On 30 August 2014 15:08, Chris Samuel <chris@csamuel.org> wrote:
I'd suggest iotop (should be packaged) and iosnoop which is a shell script that uses the Linux ftrace functionality to track what's going on, see here:
http://www.brendangregg.com/blog/2014-07-16/iosnoop-for-linux.html
Thanks for this. Both seem like good tools.
Only problem is, my computer seems fine right now. Hmmm. Another thought: really need to make sure cron isn't doing anything at the time. It doesn't show up on top, but need to double check this. Hmm. Looks like I do have anacron installed, so cron jobs do run when I turn the computer on. According to my log files, all cron jobs should have terminated when I saw the high iowait time this morning, and didn't run for long in any case. Unless something is forking and continues to run after cron reports it finished. Will need to check this again tomorrow. Oh, and latencytop and perf top might give insights too.
Apparently latencytop doesn't like the default Debian kernel: falidae# latencytop mount: none already mounted or /sys/kernel/debug/ busy mount: according to mtab, debugfs is already mounted on /sys/kernel/debug Please enable the CONFIG_LATENCYTOP configuration in your kernel. Exiting... falidae# mount -t falidae# ls -l /sys/kernel/debug total 0 drwxr-xr-x 2 root root 0 Aug 31 2014 acpi drwxr-xr-x 23 root root 0 Aug 31 2014 bdi drwxr-xr-x 2 root root 0 Aug 31 2014 dma_buf drwxr-xr-x 4 root root 0 Aug 30 16:46 dri drwxr-xr-x 2 root root 0 Aug 30 16:46 eeepc-wmi drwxr-xr-x 2 root root 0 Aug 31 2014 extfrag -r--r--r-- 1 root root 0 Aug 31 2014 gpio drwxr-xr-x 5 root root 0 Aug 30 16:46 hid drwxr-xr-x 2 root root 0 Aug 31 2014 kprobes drwxr-xr-x 2 root root 0 Aug 30 16:46 kvm drwxr-xr-x 2 root root 0 Aug 31 2014 mce drwxr-xr-x 2 root root 0 Aug 30 16:46 mei drwxr-xr-x 2 root root 0 Aug 30 16:46 pkg_temp_thermal drwxr-xr-x 2 root root 0 Aug 31 2014 pstate_snb drwxr-xr-x 2 root root 0 Aug 31 2014 regmap -rw-r--r-- 1 root root 0 Aug 31 2014 sched_features -r--r--r-- 1 root root 0 Aug 31 2014 sleep_time -r--r--r-- 1 root root 0 Aug 31 2014 suspend_stats drwxr-xr-x 6 root root 0 Aug 31 2014 tracing drwxr-xr-x 2 root root 0 Aug 30 16:46 usb -r--r--r-- 1 root root 0 Aug 31 2014 wakeup_sources drwxr-xr-x 2 root root 0 Aug 31 2014 x86 # -- Brian May <brian@microcomaustralia.com.au>