Introduction to Linux System Administrator (III)

Author Li Wanpeng
 
 
 
 
Team's department server has a total of 8 hard disks, each of which is 600 GB, but df-h. Check that there is only about GB. where is other seven harddisk? Use parted and lvm to solve this problem.
 
 
 
 
1. Use the parted tool:
 
 
 
 
[Root @ chinaltcdragon ~] # Parted
GNU parted2.1
Use/dev/sda
Welcome to GNU Parted! Type 'help' to view a list of commands.
(Parted) p
Model: IBM ServeRAID M5015 (scsi)
Disk/dev/sda: 599 GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
 
Number Start End Size File system Name flag
1 1049kB 211 MB 210 MB fat16 boot
2 211 MB 735 MB 524 MB ext4
3 735 MB 599 GB 598 GB lvm
 
 
We can see that/dev/sda has already been divided into good partitions, so we can draw a picture based on the gourd and divide the other seven harddisk according to the partition specification.
 
First, fdisk-l finds their names:
 
/Dev/sdb1 1 72825 584959999 + ee GPT
Disk/dev/sda: 599.0 GB, 598999040000 bytes
/Dev/sda1 1 72825 584959999 + ee GPT
Disk/dev/sdd: 599.0 GB, 598999040000 bytes
/Dev/sdd1 1 72825 584959999 + ee GPT
Disk/dev/sdc: 599.0 GB, 598999040000 bytes
/Dev/sdc1 1 72825 584959999 + ee GPT
Disk/dev/sdh: 599.0 GB, 598999040000 bytes
/Dev/sdh1 1 72825 584959999 + ee GPT
Disk/dev/sdg: 599.0 GB, 598999040000 bytes
/Dev/sdg1 1 72825 584959999 + ee GPT
Disk/dev/sde: 599.0 GB, 598999040000 bytes
/Dev/sde1 1 72825 584959999 + ee GPT
Disk/dev/sdf: 599.0 GB, 598999040000 bytes
/Dev/sdf1 1 72825 584959999 + ee GPT
 
 
Partition/dev/sdd:
 
[Root @ chinaltcdragon ~] # Parted/dev/sdd
GNU parted2.1
Use/dev/sdd
Welcome to GNU Parted! Type 'help' to view a list of commands.
 
View the harddisk information:
(Parted) p
Model: IBM ServeRAID M5015 (scsi)
Disk/dev/sdd: 599 GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
 
Number Start End Size File system Name flag
 
Run the mkpart command in parted to partition data. Enter help to view various commands of parted:
 
(Parted) mkpart
Partition name? []? 1
File System type? [Ext2]? Fat16
Start Point? 1049 k
End Point? 211 m
(Parted) mkpart
Partition name? []? 2
File System type? [Ext2]? Ext4
Start Point? 211 m
End Point? 735 m
(Parted) mkpart
Partition name? []? 3
File System type? [Ext2]? Ext4
Start Point? 735 m
End Point? 598 GB
 
Then set partition 1 as the boot partition:
 
(Parted) set 1 boot on
 
After the partition is completed, print the harddisk partition information again:
(Parted) p
Model: IBM ServeRAID M5015 (scsi)
Disk/dev/sdd: 599 GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
 
Number Start End Size File system Name flag
1 1049kB 211 MB 210 MB 1 Boot
2 211 MB 735 MB 524 MB 2
3 735 MB 598 GB 597 GB 3
If a partition is incorrectly distinguished during the partition process, you can use rm + Partition number to delete the partition. This input can be found through help.
 
 
 
 
Ii. Use LVM:
 
 
 
 
Here we will introduce several commands in lvm:
 
Vgscan, vgdisplay, lvscan, and pvscan.
 
The lvm operations are divided into several steps:
 
 
Create physical volume
Add physical volume to volume group
Add physical volume to logical volume
 
Create physical volume:
 
Lvm> pvcreate/dev/sdd3
Writing physical volume data to disk "/dev/sdd3"
Physical volume "/dev/sdd3" successfully created
 
View the name of the current volume group
 
Lvm> vgscan
Reading all physical volumes. This may take a while...
Found volume group "vg_chinaltcdragon" using metadata type lvm2
 
 
Add physical volume to volume group
 
Lvm> vgextend vg_chinaltcdragon/dev/sdd3
Volume group "vg_chinaltcdragon" successfully extended
 
Check the logical volume in this volume group.
Lvm> lvscan
ACTIVE '/dev/vg_chinaltcdragon/lv_root' [50.00 GiB] inherit
ACTIVE '/dev/vg_chinaltcdragon/lv_home' [1.55 TiB] inherit
ACTIVE '/dev/vg_chinaltcdragon/lv_swap' [37.42 GiB] inherit
 
Here, three logical volumes exist in the volume group vg_chinaltcdragon.
 
Add physical volume to logical volume
Lvm> lvextend/dev/vg_chinaltcdragon/lv_home/dev/sdd3
Extending logical volume lv_home to 2.09 TiB
Logical volume lv_home successfully resized
 
Check logical volume
Lvm> lvscan
ACTIVE '/dev/vg_chinaltcdragon/lv_root' [50.00 GiB] inherit
ACTIVE '/dev/vg_chinaltcdragon/lv_home' [2.09 TiB] inherit
ACTIVE '/dev/vg_chinaltcdragon/lv_swap' [37.42 GiB] inherit
 
 
You can see that the logical volume size of/dev/vg_chinaltcdragon/lv_home has increased.
 
However, df-h does not actually change:
 
[Root @ chinaltcdragon ~] # Df-h
File System capacity in use available % mount point
/Dev/mapper/vg_chinaltcdragon-lv_root
50G 3.9G 43G 9%/
Tmpfs 18G 188 K 18G 1%/dev/shm
/Dev/sda2 485 M 62 M 398 M 14%/boot
/Dev/sda1 200 M 256 K 200 M 1%/boot/efi
/Dev/mapper/vg_chinaltcdragon-lv_home
1.6 T 140G 1.4 T 10%/home
 
 
Here is 1.6T, because the team's foreigners have installed two harddisks with parted and lvm.
 
Last, use the resize2fs tool to adjust the volume of logical volume:
 
[Root @ chinaltcdragon ~] # Resize2fs/dev/vg_chinaltcdragon/lv_home
Resize2fs 1.41.12 (17-May-2010)
Filesystem at/dev/vg_chinaltcdragon/lv_home is mounted on/home; on-line resizing required
Old desc_blocks = 100, new_desc_blocks = 134
Ming an on-line resize of/dev/vg_chinaltcdragon/lv_home to 561076224 (4 k) blocks.
The filesystem on/dev/vg_chinaltcdragon/lv_home is now 561076224 blocks long.
 
 
Check again, it has been expanded to 2 TB, OK, Well done!
 
[Root @ chinaltcdragon ~] # Df-h
File System capacity in use available % mount point
/Dev/mapper/vg_chinaltcdragon-lv_root
50G 3.9G 43G 9%/
Tmpfs 18G 188 K 18G 1%/dev/shm
/Dev/sda2 485 M 62 M 398 M 14%/boot
/Dev/sda1 200 M 256 K 200 M 1%/boot/efi
/Dev/mapper/vg_chinaltcdragon-lv_home
2.1 T 142G 1.9 T 8%/home