script examples summarizing disk I/O traffic examples of SystemTap scripts summarizing disk I/O traffic summarizing disk I/O traffic script examples NO ENTRY IN WAR STORIES: Summarize Disk Read/Write Traffic http://sourceware.org/systemtap/examples/io/disktop.stp disk I/O traffic, summarizing script examples I/O traffic, summarizing script examples heaviest disk reads/writes, identifying script examples summarizing disk I/O traffic script examples identifying heaviest disk reads/writes script examples This section describes how to identify which processes are performing the heaviest disk reads/writes to the system. outputs the top ten processes responsible for the heaviest reads/writes to disk. displays a sample output for this script, and includes the following data per listed process: UID — user ID. A user ID of 0 refers to the root user. PID — the ID of the listed process. PPID — the process ID of the listed process's parent process. CMD — the name of the listed process. DEVICE — which storage device the listed process is reading from or writing to. T — the type of action performed by the listed process; W refers to write, while R refers to read. BYTES — the amount of data read to or written from disk. script examples ctime(), example of usage examples of SystemTap scripts ctime(), example of usage ctime(), example of usage script examples The time and date in the output of is returned by the functions ctime() and gettimeofday_s(). ctime() derives calendar time in terms of seconds passed since the Unix epoch (January 1, 1970). gettimeofday_s() counts the actual number of seconds since Unix epoch, which gives a fairly accurate human-readable timestamp for the output. local variables sample usage $return variables (local) sample usage $return $return sample usage local variables In this script, the $return is a local variable that stores the actual number of bytes each process reads or writes from the virtual file system. $return can only be used in return probes (e.g. vfs.read.return and vfs.read.return). [...] Mon Sep 29 03:38:28 2008 , Average: 19Kb/sec, Read: 7Kb, Write: 89Kb UID PID PPID CMD DEVICE T BYTES 0 26319 26294 firefox sda5 W 90229 0 2758 2757 pam_timestamp_c sda5 R 8064 0 2885 1 cupsd sda5 W 1678 Mon Sep 29 03:38:38 2008 , Average: 1Kb/sec, Read: 7Kb, Write: 1Kb UID PID PPID CMD DEVICE T BYTES 0 2758 2757 pam_timestamp_c sda5 R 8064 0 2885 1 cupsd sda5 W 1678