(Swap被频繁使用时,说明物理内存不足。解决方法: 1.top查看哪些进程消耗较多内存,kill掉它们;2.reboot server能有效地释放swap) 为了提高磁盘存取效率, Linux做了一些精心的设计, 除了对dentry进行缓存(用于VFS,加速文件路径名到inode的转换), 还采取了两种主要Cache方式:Buffer Cache和Page Cache。前者针对磁盘块的...
vmstat is used to display virtual memory statistics. The vmstat command displays the information about processes, memory, paging, block IO, traps, disks and cpu activity. The vmstat command option -s or –stats is used to display a table of various event counters and memory statistics. See th...
%cpuCPU utilization of the process in “##.#” format. Currently, it is the CPU time used divided by the time the process has been running (cputime/realtime ratio), expressed as a percentage. %memRatio of the process’s resident set size to the physical memory on the machine, expresse...
Assume that the program will create a memory portion, which another process can access (if permitted). A shared segment can be attached multiple times by the same process. Whenever the memory is mapped into the address space of the process, i.e. sharing the common memory region, the kernel...
Know Your Linux System Information Summary The "uname" command is a useful tool for obtaining basic information about the operating system and hardware platform of a Linux computer. You can use different options with the "uname" command to retrieve specific information like the system hostname, ke...
If you’re not familiar with the sudo command, see the Linux Users and Groups guide. Reading the Results of the ping Command Before starting in on how to use ping, it can be helpful to know how ping displays results. To get your footing with that, look into an example ping command ...
Next, we copied the string Hello World!!! using the strcpy() function. Finally, we blocked the program’s execution with the getchar() function, so that we have time to examine its memory. Another key point is that the character array is allocated in the process’s heap space due to ...
(KiB) nDRT = Dirty Pages Count * SHR = Shared Memory (KiB) WCHAN = Sleeping in Function * S = Process Status Flags = Task Flags * %CPU = CPU Usage CGROUPS = Control Groups * %MEM = Memory Usage (RES) SUPGIDS = Supp Groups IDs * TIME+ = CPU Time, hundredths SUPGRPS = Supp ...
As we all knowLinux/Unixconsiderseverything as a file(pipes,sockets,directories,devices,etc). One of the reasons to use thelsofcommand is when a disk cannot be unmounted as it says the files are being used. With the help oflsofcommand, we can easily identify the files which are in use...
15.1. Estimating the kdump size When planning and building yourkdumpenvironment, it is important to know the space required by the crash dump file. Themakedumpfile --mem-usagecommand estimates the space required by th...