iotopper.py

#!/usr/bin/env python

'''
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Copyright (C) 2016  Andrés M. R. Martano

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.

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Iotop displays accumulated writes to disks by process, but I couldn't
configure it to solve two problems:
- It stops displaying process that terminated.
- It doesn't show to which HD writes are going to.
So I made this small dirty script to try to solve this points.
It displays process even after they terminated, and keeps accumulating
values if they are restarted.
It can't tell to which partition they wrote to, but it also displays
total writes to a set partition (see bellow) so you can try to guess
what's going on (at least if you only have 2 relevant partitions like
me =P).

Run this script like this:
iotop -boqqq | <path to this script>
(iotop requires root)
Values are in MBs.

The "Writes Iotop" are the total writes accumulated from Iotop data.
The "Writes SysFs" are the total changes to the set partition
"lifetime_write_kbytes" file since the script started running.

**YOU NEED TO EDIT THE "PATH_TO_HD_FILE" VAR BELLOW.**

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'''

import sys

sizes = {
    'B': 1,
    'K': 1e3,
    'M': 1e6,
    'G': 1e9,
}

uses = {}


# Change the line bellow to the correct path to the partition
# you want to monitor:
PATH_TO_HD_FILE = '/sys/fs/ext4/<partition>/lifetime_write_kbytes'


def get_hd_total_write():
    arq = open(PATH_TO_HD_FILE, 'r')
    total = arq.read()
    arq.close()
    return int(total.strip())


init_writes = get_hd_total_write()


def print_all():
    in_order = sorted(uses.items(), key=lambda x: x[1]['write'], reverse=False)
    total_w = 0
    total_r = 0
    for name, entry in in_order:
        total_w += entry['write']
        total_r += entry['read']
        print(name)
        w = str(entry['write']/1e6).rjust(15)
        r = str(entry['read']/1e6).rjust(15)
        print(w, r)
    os_write_diff = get_hd_total_write() - init_writes
    print('----------------')
    print('Writes Iotop:     ', total_w/1e6)
    print('Writes SysFs:     ', os_write_diff/1e3)
    print('Diff Iotop/Sysfs: ', round((os_write_diff-total_w/1e3)/1e3, 3))
    print('Reads:            ', total_r/1e6)
    print('----------------')


for line in sys.stdin:
    try:
        a, _, b = line.partition('%')
        b, _, name = b.partition('%')
        a = a + b
        id_, prio, user, read, read_size, write, write_size, swapin, io_, = a.split()
        name = name.strip()
    except:
        print(line)
        print(a)
        print(name)
        raise
    read = float(read) * sizes[read_size[0]]
    write = float(write) * sizes[write_size[0]]
    entry = uses.get(name)
    if not entry:
        entry = {
            'write': 0,
            'read': 0,
        }
        uses[name] = entry
    entry['write'] += write
    entry['read'] += read
    print_all()