Backend DevelopmentPHP TutorialLVM type Storage Pool - Play with OpenStack in 5 minutes a day (8)_PHP tutorialLVM type Storage Pool - Play with OpenStack in 5 minutes a day (8)_PHP tutorial
LVM type Storage Pool - Play with OpenStack in 5 minutes a day (8)
LVM type Storage Pool
Not only can a file be assigned to the guest machine as a virtual disk, but the LV in the VG on the host machine can also be assigned to the virtual machine as a virtual disk.
However, since LV does not have the MBR boot record of the disk, it cannot be used as a startup disk for a virtual machine and can only be used as a data disk.
In this configuration, the VG on the host is a Storage Pool, and the LV in the VG is the Volume.
The advantage of LV is that it has better performance; its disadvantage is that it is not as good as image files in terms of management and mobility, and it cannot be used remotely through the network.
Here’s an example.
First, create a VG with a capacity of 10G on the host machine and name it HostVG.
Then a Storage Pool definition file /etc/libvirt/storage/HostVG.xml was created with the content of
Then create a new Storage Pool “HostVG” via virsh command
and enable this HostVG
Now we You can add the LV virtual disk to the virtual machine kvm1 in virt-manager.
Click Browse
You can see that HostVG is already in the list of Stroage Pool, select HostVG
Name the volume newlv and set the size to 100MB
Click Finish, newlv is created successfully
Click Choose Volume
Click Finish to confirm adding newlv as volume to kvm1
The new volume is added successfully
On the host machine then There is an additional LV named newlv
Other types of Storage Pool
KVM also supports iSCSI, Ceph and other types of Storage Pool, here is I won’t introduce them one by one. The most commonly used type is the directory type. For other types, please refer to the document http://libvirt.org/storage.html
In the next section we will start to discuss the network virtualization principles of KVM
How do you modify data stored in a PHP session?Apr 27, 2025 am 12:23 AMTomodifydatainaPHPsession,startthesessionwithsession_start(),thenuse$_SESSIONtoset,modify,orremovevariables.1)Startthesession.2)Setormodifysessionvariablesusing$_SESSION.3)Removevariableswithunset().4)Clearallvariableswithsession_unset().5)Destroythe
Give an example of storing an array in a PHP session.Apr 27, 2025 am 12:20 AMArrays can be stored in PHP sessions. 1. Start the session and use session_start(). 2. Create an array and store it in $_SESSION. 3. Retrieve the array through $_SESSION. 4. Optimize session data to improve performance.
How does garbage collection work for PHP sessions?Apr 27, 2025 am 12:19 AMPHP session garbage collection is triggered through a probability mechanism to clean up expired session data. 1) Set the trigger probability and session life cycle in the configuration file; 2) You can use cron tasks to optimize high-load applications; 3) You need to balance the garbage collection frequency and performance to avoid data loss.
How can you trace session activity in PHP?Apr 27, 2025 am 12:10 AMTracking user session activities in PHP is implemented through session management. 1) Use session_start() to start the session. 2) Store and access data through the $_SESSION array. 3) Call session_destroy() to end the session. Session tracking is used for user behavior analysis, security monitoring, and performance optimization.
How can you use a database to store PHP session data?Apr 27, 2025 am 12:02 AMUsing databases to store PHP session data can improve performance and scalability. 1) Configure MySQL to store session data: Set up the session processor in php.ini or PHP code. 2) Implement custom session processor: define open, close, read, write and other functions to interact with the database. 3) Optimization and best practices: Use indexing, caching, data compression and distributed storage to improve performance.
Explain the concept of a PHP session in simple terms.Apr 26, 2025 am 12:09 AMPHPsessionstrackuserdataacrossmultiplepagerequestsusingauniqueIDstoredinacookie.Here'showtomanagethemeffectively:1)Startasessionwithsession_start()andstoredatain$_SESSION.2)RegeneratethesessionIDafterloginwithsession_regenerate_id(true)topreventsessi
How do you loop through all the values stored in a PHP session?Apr 26, 2025 am 12:06 AMIn PHP, iterating through session data can be achieved through the following steps: 1. Start the session using session_start(). 2. Iterate through foreach loop through all key-value pairs in the $_SESSION array. 3. When processing complex data structures, use is_array() or is_object() functions and use print_r() to output detailed information. 4. When optimizing traversal, paging can be used to avoid processing large amounts of data at one time. This will help you manage and use PHP session data more efficiently in your actual project.
Explain how to use sessions for user authentication.Apr 26, 2025 am 12:04 AMThe session realizes user authentication through the server-side state management mechanism. 1) Session creation and generation of unique IDs, 2) IDs are passed through cookies, 3) Server stores and accesses session data through IDs, 4) User authentication and status management are realized, improving application security and user experience.
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Safe Exam Browser
Safe Exam Browser is a secure browser environment for taking online exams securely. This software turns any computer into a secure workstation. It controls access to any utility and prevents students from using unauthorized resources.
Dreamweaver Mac version
Visual web development tools
WebStorm Mac version
Useful JavaScript development tools
EditPlus Chinese cracked version
Small size, syntax highlighting, does not support code prompt function
mPDF
mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),
