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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How the network packets are transferred to the memory on linux?

Is there some command or tool for monitoring network packets and how those packets are handled by the memory and than proceeded to the CPU on linux platform? Using tcpdump I can capture many apache ...
0
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1answer
9 views

Configure the OOM to avoid having the system grind to a halt

I have an SSD and therefore no swap. However, when I open a lot of tabs in the browser, the system tends to grind to a halt. If I'm lucky, I can close one or two tabs before the system is completely ...
2
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0answers
65 views

Debian 64-bit sees less than 4GB of RAM

I have a Debian wheezy (7.4) amd64 virtual machine running under VirtualBox 4.3.10 on a Win7 x64 host with AMD A10-5700 processor. The virtual machine is configured with 16GB of memory (the host has ...
1
vote
1answer
70 views

Why is swap used when a lot of memory is still free? [duplicate]

In the below 2.6.18 Linux Kernel (Red Hat) server, there is a lot of free memory, but I see some swap is used. I always thought of swap as an overflow when memory has been depleted. Why would it ...
0
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1answer
51 views

Can continually assigning a variable in a shell script cause a memory leak?

I've written a short script to copy Apache's server status to a log: #Save date and time to a variable dt=$(date) #Echo date and time to the log file as it's not included in server-status echo "Time ...
0
votes
1answer
20 views

Having an independent console to kill rogue process?

Sometimes a flash plugin starts using all the mem and CPU or an app is also behaving "naughtily" and my system starts to crawl until i finally get a terminal with htop up and kill the rogue process, ...
1
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0answers
17 views

What is the structure of Libvirt Qemu VM dump/save files?

I need to do some exploration of Qemu-KVM virtual machines physical memory (particularly I need to check the fact of the physical memory intersection). In order to do that I'm trying to save VM's ...
2
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0answers
20 views

Set up OS and Runnig app using x32-ABI

Intro I just moved to a 64bit installation and I'm experiencing big difference in memory usage ( especially for app like chrome, firefox, mysql and java apps ): - While before 4gb were enough now they ...
0
votes
1answer
26 views

What happens to the files when they are being decrypted?

I have the server's webroot directory mounted on a partition which is being protected with LUKS encryption. I want to know what happens to the files within when that partition is being decrypted. Does ...
2
votes
0answers
29 views

Automatically memtest and then boot

Is there some way to reboot server, so it runs memtest (say, 1 or 2 passes) and then reboots back to Linux and writes report to some log? This feature in Windows Server 2012 helped me to diagnose bad ...
9
votes
2answers
138 views
+100

On system memory… specifically the difference between `tmpfs,` `shm,` and `hugepages…`

I've been curious lately about the various Linux kernel memory based filesystems. Note: As far as I'm concerned, the questions below should be considered more or less optional when compared with a ...
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0answers
27 views

About the usage of Memory in a linux server [duplicate]

I find my server's memory usage is so high, part of the output of command free is shown below: total used free shared buffers cached Mem: 82446460 81961412 ...
1
vote
1answer
106 views

How to dump memory image from linux system?

I know to dump memory images in Window. (eg-dumpit) But I don't know how to dump memory images in Linux. I wanna get memory images in Linux and from linux to linux with ssh connection or something. ...
3
votes
1answer
35 views

program executing for 2 days

I have a java program which implements the Hungarian algorithm. I made changes to the existing code in such a way that the input is read from file. I have a pretty huge input around 32,000 rows for ...
7
votes
7answers
897 views

cron Vs. sleep - which is the better one in terms of efficient cpu/memory utilization?

The Case: I need to run some commands/script at certain intervals of time and for this I have two options - 1. set up a cron-job or, 2. implement a loop with sleep in the script itself. Question: ...
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0answers
25 views

Set memory allocation for applications in Ubuntu [duplicate]

I have an application running under Ubuntu that tries to consume all available memory. Is there a way to specify and restrict the allocations available for a given application?
0
votes
0answers
53 views

How to cause memory fragmentation on a Linux based embedded device?

Hardware ARM What am I trying to do: Answer: I am trying to create memory fragmentation on a Linux 2.6.31 based swapless embedded device. Why: Answer:I am trying to port some patches to Linux ...
2
votes
0answers
53 views

Why does the kernel boot faster with less memory allocated?

This is not a important question, I'm just curious. Something strange happened, which isn't quiet clear to me: In the kernel command line, the amount of the memory can be set statically with the ...
4
votes
3answers
86 views

What happens in UNIX/Linux when a program is bigger then size of memory?

I was wondering how embedded systems are able run programs bigger than the size of memory. If I had 1 GB of memory and the program was 1.5 GB, would the program load? Are there systems that only use ...
2
votes
2answers
45 views

Are limits in linux (like those controlled by ulimit or /etc/security/limits.conf) per user or per user per process?

I saw three copies of a process running and one of them cored in what seems like memory issue. Each individually occupies about 3-4 GB of memory..would a limit account for killing one of them? And if ...
16
votes
1answer
1k views

What is maximum RAM supportable by Linux?

What is the maximum supportable RAM by Linux? Assume that hardware is/supports 64-bit. Among all Linux distros. Does it go up to 16 exabytes, or is it limited like with Windows which I believe is 192 ...
10
votes
1answer
226 views

Loading of shared libraries and RAM usage

I'm wondering about the way Linux manages shared libraries. (actually I'm talking about Maemo Fremantle, a Debian-based distro released in 2009 running on 256MB RAM). Let's assume we have two ...
3
votes
1answer
88 views

Optimised ZFS in low RAM environment feasibility?

I am currently setting up a file server and have come to the point of actually setting up the data drives. The system has 4 drives (one OS disk, 3 data disks). The OS disk is formatted as ext4 and ...
0
votes
1answer
44 views

mdadm large memory consumption [closed]

I am building a RAID 6 with mdadm (8 WD Red 3 Tb) on Ubuntu 13.10x64 server with ext4 filesystem. When I download torrent on the array, server RAM is filled for maximum cap (8 Gb) memory is free when ...
2
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2answers
207 views

How to remove cache device from bcache?

I believe, that once I made sure my cache device state is "clean": $ sudo cat /sys/block/bcache0/bcache/state I can just physically remove it from the machine when it is powered off or boot with ...
1
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0answers
71 views

dovecot. Can't allocate memory, but free -m show available memory

I trying to send mail with PHP (engine - Drupal). But it can't send mail and write message about it in to log (nothing more that adressed). Part of /var/log/mail.err : Feb 14 19:55:30 hivede13-3220 ...
1
vote
1answer
210 views

How to reduce ClamAV memory usage?

I'm running a Ubuntu based web server (Apache, MySQL) on a 512MB VPS. This is more than sufficient for the website it is running (small forum). As I wanted to add some protection against viruses I ...
3
votes
3answers
173 views

Why does MemTotal in /proc/meminfo change?

I monitor value from /proc/meminfo file, namely the MemTotal: number. It changes if a ram module breaks, roughly by size of the memory module - this is obvious. I know the definition for the field ...
0
votes
1answer
53 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
17 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
13 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 ...
0
votes
1answer
205 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 ...
0
votes
1answer
39 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
44 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
204 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
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0answers
21 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
68 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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0answers
32 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
54 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 ...
3
votes
1answer
156 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 ...
1
vote
1answer
84 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
282 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 ...
2
votes
2answers
44 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
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1answer
99 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
3answers
80 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 ...
6
votes
3answers
2k views

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 ...
5
votes
1answer
261 views

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 ...
0
votes
1answer
33 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
51 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
45 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?