The following dell R720 take as an example

How to reload the operating system  

Restart the machine by pressing F11 enter bootmanager, choice bios boot Menu


choice Front USB

choice install or update an existing system enter

choice English

choice us enter

choice Hard drive enter

Choose the first one /dev/sda1  enter

Enter the following interface

Enter the following interface , Wait half a jiff. , If there is no reaction , Press enter to try it

Then enter the following interface , Choose the first one


Basic Storage Devices enter


choice Fresh Installation enter next

input hostname enter next

Choose a city enter next


Input password : If the password is too simple , Optional use Anyway enter next

choice Use All Space enter next

Select the original disk of the server as target devices enter next, click write changes to disk



choice Basic Server, Bottom left selection Customize later,next

then reboot Restart the machine

network configuration

complete After installation restart , Default configuration network card It doesn't start Of . therefore Restart network card .

command :ifup em4(RHEL network card Name by em start ,CENTOS  with eth start )

to configure static state IP address , get into as follows address , Yes ifcfg-em4 conduct to configure by


In the execution of the command :ifup em4(RHEL network card Name by em start ,CENTOS  with eth start )

7. Turn off the firewall . implement :

service iptables stop    // Turn off the firewall chkconfig iptables offservice iptables
status   // View firewall status
Tips ip tables: Firewall is not running  Represents a firewall Represents a firewall Closed

modify hostname and hosts file .
vim /etc/hosts/ localhost tdhtest01 localhost4
localhost4.localdomain4 ::1 localhost localhost.localdomain localhost6
localhost6.localdomain6 tdhtest01 tdhtest02 tdhtest03 cdhtest01 cdhtest02 cdhtest03vim /etc/sysconfig/network NETWORKING=yes

Readjustment home Partition and root Size of partition ( The project needs to be unloaded here /home partition
And add the partition size to root Sub district )

     The system has just been installed , Default to /home Yes 1.5TiB, The root partition has only 200G. Now it's time to VolGroup-lv_home Zoom to 200G, And add the remaining space to the VolGroup-lv_root.

1. View disk usage
[root@slave2 jaydisk]# df -h Filesystem Size Used Avail Use% Mounted on
/dev/mapper/VolGroup-lv_root 50G 3.1G 44G 7% / tmpfs 16G 68K 16G 1% /dev/shm
/dev/sda2 485M 39M 421M 9% /boot /dev/sda1 200M 272K 200M 1% /boot/efi
/dev/mapper/VolGroup-lv_home 1.6T 442M 1.5T 1% /home

2. uninstall /home

use root Permission Operation :
[root@slave2 jaydisk]# umount /home
umount /home If you are prompted that you cannot uninstall , It is occupied by the process /home, Use the following command to terminate the occupied process :
[root@slave2 jaydisk]# fuser -m /home
3. resize partition
[root@slave2 jaydisk]# resize2fs -p /dev/mapper/VolGroup-lv_home 200G resize2fs
1.41.12 (17-May-2010) Please run 'e2fsck -f /dev/mapper/VolGroup-lv_home' first.
If prompted to run “e2fsck -f /dev/mapper/VolGroup-lv_home”, Then execute the relevant command :
[root@slave2 jaydisk]# e2fsck -f /dev/mapper/VolGroup-lv_home
Then execute the command again :
[root@slave2 jaydisk]# resize2fs -p /dev/mapper/VolGroup-lv_home 200G
notes :resize2fs To reset the disk size for

4. Mount /home, View disk usage
[root@slave2 jaydisk]# mount /home [root@slave2 jaydisk]# df -h
5. Set free space

use lvreduce The command is used to reduce LVM The amount of space occupied by the logical volume . Existing data on the logical volume may be deleted , So it must be confirmed before operation . Remember to input “y”:
[root@slave2 jaydisk]# lvreduce -L 200G /dev/mapper/VolGroup-lv_home
notes :lvreduce -L 200G Set the current file system to 200G, If lvreduce -l 200G Is a reduction from the current file system 200G
use lvreduce Reduce the size of the logical volume .

be careful : The reduced size cannot be less than the size of the file , Otherwise, data will be lost .

have access to vgdisplay Command to check the size of the operation . It can also be used fdisk -l Command view details .
[root@slave2 jaydisk]# vgdisplay --- Volume group --- ... PE Size 4.00 MiB
Total PE428656 Alloc PE / Size 68022 / 265.71 GiB Free PE / Size 360634 / 1.38
TiB# This line is the amount of free space , Wait a minute. It's all assigned to the root partition VG UUID a0DPCG-oIpJ-2m0S-23R6-ehrt-dBLr-LV5Szo ...
notes :vgdisplay For display LVM Metadata information for volume groups . find “Free PE / Size”, It's the amount of free space , Wait a minute. It's all assigned to the root partition .

6. Hang the idle space in the root directory
[root@slave2 ~]# lvextend -L +1380GiB /dev/mapper/VolGroup-lv_root
# Add to root partition 1380G space Extending logical volume lv_root to 1.40 TiB Logical volume
lv_root successfully resized [root@slave2 ~]# resize2fs -p
/dev/mapper/VolGroup-lv_root # The name is resizing , Longer execution time , Be patient resize2fs 1.41.12 (17
-May-2010) Filesystem at /dev/mapper/VolGroup-lv_root is mounted on /; on-line
resizing required old desc_blocks =4, new_desc_blocks = 90 Performing an on
-line resizeof /dev/mapper/VolGroup-lv_root to 374865920 (4k) blocks. The
filesystemon /dev/mapper/VolGroup-lv_root is now 374865920 blocks long.
7. Check the adjustment results
[root@slave2 jaydisk]# df -h only this and nothing more ,home
Partition and root The partition has been adjusted , The following section briefly describes the deletion home Partition operation , The method is similar to this .

This part is based on the specific needs of the project /home Operation steps of logical volume and partition deletion , According to the actual needs of this part of the operation centos6.5
After the system is installed , The system needs to be partitioned , According to the needs of the /home Place a partition between the partition where the root directory is located and the partition where the root directory is located , And will /home Free space under to the root directory , And will /home
The logical volume of the partition is deleted , The operation steps are as follows : uninstall /home And delete the logical volume home ( If /home If you need to back up, you must back it up first , ) # umount /home #
df -h// View disk condition # lvremove /dev/mapper/VolGroup-lv_home // Delete logical volume home # vgdisplay
// View volume group free space # lvextend -L +200GiB /dev/mapper/VolGroup-lv_root # Add to root partition 200G space #
resize2fs -p /dev/mapper/VolGroup-lv_root # The name is resizing , Longer execution time , Be patient
The following steps are critical , delete home After partitioning, make sure that the /etc/fstab Delete the contents of the corresponding deleted partition in ,
I didn't do this part for the first time , Finally, the system was reinstalled ( There are good solutions to share )# # /etc/fstab # Created by anaconda on Tue
Jun 19 15:06:13 2018 # # 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/VolGroup-lv_root / ext4 defaults 1 1
UUID=9962d56e-a579-4ab9-8c01-6f2fe2c6612c /boot ext4 defaults 1 2#
/dev/mapper/VolGroup-lv_home /home ext4 defaults 1 2
/dev/mapper/VolGroup-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 /dev/sdb1 /dfs/dn1 ext4 defaults 0 0
/dev/sdc1 /dfs/dn1 ext4 defaults 0 0 /dev/sdd1 /dfs/dn1 ext4 defaults 0 0
/dev/sde1 /dfs/dn1 ext4 defaults 0 0




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