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

learn more… | top users | synonyms

1
vote
1answer
697 views

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? ...
0
votes
1answer
75 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 ...
1
vote
0answers
16 views

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 ...
73
votes
11answers
29k views

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?
4
votes
2answers
989 views

Is it possible to trigger OOM-killer on forced swapping?

Is it possible to have the system preemptively swap out inactive pages (vm.swappiness), but invoke the oom-killer when the system runs out of RAM (as opposed to running out of memory) and is forced to ...
18
votes
1answer
13k views

Getting information about a process' memory usage from /proc/pid/smaps

For a given process in /proc/<pid>/smaps, for a given mapping entry what are: Shared_Clean Shared_Dirty Private_Clean Private_Dirty Is Shared_Clean + Shared_Dirty the amount of memory that ...
0
votes
1answer
44 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 ...
0
votes
1answer
117 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 ...
0
votes
2answers
4k views

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 ...
0
votes
0answers
34 views

How to install memusg tool

I've tried with yum install memusg but returned: Loaded plugins: fastestmirror, security Setting up Install Process No package memusg available Error: nothing to do Any solution
4
votes
1answer
243 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 ...
1
vote
0answers
40 views

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 ...
-2
votes
1answer
77 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 ...
5
votes
3answers
652 views

Is it possible to support multiple processes without support for Virtual memory?

Is it possible to support multiple processes without support for virtual memory? I would like to know more about it if so.
1
vote
1answer
428 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 ...
1
vote
1answer
963 views

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 ...
4
votes
1answer
1k views

How can I tell what memory RAM address range is being used by uboot?

I am in uboot and was wondering, how could I tell what RAM address range is being used by uboot. uboot needs memory to run so it might be using some of the RAM. I want to avoid modifying those RAM ...
2
votes
2answers
57 views

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 ...
1
vote
1answer
237 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 ...
2
votes
2answers
794 views

Need help with a script to test for memory usage

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 ...
2
votes
3answers
278 views

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 ...
17
votes
2answers
3k views

How to blacklist a correct bad RAM sector according to MemTest86+ error indication?

MemTest86+ (the version included with Ubuntu 13.04) says Failing address: 002f796c48 - 759.5 MB What should I specify in the memmap kernel parameter to bypass this area? I've tried running ...
0
votes
1answer
39 views

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 ...
2
votes
2answers
100 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 ...
0
votes
1answer
66 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?
6
votes
3answers
9k views

Swap usage too high?

I have a debian sid box, freshly installed about a month ago, with no desktop apps running at the moment. Any command I try to run (via ssh) makes the hard disk work very hard. The system worked ...
55
votes
5answers
26k views

What are high memory and low memory on Linux?

I'm interested in the difference between Highmem and Lowmem: Why is there such a differentiation? What do we gain by doing so? What features does each have?
1
vote
0answers
349 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 ...
2
votes
0answers
162 views

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> ...
1
vote
2answers
254 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 ...
4
votes
1answer
288 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 ...
15
votes
2answers
1k views

Linux: Total swap used = swap used by processes +?

So, I'm trying to do some investigation on where does swap use come from in a system with high swap usage: # free total used free shared buffers cached Mem: ...
2
votes
2answers
241 views

How to reuse Physical memory in the absence of swapping?

How can I reuse physical memory in the absence of swapping?
2
votes
2answers
1k views

gnome-keyring-daemon couldn't allocate secure memory

I run logcheck on my Debian Linux system to get alerted to unusual lines in my log files, and recently I saw the following in /var/log/messages: gnome-keyring-daemon: couldn't allocate secure memory ...
2
votes
2answers
300 views

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 ...
2
votes
1answer
404 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 ...
6
votes
2answers
1k views

What is “kernel dynamic memory” as reported by smem?

While diagnosing low memory problems in my desktop machine (details at U&L) I've noticed that my noncache "kernel dynamic memory" is big: # smem -twk Area Used ...
2
votes
2answers
168 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) ...
0
votes
1answer
99 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 ...
3
votes
0answers
754 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 ...
4
votes
2answers
433 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 ...
0
votes
2answers
487 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?
0
votes
2answers
287 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 ...
1
vote
1answer
201 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 ...
2
votes
3answers
105 views

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, ...
1
vote
3answers
813 views

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 ...
4
votes
1answer
1k views

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 ...
0
votes
1answer
178 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?
21
votes
3answers
3k views

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 ...
4
votes
2answers
487 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 ...