocated PE 68384

PV UUID fusHvY-5mpq-X2bO-pbdC-2AWl-m4wO-cUf07p

[root@jing1 /] # lvremove / dev/vg_jing1/lv_test

Do you really want to remove active logical volume lv_test? [y/n]: y

Logical volume "lv_test" successfully removed

[root@jing1 /] #

[root@jing1 /] # pvdisplay

-Physical volume

PV Name / dev/sda2

VG Name vg_jing1

PV Size 299.51 GiB / not usable 3.00 MiB

Allocatable yes

PE Size 4.00 MiB

Total PE 76674

Free PE 12130

Allocated PE 64544

PV UUID fusHvY-5mpq-X2bO-pbdC-2AWl-m4wO-cUf07p

[root@jing1 /] # vgdisplay

-Volume group

VG Name vg_jing1

System ID

Format lvm2

Metadata Areas 1

Metadata Sequence No 7

VG Access read/write

VG Status resizable

MAX LV 0

Cur LV 3

Open LV 3

Max PV 0

Cur PV 1

Act PV 1

VG Size 299.51 GiB

PE Size 4.00 MiB

Total PE 76674

Alloc PE / Size 64544 / 252.12 GiB

Free PE / Size 12130 / 47.38 GiB

VG UUID 1IW8eG-arlp-kvje-wFLT-pC5d-AcY0-RulpNe

[root@jing1 /] #

[root@jing1 /] # lvcreate-L 45G-n lv_asm vg_jing1

Logical volume "lv_asm" created

[root@jing1 /] # mkfs.ext4 / dev/vg_jing1/lv_asm

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

2949120 inodes, 11796480 blocks

589824 blocks (5.00%) reserved for the super user

First data block=0

Maximum filesystem blocks=4294967296

360 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, 1605632, 2654208

4096000, 7962624, 11239424

Writing inode tables: done

Creating journal (32768 blocks): done

Writing superblocks and filesystem accounting information: done

This filesystem will be automatically checked every 30 mounts or

180 days, whichever comes first. Use tune2fs-c or-i to override.

[root@jing1 /] #

[root@jing1 /] #

[root@jing1 /] # lvdisplay

-Logical volume

LV Path / dev/vg_jing1/lv_root

LV Name lv_root

VG Name vg_jing1

LV UUID shkBg6-9RqZ-AhDG-qfVf-d51Z-nsoS-qvF7Da

LV Write Access read/write

LV Creation host, time jing1, 2017-02-10 10:33:09 + 0800

LV Status available

# open 1

LV Size 234.38 GiB

Current LE 60000

Segments 1

Allocation inherit

Read ahead sectors auto

-currently set to 256

Block device 253:0

-Logical volume

LV Path / dev/vg_jing1/lv_swap

LV Name lv_swap

VG Name vg_jing1

LV UUID FQE8o0-yOKG-S4ip-Cvry-qSdk-v3f9-uPSa1e

LV Write Access read/write

LV Creation host, time jing1, 2017-02-10 10:33:50 + 0800

LV Status available

# open 1

LV Size 15.75 GiB

Current LE 4032

Segments 1

Allocation inherit

Read ahead sectors auto

-currently set to 256

Block device 253:1

-Logical volume

LV Path / dev/vg_jing1/lv_home

LV Name lv_home

VG Name vg_jing1

LV UUID FTLjIk-zr5B-M5ak-WdXB-c2Zs-c0eC-xZ6YBp

LV Write Access read/write

LV Creation host, time jing1, 2017-02-10 10:33:51 + 0800

LV Status available

# open 1

LV Size 2.00 GiB

Current LE 512

Segments 1

Allocation inherit

Read ahead sectors auto

-currently set to 256

Block device 253:2

-Logical volume

LV Path / dev/vg_jing1/lv_asm

LV Name lv_asm

VG Name vg_jing1

LV UUID Fa3ufV-6Pjn-Sncv-KyKd-x6BD-GWoi-yFXjMv

LV Write Access read/write

LV Creation host, time jing1, 2017-11-28 14:00:39 + 0800

LV Status available

# open 0

LV Size 45.00 GiB

Current LE 11520

Segments 1

Allocation inherit

Read ahead sectors auto

-currently set to 256

Block device 253:3

The above is the editor to share with you how to reduce the space used in the / home directory and create a new LVM. If you happen to have similar doubts, please refer to the above analysis to understand. If you want to know more about it, you are welcome to follow the industry information channel.

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