In a Ubuntu 14.04 server I am experiencing a massive hard disk activity which has no apparent justification: it comes as a burst, it lasts a few minutes and then disappears. It consumes system resources and slows down the whole system.
Is there a (command-line) tool which can be used to monitor the disk activity, listing the processes that are using the disk and the files involved? Something like htop for the CPU.
For checking I/O usage I usually use iotop. It's not installed by default on the distro, but you can easily get it with:
sudo apt-get install iotop Then launch it with root priviledges:
sudo iotop --only The --only option will show only the processes currently accessing the I/O.
--only option is really interesting because it will only show processes or threads actually doing I/O. iotop shows no processes except for periodic blips of a few KB/s iotop has to be launched with sudo, so it should see all processes accessing the HDD from all users. You can try nmon
sudo apt-get install nmon Try:
nmon Output Like below:
Press d = Disk Press c = CPU Press r = RAM Press q to exit
You can also give try with:
iostat Output like below:
Linux 3.16.0-30-generic (client01) 03/01/2016 _i686_ (2 CPU) avg-cpu: %user %nice %system %iowait %steal %idle 39.73 24.58 2.96 0.26 0.00 32.48 Device: tps kB_read/s kB_wrtn/s kB_read kB_wrtn sda 3.32 57.31 40.05 119879872 83767716 sdb 1.45 15.02 22.60 31424408 47273012 Something like htop for the CPU.
atop - AT Computing's System & Process Monitor
# apt-get install -y atop # atop It has a similar interface to htop.
Now press shift+d - for disk activity
Then press c - for full command name..
PID DSK COMMAND-LINE 28497 37% /usr/sbin/apache2 -k start 28496 36% /usr/sbin/apache2 -k start 30528 11% mplayer .......... ..... collectl tool can also play the role of utilities that are designed with only a specific purpose such as top, ps, iotop and many others.
install:
sudo apt-get install collectl For example the following command collectl -sc can be used to monitor the summary of the cpu usage.
The following command collectl -sd will help you to monitor the disk usage.
You can also use collectl -sD to collect data on individual disks, but you have to know that information on total disks will not be reported.
It is very easy to make collectl work as the top utility, just run the following command in your terminal collectl --top and you will see the similar output the top tool gives you when it is executed in your Linux system.
to use the collectl utility as the ps tool run the following command in your terminal:
collectl -c1 -sZ -i:1
You will get information about processes in your system the same way as you do when you run the ps command in your terminal.
you can combine the t for tcp and c for cpu example collectl -stc
the summary list of subsystems supported by the tool:
b – buddy info (memory fragmentation) c – CPU d – Disk f – NFS V3 Data i – Inode and File System j – Interrupts l – Lustre m – Memory n – Networks s – Sockets t – TCP x – Interconnect y – Slabs (system object caches) collectl visualised through graphite or graphiti:
gvfsd-metadataand the other one has a similar name (anyway, I'm not sure about the names: try googling to get more details about them). They continuously explore the filesystem to collect information about files: if they are not necessary for your systems, there is a way to disable their execution.