One VMware clone, snapshot explanation and corresponding problem explanation:
Snapshot:
Analogy: Suppose you take a snapshot of your life.
1 year old
10 years old
20 years old 6
infinitely restored to the previous set node.
·Clone
learning generally uses linked clones, which do not occupy additional disks, but rely on the virtual machine on the body.
A full clone has nothing to do with the ontology virtual machine.
The problem of network settings after the VMWARE virtual machine is cloned under CentOS 7
CentOS7 is easier to deal with this problem, just delete the two lines of HWADDR and UUID in the configuration file for the network card and restart.
II Linux directory structure:
1. Logically, all directories (subdirectories under the package directory) are under the highest-level directory "/", and the root "/" directory is the starting point (vertex) of all directories in the Linux system. . The directory below the root and the subdirectories of the directory are a hierarchical tree structure, much like an upside-down tree, which is different from the directory structure divided by the hard disk partitions C, D, and E of the Windows system. Win can be understood as multiple A tree, each partition is an independent small tree.
These different directories in the Linux system are also very special. Different directories can be distributed on different hard disk partitions and different hard disk devices. This is difficult for the Windows system to do. Different partitions of the Windows system exist independently.
Features of Linux directory:
1. The "/" root is the vertex of all directories.
2. The directory structure is like an upside-down tree.
3. Directories and disk partitions are not associated.
4. Different directories under / may correspond to different partitions or disks.
5. All directories are regularly organized and named according to certain categories.
In Linux, if the device is not mounted, the entrance cannot be seen, which is similar to a prison with no windows and no doors.
If you want a device to be accessed, you must give the device an entry.
This entry is called a mount point, and the performance of a mount point is essentially a directory.
Example:
CD-ROM is also a device: /dev/cdrom
mount /dev/cdrom /mnt (mount /dev/cdrom to the /mnt directory through the mount command).
Historical allusions to the directory structure of the Unix system:
At that time, the hard disk was large in size and small in capacity. They added a second hard disk RK50 and made a stipulation:
the first disk is dedicated to storing system programs.
The second disk is dedicated to storing the user's own programs.
Therefore, the mounted directory point is named: /user
, that is to say, the root directory / is mounted on the first disk
/ user is mounted on the second disk
. In addition, the other directory structures in the two quick disks are: Exactly the same.
A third disk RK05 is added later, and the mounted directory is named /home, and it is specified that
/user is used to store user programs.
/home is used to store user data.
Henceforth this directory structure naming and definition is carried over. With the development of the device, the capacity of the hard disk is also getting larger and larger, and the meaning of the brother directory has been further clarified:
/ Store system-related programs, that is, Unix programs developed by At&t.
/user holds programs developed by Unix system vendors such as IBM and HP.
/user/local stores the programs installed by the user, which is equivalent to c:/programfiles. Generally, the default path when compiling software, the default path for yum or rpm package installation is generally not here.
/opt In some systems, it is used to store programs developed by third-party manufacturers, all named option, meaning: optional.
/home holds the user's data.
Linux directory knowledge points:
/bin #The directory where common binary commands are located. For example, commands such as ls cp mkdir rm cut, the /bin directory is similar to /user/bin.
Essential user command binaaries(for use by all users).
[root@localhost /]# which cat (which command: find the directory where a command is located)
/usr/bin/cat
/boot #Linux kernel and system boot programs are required file directory. When installing the system partition, it is generally necessary to divide a boot partition.
Static files of the boot loader
/dev #Device files Directory of device files, such as sound card, disk, CD-ROM...
/etc #Host-specific system configuration.
(1) The default path of the configuration file of the binary installation package (yum, rpm).
(2) The directory /etc/init.d/(yum, rpm) where the service startup command is stored. (service sshd start)
/home #The default data storage directory of the home directory of ordinary users.
/lib #Library file storage directory.