Purpose
Each physical hardware device can create multiple logical network devices, users can configure one or more logical network devices using different nicknames and different configuration options, these devices Both are associated with a physical device.
For example, a laptop user with only one Ethernet card (eth0), in the home in order to use a static IP configuration with another computer, and use DHCP client configuration in the company, then configure two A logical network device, named eth0_office and eth0_home, respectively.
device alias is usually used to represent the device name, colon, and numbers, such as eth0: 1.
device alias is used to configure multiple IP addresses to a network card.
Difference
The same point: device alias and logical network devices can be associated with the same physical hardware device.
Different points: The logical network device associated with the same physical device must exist in different configuration files and cannot be activated at the same time. The device alias associated with the same physical hardware is activated simultaneously and has different IP addresses.
Definition
Definition
logical backup device is an alias for users to physical devices. The name of the logical device is saved in the system table of the SQL Serve 2005 database. The advantage of logical devices is that the logical device name can be simply used without giving complex physical device paths. For example, using a logical backup device BK_JWGL without giving the path where a complex physical device is located. In addition, use logic devices facilitate user management backup information.
logic backup
User Before using the logical backup device, saving the logical backup device to save the database backup must exist. Otherwise, the user needs to create a logical backup device for saving the database backup. Below you in the SQL Server Management Studio tool, create a new "BK_JWGL" logical backup device. The specific procedure is as follows.
(1) Open SQL Server Management Studio and connect to the Database Engine Server.
(2) In the Object Explorer window, expand the Server Object node.
(3) Right-click the Backup Device option, select the New Backup Device command in the shortcut menu that pops up to open the Backup Device dialog. Enter bk_jwgl in the "Device Name" text box, add the path and file name of the newly-built device in the "File" text box in the "Destination" option group, "D: \ Practice_JWGL \ BK_JWGL.BAK", as shown in Figure 1.
(4) Click the "OK" button to complete the creation of the logical backup device BK_JWGL.
At this time, you can see the BK_JWGL logic backup device under the Server Objects node in the Object Explorer window. Users can right-click on the BK_JWGL option to select the corresponding menu command to complete the BK_JWGL logic backup device operation (for example, writing Transact-SQL scripts and delete). Where users can select the Properties command to open the Backup Device Properties dialog. Select the Media Content option to view the contents of the BK_JWGL logical backup device via the Backup Set box, as shown in Figure 2.
Add method
Logic device is an entity containing a device or device group. RFID (RF Identity) administrator can create a logical device to provide a business context to a group of physical devices. Examples of logical devices include: Shipment equipment (logical groups mapped to physical devices) or logical groups for physical devices (mapping to physical devices).
You can add logical devices to BizTalk RFID using the following methods:
Using the "Browse" tab of the process.
Using the Binding wizard.
Add logic device
in the console tree using the "Browse" tab, select a process in the Process Node.
At this point, the process topology is displayed in the "Browse" tab of the result pane.
Right-click this process, select Stop, and then click Edit.
Right-click Device Binding in Process Topology, and then click New Logic Device. The New Logic Device dialog is displayed.
Precautions
Click after the process is started, you cannot add a logical device to the process. A logical device can only be added to it when the process is in the "unfounded" state.
In the Logical Device Name box, type the name of the new logical device. "expression". The Regular Expression dialog is displayed.
In the Expression field, type an expression with Perl, and then click Add.
The expression you type is displayed in "existing regular expression "List.
To remove this expression from the list, click Delete.
To apply the changes, click Apply.
In the "Device and Group" list, select the device you want to include in a new logical device.
To change the name of the logical device, click New Logic Device Node and click "Rename" in the "Operation" menu.
can continue to bind logic devices to one or more physical devices.