11-14-2014
the min is for minimum cache: whatever memory reclamation is buffers wont go under that value...
So max is to be understood as the maximum buffer cache you let the system have, if there is memory not used that is where it will finish to the value given...
It could release for other programs to do but for that it needs to flush the cache before and that can take some time because lets say it is of 50% of your 24GB that means forcing a 12 GB of immediate write to disk, will / How the SAN cope with that? usually you see in such case a "freeze" of the system ( you know you type and nothing is happening ...) till done... that is why it is resonable to configure that value to what you know you SAN can accept without any trouble ( that means SAN can send an acknowlege almost just after so the buffers can be flushed...)
The system hates to have wasted RAM so if you have unused RAM either it will be used as pseudoswap, or will end as cache unless you dont let it use it ( by reducing e.g dbc_max_pct ...).
If you have JAVA stuff that could run and you are just a little short ( used by cache...) it wont wait for it to be released and exit saying not enough memory...
This User Gave Thanks to vbe For This Post:
10 More Discussions You Might Find Interesting
1. AIX
Hi am facing high cpu utilization on my sybase server.
I have P550
Number Of Processors: 4
Processor Clock Speed: 1656 MHz
CPU Type: 64-bit
Kernel Type: 32-bit
LPAR Info: 1 65-D837E
Memory Size: 7840 MB
in topas it shows
Name PID CPU% PgSp Owner
dataserv 565264 ... (1 Reply)
Discussion started by: vjm
1 Replies
2. Shell Programming and Scripting
Hi Unix Gurus i am somewhat new to unix scripting so need your help to
create a script as below.
# This script would find the process consuming memory beyond a certain #limit. if the meemory consumption is more than 100% for a period of 1
# minute for the specific process. the script would... (0 Replies)
Discussion started by: robinforlinux
0 Replies
3. AIX
Hi,
i have two oracle instances running on my server with 7.5G RAM but it is showing almost 99% memory is full as you can see bellow.
# svmon
size inuse free pin virtual
memory 1974272 1954270 20002 336595 1800652
pg space 4194304 ... (7 Replies)
Discussion started by: salmanucit
7 Replies
4. AIX
How to find the memory utilization of AIX server using svmon -G output.
Sample output for svmon -G command from my AIX test server,
size inuse free pin virtual
memory 4014080 3995443 18637 575916 1876393
pg space 1179648 ... (3 Replies)
Discussion started by: maruthu
3 Replies
5. Red Hat
Hello All,
We have a jave server running on both linux and Solaris environments.
On solaris,it consumes only 600-700MB whereas it goes upto 21G in Linux.
I am monitoring the memory consumption through top command.
Is this high memory consumption expected in Linux? (1 Reply)
Discussion started by: prasperl
1 Replies
6. Solaris
Hi Experts,
Our servers running Solaris 10 with SAP Application. The memory utilization always >90%, but the process on SAP is too less even nothing.
Why memory utilization on solaris always looks high?
I have statement about memory on solaris, is this true:
Memory in solaris is used for... (4 Replies)
Discussion started by: edydsuranta
4 Replies
7. Solaris
Hello Guys,
I have one Solaris server with high memory utilization >90%. As per checking, below is the output for memory usage.
bash-3.00# ps -efo pmem,uid,pid,ppid,pcpu,comm | sort -r
%MEM UID PID PPID %CPU COMMAND
1.7 29496 20668 1 0.0 /opt/app/iw-home/tools/java/bin/java
1.5... (1 Reply)
Discussion started by: myrpthidesis
1 Replies
8. Red Hat
Hi All,
I have a java process which is showing high virtual memory utilization in client server. But the same process is showing comparitively lesser virtual memory consumption. I understand that virtual memory shown is not of much importance for the general user in normal condition, my client... (2 Replies)
Discussion started by: mritusmoi
2 Replies
9. Red Hat
Hi,
i am new to linux/RHEL 6.0 and i have two questions.
1) How to get the CPU utilization and Memory Utilization of all Services running currently?
2) How to get the CPU utilization and Memory Utilization of all Applications running currently?
Please help me to find the script.
... (2 Replies)
Discussion started by: nossam
2 Replies
10. UNIX for Advanced & Expert Users
Hi Fellas,
Not sure how I can dig in even further but we notice that one of our DB servers is showing high Sys% CPU usage even though when I execute the following command :
I can see that postgres is the only one using the CPU. So if anyone can advise me what would be the best way to... (3 Replies)
Discussion started by: arizah
3 Replies
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)