Increase virtual memory in Centos to quickly increase swap partitions

Experiment environment: There are two important reasons for creating a swap partition. First, when the physical memory is insufficient to support system and application (process) operations, this swap space can be used as a temporary storage page for memory with low usage, allocate free memory to applications (processes) that are in urgent need. Second, even if your machine has enough physical memory, some programs will transfer the paging content that is rarely used during their initialization to the swap space, in this way, physical memory space is provided. Applications (processes) with a probability of memory leakage)