37
votes
What does Virtual memory size in top mean?
I found this explanation from Mugurel Sumanariu very clear:
VIRT stands for the virtual size of a process, which is the sum of
memory it is actually using, memory it has mapped into itself (for
...
17
votes
Show full process name in top
top -c -n 1 should give you what you want.
-c: automatically toggles between command line and program name
-n 1: this makes top to exit out immediately without showing the updates every 3 seconds (by ...
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16
votes
Which Linux package contains the 'top' command?
You can do yum whatprovides <path> to see what package provides a file. For example, yum whatprovides /usr/bin/top will tell you for top or yum whatprovides '*/top' if you weren't sure of the ...
- 939
15
votes
Accepted
Which Linux package contains the 'top' command?
The "top" utility is in the "procps" package on RHEL/CentOS systems.
- 196k
13
votes
10 GB of RAM unaccounted for by top
Your smem -tw output shows that your kernel is consuming over 9 GB of dynamic memory:
danslimmon@bad-server:~$ smem -tw
Area Used Cache Noncache
firmware/hardware ...
- 45.5k
10
votes
what percentage of iowait is considered to be high?
The best answer I can give you is "iowait is too high when it's affecting performance."
Your "50% of the CPU's time is spent in iowait" situation may be fine if you have lots of I/O and very little ...
- 79.6k
9
votes
top is only showing current user processes
One possibility is /proc mounted with either hidepid=1 or hidepid=2. This mount option was added in latter Linux kernels and back ported sometime around CentOS 5.9 and 6.3.
Mount options
The ...
- 3,436
9
votes
Accepted
High CPU usage without useful information from top command
About 30% of CPU time seems to be spent in WAIT, and your (1 minute, at least) load is very high.
So I would start by checking your storage, and storage usage patterns.
A good starting point might be ...
- 3,618
8
votes
How to have linux top command show memory summary in megabytes not kilobytes
Typing capital 'E' cycles through KiB, MiB, GiB, TiB, PiB and EiB.
7
votes
What exactly do the colors in htop status bars mean?
There are several different colors for each of the bars, except the Swap bar. Here are the color keys used inside of htop:
- 308
6
votes
Accepted
How do I list processes in htop by just their name, without the full path?
As an update, now apparently there is an option in Setup/DisplayItems Show Program Path that is checked by default. Just need to uncheck that so only the command name is shown.
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6
votes
CentOS 7.1 - Reverting to Old Functionality of top and service
CentOS 7 is a significantly different OS from CentOS 6. Instead of wanting to go backwards you should embrace the change and move forwards. You can't go backwards with these commands (or any others ...
- 115k
6
votes
Accepted
CentOS 7.1 - Reverting to Old Functionality of top and service
Question 1
Try using top -M instead.
-M : Detect memory units
Show memory units (k/M/G) and display floating point values in the
memory summary.
KiB is a SI unit representing 1000 ...
- 1,137
6
votes
High CPU usage without useful information from top command
You have not described what the problem is. If there was a performance problem, such as applications not being responsive enough, describe it.
The load average is not the number of cores in use. It ...
- 31.1k
5
votes
Find out what high CPU usage apache process is actually doing?
An very easy approach is to use htop. You can sort for the high CPU processes and then use
s for strace a process
l for lsof to see the open files of a processes
L to ltrace.
I found that at least ...
- 156
5
votes
Why is this server reporting high memory usage
Because that's how modern operating systems work. You can't save RAM for later. A 4GB machine that uses only 2GB today can't use 6GB tomorrow -- it just wasted 2GB today. So your only choices are to ...
- 31.4k
5
votes
Accepted
Why is this server reporting high memory usage
31047712 cached Mem
looks like you have a lot of stuff cached. Please refer to the venerable linuxatemyram.com
- 115k
4
votes
What does %st mean in top?
Steal Time or stolen time, mean the amount of time that your host in VM is ready to run (some instruction), but could not do this because other's VM competing for the CPU. When the value get bigger, ...
- 41
4
votes
What does Virtual memory size in top mean?
VIRtual column of the top, refers to the super-space (super consumption space) of the process, which the process might not be actually taking at the run time. There is another column RESident, which ...
- 141
4
votes
How to exclude some users from Linux Top screen?
Also, as of version 3.3, you can just type u while top is running and enter that !root string.
- 41
4
votes
CentOS 7.1 - Reverting to Old Functionality of top and service
Your second question about the lack of status when restarting the httpd service is perfectly reasonable.
The service command being deprecated you will need to get used to the systemctl command. But ...
- 41
4
votes
Accepted
What do angle brackets ("less than") mean in busybox 'top' command process STAT column?
The angle bracket means "high-priority". See "man ps" for more details:
PROCESS STATE CODES
D uninterruptible sleep (usually IO)
R runnable (on run queue)
S sleeping
T traced ...
4
votes
High CPU usage without useful information from top command
You should install atop. It is more informative.
Your CPU is used by input/output operations. WA - is waiting and it is more 30%. I see that more useful process is mysqld. It eat CPU time more than ...
- 2,053
4
votes
Why are cpu usage percentage different between top and iostat?
The reason for this is that on a single run of iostat the statistics reported are since system boot. iostat -c 2 2 will report once since boot, then 2 seconds later with a second report since the ...
- 181
3
votes
How to interpret output from Linux 'top' command?
Top isn't the best way to check memory usage. However, since my question was marked as a duplicate of this question, I'm going to post my resolution here.
I read on a forum that ps_mem.py will check ...
- 1,385
3
votes
Linux - How can I see what's waiting for disk IO
Enable block_dump logging of what processes are doing block read/write operations:
echo 1 > /proc/sys/vm/block_dump
tail -f /var/log/syslog
when done, disable the tracing so you don't spam your ...
- 2,445
3
votes
How do I list processes in htop by just their name, without the full path?
To make htop display only nginx processes:
htop -p $(pgrep nginx | paste -s -d,)
- 31
3
votes
Accepted
top is only showing current user processes
Based on the information from the following posts I have identified 3 possible resolutions.
htop shows only the processes of the user that's running it? on Unix & Linux
https://www.centos.org/...
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3
votes
Accepted
Understanding top and tuning
VIRT colums does not really show the total allocated memory. Rather, it only show how much memory was mapped in the process user space. In other words, its has nothing to do with swapping.
As a ...
- 45.5k
3
votes
Accepted
How to understand the "SIZE" output of the command top on FreeBSD
What you are looking for is the RES column, which is the actual memory (RAM) used by the process. SIZE also includes files that are maped by the process (so if those are large SIZE goes up, but the ...
- 103
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