1
00:00:06,690 --> 00:00:09,330
- So for this one, we
need to open a root cell.

2
00:00:09,330 --> 00:00:12,810
Sudo minus i is the best
way to open a root cell.

3
00:00:12,810 --> 00:00:15,900
And then dd if is dev zero,

4
00:00:15,900 --> 00:00:18,570
which in fact is reading the input file

5
00:00:18,570 --> 00:00:20,190
if is for input file

6
00:00:20,190 --> 00:00:21,810
and the input file is dev zero

7
00:00:21,810 --> 00:00:24,457
that's special device
that is generating zeros

8
00:00:24,457 --> 00:00:28,409
of is dev null that's the output file.

9
00:00:28,409 --> 00:00:31,680
And the output file is a
special device dev null.

10
00:00:31,680 --> 00:00:33,117
It's a discard device

11
00:00:33,117 --> 00:00:35,910
and, we need to run
this as a background job

12
00:00:35,910 --> 00:00:37,226
and three times.

13
00:00:37,226 --> 00:00:39,000
So there we go.

14
00:00:39,000 --> 00:00:41,280
Then we need to use the
appropriate command to show

15
00:00:41,280 --> 00:00:43,410
that they are running as expected.

16
00:00:43,410 --> 00:00:44,610
Well, that's something that you can do

17
00:00:44,610 --> 00:00:48,389
with PS aux pipe, grab DD, for instance.

18
00:00:48,389 --> 00:00:50,202
And there, we can see

19
00:00:50,202 --> 00:00:55,130
that the three DD processes
are running as expected.

20
00:00:55,130 --> 00:00:57,060
Now, if you want to have information

21
00:00:57,060 --> 00:01:00,720
about a performance as
well, I would say go for top

22
00:01:00,720 --> 00:01:02,714
because top is giving
you this nice interface

23
00:01:02,714 --> 00:01:05,018
in which you can see all the properties

24
00:01:05,018 --> 00:01:09,270
of the process being updated in real time.

25
00:01:09,270 --> 00:01:10,980
if stuff is changing.

26
00:01:10,980 --> 00:01:12,360
Now the next thing we needed to do,

27
00:01:12,360 --> 00:01:15,030
is change the process priority so that one

28
00:01:15,030 --> 00:01:20,030
of these three jobs gets double
the amount of CPU resources.

29
00:01:20,430 --> 00:01:24,330
So that will be our, from
the top interface to re nice

30
00:01:24,330 --> 00:01:28,111
I'm picking 6, 6 20, and I
wanted to have a higher priority.

31
00:01:28,111 --> 00:01:31,260
Well, let's give it the priority

32
00:01:31,260 --> 00:01:35,280
of minus 10 and then let's observe.

33
00:01:35,280 --> 00:01:38,100
And here we can see after one polling loop

34
00:01:38,100 --> 00:01:41,670
that this process 6, 6, 6
2 0 is 66, 20 is staying

35
00:01:41,670 --> 00:01:44,970
on processor number zero, and it's getting

36
00:01:44,970 --> 00:01:48,573
about a hundred percent of CPU cycles.

37
00:01:50,562 --> 00:01:51,395
And that is all.

38
00:01:51,395 --> 00:01:53,640
Now we need to terminate
all three processes.

39
00:01:53,640 --> 00:01:58,100
The easiest way to do so is
by using kill all, kill all DD

40
00:02:00,325 --> 00:02:01,158
will terminate all of them.

41
00:02:01,158 --> 00:02:03,400
And you can see kill is telling that four

42
00:02:05,032 --> 00:02:06,330
the three processes and
they are now all gone.

43
00:02:06,330 --> 00:02:08,630
And that is what you
needed to do in this lab.