In computing, memory refers to the state information of a computing system, as it is kept active in some physical structure.

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What's exactly Compile time, Load time, and Execution time? [closed]

It's said, Compile time -- When it is known at compile time where the process will reside, compile time binding is used to generate the absolute code. Here I'm not sure what is the absolute code? ...
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189 views

Preventing a new instance of a program to open when calling it

My problem is with FBI (frame buffer image viewer) for Linux, but my question and any answers are perhaps applicable to more than only that program. I don't know. Anyway… While things are loading on ...
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Amount of memory transfer on a running Linux

Can I determinate the amount of RAM exchange (between the CPU and the RAM) on a running Linux system? I'm not looking for the max RAM speed (then memtest would be valid answer). I'm looking for the ...
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623 views

Java/malloc memory corruption error when running SDK Android Manager

I want to install Android SDK, so I manually installed Java JDK 7u51, downloaded SDK ADT bundle for Linux x64, and tried to run it. When I run android, the SDK manager windows hangs halfway through ...
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55 views

Is this method safe or recommended for moving a /home directory?

I have my linux install on a small disk. I want to put the home directory on a different hard-drive. I was thinking of using this and then this. Would this work? Is there a better way? Should I just ...
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1answer
260 views

Is there something wrong with df output? [duplicate]

I'm using the command df -h to check disk usage on CentOS 6.4. I see an inconsistency with the output. look at the line Filesystem: total 490Gb, used 55Gb, and Available 411Gb. What is it mean? I ...
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Memory usage on SunOS and Linux

I have some doubts with memory usage. Currently I have nagios check who measures used memory from free -m command on Linux. I added another script for memory usage from ...
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1answer
474 views

Why do the data and code segments completely overlap in Linux?

Context: I'm reading "Understanding the Linux kernel, 3d ed", which uses the 2.6.11 kernel. Question: As I understand, the physical address is obtained by translating the linear address, which is ...
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memory consumption alert

My VPS has reported a memory consumption alert says reached 273% and I cannot access any of my sites. But I checked on the terminal today and it does not look like a memory problem. Am I correct in ...
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94 views

Loading a kernel driver to a specific memory address

How can I load a kernel driver at a specific memory address? How could it be done with the following methods? commands/scripts like insmod or modprobe using C code (not sure if there may exist ...
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1answer
908 views

Is it possible to find the physical address range of a DIMM?

I note that SMBios Type 20 would help here, but it's optional as of version 2.5 (2006-09-05) pp. 25, L796, and pp. 131, whereas types 16, 17 and 19 are mandatory, but don't quite help. Physical ...
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1answer
900 views

Worker MPM or Prefork?

I understand that there is a comparison topic between the two modules but this is different. I was contacting cPanel support in order to help me freeing up some memory usage on the VPS. They found ...
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3answers
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Linux empty buffer cache command permission denied

I'm using the following commands to flush cache: # sync; echo 3 > /proc/sys/vm/drop_caches # sync; echo 2 > /proc/sys/vm/drop_caches # sync; echo 1 > /proc/sys/vm/drop_caches When I use ...
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2answers
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Securely viewing an encrypted file

I have a file that is gpg encrypted. I would like to view the content of the file, but leave no trace of the output. Lets say for example that the encrypted file has some passwords, and I don't want ...
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1answer
442 views

How to see buffered and cached data

~$ free total used free shared buffers cached Mem: 3891076 1044972 2846104 0 82744 463876 -/+ buffers/cache: 498352 3392724 ...
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3answers
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How can I find the amount of memory consumed by a process?

How can I find the amount of main memory consumed by a process using ps aux? I have a process which runs for half an hour. Is it possible to find the maximum amount of main memory consumed by it ...
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How to display meminfo in megabytes in top?

Sometimes it is not comfortable to see meminfo in kilobytes while you have several gigs of RAM. In Linux it looks like that: And here is how it looks in Mac OS X: Is there a way to display ...
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The meaning of output of pmap

I wrote main.c in Linux: int main() { while (1){} } When I compile and start it, I can pmap it: # pmap 28578 28578: ./a.out 0000000000400000 4K r-x-- /root/a.out 0000000000600000 4K ...
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1answer
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HDD indicator blinks when I run out of memory, but I have no swap configured [duplicate]

I'm running Arch Linux, with 8 GB memory and no swap defined. Sometimes it ran out of memory, then my system get a little bit stuck, and I can see the HDD indicator blinking. Then I restart X, which ...
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2answers
190 views

Linux-swap on reboot

I'm wondering what actually happens to a Linux-swap partition reboot. I've been taking a course in computer organization and while installing/partitioning a new drive I became rather curious about ...
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1answer
76 views

How to create memory-based disk in linux? [duplicate]

I need to have a very fast disk for keeping cache. How can I do that in Linux?
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1answer
105 views

Limiting processes by memory under Linux

We must launch several hungry processes on a Linux system. These processes often need several Go (~5Go) of memory to run (total memory: 16Go RAM + 2Go swap). At first, when the system was running ...
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546 views

CentOS memory allocation

I was running my VPS with CentOS on 1G memory, but I saw the memory was getting "full" so I had 1G extra installed. This VPS is one I rent at a hosting company. That company did most of the ...
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Writing to Arbitrary Memory Addresses [closed]

I'm reading "Art of Exploitation 2nd Ed." and I have a question regarding a section on format string attacks. Target program Below code (fmt_vuln.c) is a target program. #include <stdio.h> ...
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2answers
359 views

Swap bash script pins htop's memory usage

I deployed a hack to add swap space to a VPS that otherwise didn't allow me to use swapon to create a file. Prior to adding and executing the script, I followed the steps outlined here. and ...
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11answers
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How to fill 90% of the free memory?

I want to do some low-resources testing and for that I need to have 90% of the free memory full. How can I do this on a *nix system?
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2answers
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lsof - debug the output information

I was going through the questions of this site. In this particular question, I see the command lsof being used to list the files that are open for a particular user. I ran the below command in my ...
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557 views

Spike in swap utilisation without high swap rate

Every Saturday, for reasons unknown to me, one of my servers experiences a spike in swap utilisation. It's not necessarily a problem as there is plenty of free memory available, but I'd still like to ...
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1answer
982 views

Know when a memory address is aligned or unaligned

Im getting kernel oops because ppp driver is trying to access to unaligned address (there is a pointer pointing to unaligned address). Im not sure about the meaning of unaligned address. It means not ...
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2answers
218 views

How does a process handle the situation when it finds no memory to use?

What happens when a particular process finds that there is no memory to use? Will that process kill/restart another process to proceed their task ? Or what the process (that requires more memory) ...
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1answer
170 views

Running git with higher memory allocation

I am facing memory/data segment issues while running git. However, if I set my ulimits to a bit higher like below. ulimit -m 262144 ulimit -d 262144 It runs fine. Don't we have anyway to allocate ...
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1answer
1k views

Excessively high memory usage reported (3 GB) after reboot

Brief problem description: A 64-bit Gentoo on Intel Core-2 Q6600 reports about 3GB used out of 8GB total memory after reboot. This memory is neither claimed by any process, nor is it used by ...
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695 views

Copying large file causes excessive swap

On a mid-class CentOS 6.4/64 server with 32 GB RAM, 3 TB free disk space, operating as KVM hypervisor, I start copying a 200 GB file to a destination in the same local filesystem. In fact, this file ...
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622 views

How to monitor average stats of CPU and memory usage of a Solaris server using scripts?

I need to monitor average CPU and memory usage for a Solaris server. How can I automate the process using scripts to monitor daily CPU and memory usage and give it as an average over a month?
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2answers
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Need help with a script to test for memory usage [closed]

I'm trying to put up a temporary band-aid while I work out a solution for a app's memory leak. What I wrote was a small bash script that I put in the root on the server. This is what the script is ...
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615 views

Linux kernel with absolutely no virtual memory [duplicate]

I am interested in obtaining (or building myself) a version of the Linux kernel that has absolutely no virtual memory and none of its attendant overhead. No swap file, no nothing. What are my ...
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3answers
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How can memtest check all memory while it is still loaded?

Inspired by this question. If you're testing your memory, you have to test all memory - you shouldn't trust any of it to be good. How can memtest effectively do this when memtest itself will consume ...
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Does segfaults mean bad memory

This is a brand new server with a new install and fresh compile of Apache/PHP with nothing crazy. Just a WordPress site hosted and I get the following. Could this just mean bad RAM? If so how can I ...
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when awake from hibernate, will the VIRT column of top command show the swap space used by process?

top - 10:43:31 up 8 days, 1:28, 4 users, load average: 0.72, 0.57, 0.44 Tasks: 180 total, 1 running, 177 sleeping, 0 stopped, 2 zombie %Cpu(s): 8.9 us, 2.1 sy, 0.0 ni, 88.9 id, 0.0 wa, ...
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1answer
260 views

No virtual memory (-v) item in output of ulimit -a

When I run command ulimit -a, I see no virtual memory item in the list of output of the command. It is unlimited for some user IDs though. Does that mean I am assigned no virtual memory?
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978 views

Memory usage command with syntax similar to the time command

What command shows the memory usage of a program, i am looking for a command that is simple to use and has similar syntax to the time command. I am trying to find the memory usage of a md5 hashing ...
25
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3answers
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grep: memory exhausted

I was doing a very simple search: grep -R Milledgeville ~/Documents And after some time this error appeared: grep: memory exhausted How can I avoid this? I have 10GB of RAM on my system and few ...
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1answer
256 views

32-bit on 64-bit: memory usage for multiple processes

I'm working on a Linux hosting solution for game server software, however the software in question is 32-bit and I'd be running 64-bit on the host. Now, I know I can run 32-bit apps on a 64-bit host ...
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2answers
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swapoff fails when overcommit_memory==2

I've disabled memory overcommitting by setting overcommit_memory=2. Now when I tried to swapoff, I get this error: swapoff: /dev/sda5: swapoff failed: Cannot allocate memory But I in fact have 0 ...
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1answer
411 views

Static files give ever changing checksum value on Linux

When I cksum large files (150MB) they will often report different checksums on each call. $ cksum test3 1233504235 170213376 test3 $ cksum test3 825031809 170213376 test3 $ cksum test3 189847968 ...
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Does sync command remove the dirty cache in the memory?

I am aware that sync command flushes the dirty cache into disk. I have run free command first, then sync, and then free again. The result of latter free command shows more free memory available than ...
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Viewing virtual memory usage

I started 700+ threads from a single program And my /proc/[PID]/status file shows the following output. VmPeak: 7228104 kB VmSize: 7228104 kB VmLck: 0 kB VmHWM: 3456 kB VmRSS: ...
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very high buffer memory usage [closed]

Is this normal - I've never seen buffers so high? $ cat /proc/meminfo MemTotal: 16332808 kB MemFree: 1112264 kB Buffers: 10630124 kB Cached: 699400 kB SwapCached: 0 kB Active: 3262924 kB Inactive: ...
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2answers
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a handy tool to measure memory consumption of a program [duplicate]

I develop a C code on Debian. I am looking for a program to monitor memory consumption of my code in real-time. The only value I care is the maximum RAM consumption, it should hold the value even if ...
3
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/proc/meminfo MemTotal =?

What elements of /proc/meminfo sum up to MemTotal? Example of tee /tmp/proc/meminfo < /proc/meminfo MemTotal: 1279296 kB MemFree: 164092 kB Buffers: 62392 kB Cached: ...