iostat and vmstat – Awesome System Statistics for Linux | Two excellent Linux apps are iostat and vmstat. These provide realtime statistics of system IO and memory usage. Here’s how it works! iostat iostat is useful to view realtime stats of disk IO. I suggest running ‘iostat 1′ to have the command refresh each second. $ iostat 1 Linux 3.2.0-2-amd64 (brahms) 09/12/2012 _x86_64_ (4 CPU)
OS X Monitor Virtual Memory Usage from Command Line | OS X has a simple command line tool to monitor virtual memory usage: vm_stat. I’ll show you how it works! Crack open a terminal and run vm_stat. You will see an output somewhat like below: $ vm_stat Mach Virtual Memory Statistics: (page size of 4096 bytes) Pages free: 54492. Pages active: 541989. Pages inactive: 155818.
Apache List Loaded Modules | Use apache2ctl -M or httpd -M to list loaded apache modules. The output will look similar to: $ sudo apache2ctl -M Loaded Modules: core_module (static) log_config_module (static) logio_module (static) mpm_worker_module (static) http_module (static) so_module (static) alias_module (shared) auth_basic_module (shared) authn_file_module (shared) authz_default_module (shared) authz_groupfile_module (shared) authz_host_module (shared) authz_user_module (shared) autoindex_module (shared) cgid_module (shared) deflate_module (shared)