• Linux operation and maintenance — 1. Disk related knowledge


    Physical structure of disk (1) Disk: the disk body of a hard disk consists of multiple disks stacked together. When the hard disk is delivered from the factory, the hard disk manufacturer completes the low-level format (physical format), which is used to divide the blank platter into tracks with the same center and different radius, […]

  • Hyper-V installation of Ubuntu 18.04 server on win10


    To install Ubuntu 18.04 for Hyper-V on win10:1. Open Hyper-V manager and select host (ms-mhxaknzklyab), as shown below: 2. Right click the menu item of the host name, select the “quick create” button, or select the “quick create” button in the right operation bar to open the create virtual machine interface, as shown in the […]

  • Linux operation and maintenance – disk storage – 2. Raid


    With the limitations of single disk in data security, performance and capacity, raid has emerged. Raid combines multiple independent disks in different ways to form a disk group to obtain higher data security, performance and capacity than single disk. 1、 Common RAID levels Raid has several levels of raid0 ~ raid7. In addition, there are […]

  • Tricks: Clear USB Read-only Status Under Windows


    Clear USB read-only status under Windows Run Diskpart Run CMD with administrator privilege Run DISKPART to check USB disk status Diskpart Choose Disk Then under the Diskpart console, input the following instruction: DISKPAERT> list disk The result looks like: Disk status size available dyn GPT ——– ————- ——- ——- — — Disk 0 online 238 […]

  • PHP file upload and download (enclosed function file)


    Single file uploadFront page Upload A File Backend implementation of upload.php UPLOAD_ERR_OK) { switch($error) { //1 – the file size exceeds the size of upload ﹣ Max ﹣ filesize in php.ini case UPLOAD_ERR_INI_SIZE: Exit (‘the file size exceeds the size of upload [Max] file size in php.ini ‘); //2 – exceeds the size of max […]

  • Linux operation and maintenance – disk storage — 3.lvm


    How LVM works LVM (logical volume manager) logical volume management is a logical layer added between disk partition and file system to shield the layout of lower disk partition for file system, provide an abstract volume and establish file system on the volume. The administrator can use LVM to dynamically adjust the size of the […]

  • Redo log and binlog of MySQL log system


    Before that, we learned about the execution process of a query statement and introduced the processing modules involved in the execution process. The execution process of a query statement generally passes through the connector, analyzer, optimizer, executor and other functional modules, and finally reaches the storage engine. So, what is the execution flow of an […]

  • Linux Storage Stack Diagram


    There is nothing better than charts in work and study (although many people laugh at ppt), especially the accurate charts. When you want to draw a picture of a structure or a process, you must fully understand it. When explaining a picture, we must also have a basic understanding of it. It’s not easy. It’s […]

  • Linux and windows disk file types


    Linux and windows disk file types Windows file type classification There are three main types: FAT Fat, file allocation table is used by the operating system to track the location, size and other information of various files stored on the disk. Doc (disk operation system) is a typical representative of fat file system. Fat file […]

  • The use of LVM in Linux disk management


    1、 LVM introduction When we manage Linux disks, we usually encounter such a situation. In the initial planning of Linux disk, we divided a certain amount of disk space for a partition. After using it for a period of time, we found that the planned disk space was insufficient. What should we do at this […]

  • MySQL architecture summary


    Architecture *Connector: used to support the interaction between various languages and SQL, such as PHP, python, Java JDBC; *Management services & Utilities: system management and control tools, including backup and recovery, MySQL replication, clustering, etc; *Connection pool: connection pool, which manages the resources to be buffered, including user password permission thread, etc; *SQL interface: used […]

  • Linux file system related commands (DF / Du / fsck / dumpe2fs)


    1、 File system view command DF format DF [options] [mount point] option Name Effect -a Display all file system information, including special file systems, such as / proc, / sysfs -h Display capacity in customary units, such as KB, MB or GB -T Show file system types -m Display capacity in MB -k Display capacity […]