Above is the output of 'free -m' from my linux machine. I did some searching on the internet and some of the articles point that linux is memory hungry ( not that it use up memory very fast, but it will use what is available). In my case, what is the free RAM i have? 46M or 518M. I highly do not think that its 46M + 518M.
The used and free Mem adds up to 1010 ( 963 + 46)
I am quite buffled by the -/+ buffers/cache value, the used and free values also adds up to 1010.
so linux is telling me it has used up 963MB of ram and 46MB is still available but on the other hand, it has 491 used in the buffer and 518 in the buffer is free... *confused and curious*
My total physical ram is 1GB. Would appreciate if anyone can explain and 'de-mysterifiy' me.
when /var directory of my machine gets filled up (85%) i removed some old logs. but after cleaning df -k command still shows that /var is still 85% full.
It can detect the actual disk space only after I restart the machine. Is there a way to force df to reflect actual free space without... (1 Reply)
Hi All,
I have a pair of sun ultra 5_10 with SunOS 5.5.1.
Both are almost equally patched and set up with simillar applications.
host# uname -a
SunOS host 5.5.1 Generic_103640-24 sun4u sparc SUNW,Ultra-5_10
Even though both have
same amount of RAM ( 512 Mb ) ,
... (1 Reply)
What's the best way to find out how much memory is being used/available? I tried using free, but I didn't quite understand the output. Can someone explain it?
$ free
total used free shared buffers cached
Mem: 16304536 16256376 48160 0 ... (6 Replies)
I am trying to write a small (and rather simple) script to gather some info about the system and piping it to dzen2
first, i want to explain some things.
I know i could have used conky, but my intention was to expand my knowledge of bash, pipes and redirections inside a script, and to have fun... (14 Replies)
how can I find cpu usage memory usage swap usage and
I want to know CPU usage above X% and contiue Y times and memory usage above X % and contiue Y times
my final destination is monitor process
logical volume usage above X % and number of Logical voluage above
can I not to... (3 Replies)
Hi all,
I'm running a simulator and I'm noticing an slow increase in memory for long simulations such that the simulation has to end because of a lack of memory. A colleague of mine ran Valgrind memcheck and reported that nothing of interest was reported other than known mem leaks. My advisor... (2 Replies)
I recently started working with Linux and wrote my first device driver for a hardware chip controlled by a host CPU running Linux 2.6.x kernel.
1. The user space process makes an IOCTL call with pointer to a user memory buffer.
2. The kernel device driver in the big switch-case of IOCTL,... (1 Reply)
hi , I have a problem about getgroups usage on linux. getgroups can get supplementary groups of a process but if i run a process with root account and I want to get supplementary groups of nobody then what i should do to realize that. (4 Replies)
Hi,
I'm looking into doing a few performance tweaks by adjusting my max memory on a few lpars.
I would to create a time stamp script so i could review it for a week and determine how much space i can lower my max memory to so i could reclaim and allocate that memory to where it is needed the... (2 Replies)
Discussion started by: vpundit
2 Replies
LEARN ABOUT PLAN9
free
FREE(1) User Commands FREE(1)NAME
free - Display amount of free and used memory in the system
SYNOPSIS
free [options]
DESCRIPTION
free displays the total amount of free and used physical and swap memory in the system, as well as the buffers and caches used by the ker-
nel. The information is gathered by parsing /proc/meminfo. The displayed columns are:
total Total installed memory (MemTotal and SwapTotal in /proc/meminfo)
used Used memory (calculated as total - free - buffers - cache)
free Unused memory (MemFree and SwapFree in /proc/meminfo)
shared Memory used (mostly) by tmpfs (Shmem in /proc/meminfo)
buffers
Memory used by kernel buffers (Buffers in /proc/meminfo)
cache Memory used by the page cache and slabs (Cached and SReclaimable in /proc/meminfo)
buff/cache
Sum of buffers and cache
available
Estimation of how much memory is available for starting new applications, without swapping. Unlike the data provided by the cache or
free fields, this field takes into account page cache and also that not all reclaimable memory slabs will be reclaimed due to items
being in use (MemAvailable in /proc/meminfo, available on kernels 3.14, emulated on kernels 2.6.27+, otherwise the same as free)
OPTIONS -b, --bytes
Display the amount of memory in bytes.
-k, --kibi
Display the amount of memory in kibibytes. This is the default.
-m, --mebi
Display the amount of memory in mebibytes.
-g, --gibi
Display the amount of memory in gibibytes.
--tebi Display the amount of memory in tebibytes.
--pebi Display the amount of memory in pebibytes.
--kilo Display the amount of memory in kilobytes. Implies --si.
--mega Display the amount of memory in megabytes. Implies --si.
--giga Display the amount of memory in gigabytes. Implies --si.
--tera Display the amount of memory in terabytes. Implies --si.
--peta Display the amount of memory in petabytes. Implies --si.
-h, --human
Show all output fields automatically scaled to shortest three digit unit and display the units of print out. Following units are
used.
B = bytes
K = kibibyte
M = mebibyte
G = gibibyte
T = tebibyte
P = pebibyte
If unit is missing, and you have exbibyte of RAM or swap, the number is in tebibytes and columns might not be aligned with header.
-w, --wide
Switch to the wide mode. The wide mode produces lines longer than 80 characters. In this mode buffers and cache are reported in two
separate columns.
-c, --count count
Display the result count times. Requires the -s option.
-l, --lohi
Show detailed low and high memory statistics.
-s, --seconds delay
Continuously display the result delay seconds apart. You may actually specify any floating point number for delay using either .
or , for decimal point. usleep(3) is used for microsecond resolution delay times.
--si Use kilo, mega, giga etc (power of 1000) instead of kibi, mebi, gibi (power of 1024).
-t, --total
Display a line showing the column totals.
--help Print help.
-V, --version
Display version information.
FILES
/proc/meminfo
memory information
BUGS
The value for the shared column is not available from kernels before 2.6.32 and is displayed as zero.
Please send bug reports to
<procps@freelists.org>
SEE ALSO ps(1), slabtop(1), top(1), vmstat(8).
procps-ng 2016-06-03 FREE(1)