Sometimes it is not comfortable to see meminfo in kilobytes when you have several gigs of RAM. In Linux, it looks like:
And here is how it looks in Mac OS X:
Is there a way to display meminfo in Linux top in terabytes, gigabytes and megabytes?
asked Dec 19 '13 at 15:44
When in top, typing capital "E" cycles through different memory units (KiB, MiB, GiB, etc., which are different from kB, MB and GB) in the total memory info:
While lower-case "e" does the same individual process lines:
From the manpage:
2c. MEMORY Usage
This portion consists of two lines which may express values in kibibytes
(KiB) through exbibytes (EiB) depending on the scaling factor enforced
with the 'E' interactive command.
Version Information: top -version: procps-ng version 3.3.9
System: CentOS 7
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6<time machine from the future>I find the default units of Petabytes is woefully inadequate and unhelpful. I always end up having to hit E at least once to set top in units of Exabytes.</time machine from the future> – Trevor Boyd Smith Feb 16 '17 at 15:12
There is a command-line option which does that:
-M : Detect memory units
Show memory units (k/M/G) and display floating point values in the
memory summary.
So it is sufficient to run top like that:
top -M
If -M does not work you can press E while already in top.
From man top (procps-ng version 3.3.9):
E :Extend-Memory-Scale in Summary Area With this command you can cycle through the available summary area memory scaling which ranges from KiB (kibibytes or 1,024 bytes) through EiB (exbibytes or 1,152,921,504,606,846,976 bytes).
If you see a '+' between a displayed number and the following label, it means that top was forced to truncate some portion of that number. By raising the scaling factor, such truncation can be avoided.
answered Dec 19 '13 at 15:55
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28+1 , but checked in Ubuntu , its saying not working. Any way in Ubuntu ? – rɑːdʒɑ Dec 19 '13 at 15:59
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2Damn, you racked up a ton of karma with a simple (but good) self-answered Q&A. Nice work. – user1717828 Oct 29 '15 at 15:39
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You can also use htop. It's much cooler than top.
If you are using Debian or one of its derivatives, then you can install it using sudo apt-get install htop.
Edit: Here is a screenshot with a better color scheme:
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htoplooks better with either a white or a black background. Your screenshot color scheme is less than optimal. – jlliagre Dec 19 '13 at 17:42 -
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1fyi, htop comes with other color shemes which you can access by going to setup
F2. – Miguel Mota Nov 28 '16 at 20:09 -
I run with
alias top='htop --no-color'so I can type 'top' and get a reasonable replacement for top without the horrible color scheme. – SurpriseDog Jul 12 '19 at 18:18
top -M doesn't work on any of the Fedora, Debian or Ubuntu distros to my knowledge. I just tried it and it's not in the procps-ng package that provides top. There are many implementations of top so one needs to pay special attention to which they use.
In general it's best to use free with switching to get the amount of memory free on Linux.
procps vs. procps-ng
You might have noticed that on CentOS 5 & 6 as well as RHEL 5 & 6 that top -M appears to work. This is because those distros ship with the original version of procps. The project was forked and there is now another project procps-ng.
Some of the details as to why there was a fork, from the Fedora Project's page.
excerpt
Old (legacy) procps tools had no updates for several years and that led to a massive code split caused by a local-only application of distribution specific patches, which were not merged upstream. The project became hardly maintainable since some of the newly written patches were incompatible with sources maintained by other distributors. A similar incompatibility could be noticed in the applications behavior and their command line switches. This inevitable update can be understood as an effort to unify the procps tools across all Linux distributions.
So to be clear, the forked project, procps-ng is what Debian, Fedora, Ubuntu, and other distros are using, the legacy project, which does support top -M is still in use of several of the longer term releases that don't keep up with the latest and greatest.
NOTE: I downloaded the latest version of procps-ng, "procps-ng version 3.3.9.1-14ef" and it too was lacking the -M switch.
$ ./top/top -version
procps-ng version 3.3.9.1-14ef
Usage:
lt-top -hv | -bcHiOSs -d secs -n max -u|U user -p pid(s) -o field -w [cols]
free
In running free with switches, you can see the most likely reason as to why the lack of units feature is missing from procps-ng's implementation of top.
$ free -m
total used free shared buffers cached
Mem: 7782 6506 1276 0 504 1726
-/+ buffers/cache: 4274 3507
Swap: 7823 1429 6394
[saml@greeneggs ~]$ free -k
total used free shared buffers cached
Mem: 7969492 6663180 1306312 0 516948 1764780
-/+ buffers/cache: 4381452 3588040
Swap: 8011772 1463456 6548316
Rounding becomes problematic, so I believe, procps's implementation avoids the issue by not offering the ability.
htop
Does an OK job of showing aggregate memory usage.
atop
In my opinion a better tool for looking at memory.
nmon
Another useful tool is nmon for looking at system performance.
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2@AnthonyAnanich - I researched this a bit more. CentOS 5.4's top version "procps version 3.2.8" has the
-Mswitch, CentOS 5.8, also has this switch, "procps version 3.2.7". However Fedora 19 has "procps-ng version 3.3.8" which doesn't support the-Mswitch. – slm♦ Dec 19 '13 at 22:07 -
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Great answer, thank you, @slm. I even do not know which of the three answers is the best. Will not award to anyone, I want let other people decide. – Anthony Ananich Jan 22 '14 at 11:11
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@AnthonyAnanich - NP. You should consider picking one if you feel that it answers your Q 100%. Accepting an A is important since it signals to the rest of the community that passes by your Q that you as the OP felt this A answered or solved your particular issues. If other A's are outstanding they'll get UV'd as well. Not accepting one, is basically a signal that you as the OP still feel your Q hasn't bee sufficiently answered. The accepted A also gets positioned as the 1st A when ppl see your Q in the future. – slm♦ Jan 22 '14 at 12:59
You can press the following keys:
- e -- Change the scaling factor on the summary display
- Shift+e -- Change the scaling factor on the task
- Shift+w -- Save current settings
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So the quick answer : depending on your linux distro, try either :
top -M
OR, after starting top, type capital E (then W to write the config).
One of those should work for nearly everybody (except Solaris, of course, where you'd be lucky to have top at all).
bonus tip : every time you start a top instance on a new install, type ExyzW to save colours and highlighting and units - what a relief!
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You can use the command line option E to specify the memory scaling, for example in gigabytes:
$ top -E g
From the top help:
-E :Extend-Memory-Scaling as: -E k | m | g | t | p | e
Instructs top to force summary area memory to be scaled as:
k - kibibytes
m - mebibytes
g - gibibytes
t - tebibytes
p - pebibytes
e - exbibytes
Later this can be changed with the `E' command toggle.
OS: Ubuntu 20.04
On RHEL7 top shift + e or CspsLK ON. You need " E " capital alphabet.
You will get in MiB, Gib, TiB, PiB, EiB. All these you can access.
And also you can you htop command which should be downlaoded and installed on rpm base system.
Thank you. Sagar Dalvi
top -Mto display the usage in MB. If you only want to monitor the memory usage, you can use rather usehtop. Not sure of any other option. – Barun Dec 19 '13 at 15:54free -m, or betterfree -hinstead. – terdon♦ Dec 19 '13 at 16:48Euntil it shows the memory cumulative you're looking for, then hitWto write that configuration to disk. – Trevor Norris Apr 13 '15 at 2:07