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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3answers
16k views

How to Determine the Amount of RAM Slots In Use?

I forgot how many RAM modules are installed on my laptop. I do not want to unscrew it but want to look it up on the console using bash. How do I gather this information?
3
votes
2answers
5k 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 ...
0
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0answers
28 views

Storage allocator out of space error on unix shell script

While running the script called abc.sh, following errors are thrown. abc.sh: line 226: storage allocator out of space on 64946176 byte request ( region 64329285632 segments 1981 busy ...
0
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0answers
28 views

Why process is killed while a lot of memory is free?

I am running a python script in ipython. This script will take about 8GB RAM. The system has more than 80 GB free RAM but the swap is nearly 0. My script was killed after it runned for a while. I want ...
54
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4answers
60k views

How to display `top` results sorted by memory usage in real time?

How can I display the top results in my terminal in real time so that the list is sorted by memory usage?
1
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1answer
20 views

Can I trust in memory information of dmicode?

I want to buy 16gb memory for my notebook. I ran dmicode and found this information: Handle 0x0005, DMI type 5, 20 bytes Memory Controller Information Error Detecting Method: None ...
1
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2answers
596 views

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 ...
5
votes
1answer
997 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 ...
0
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0answers
6 views

/proc filesystem - getting useful information

I'm trying to understand the values in /proc/PID/status. I want to calculate cpu% & mem% used by PID, similar to top bash command. For Memory percentage usage I can do the following (correct me ...
3
votes
1answer
32 views

Resource (CPU time and memory) limitation and termination of a process upon violation in Linux

The problem: Given a process, limit the resources it and its child-processes can use. I.e. set CPU time and virtual memory quotas. When the process group exceeds one of the limits, terminate it, ...
0
votes
1answer
651 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 ...
2
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2answers
1k views

Discrepancy between reported used memory and sum of application memory usage

I'm running a desktop system that quite regularly suffers from lack of memory, this prompted me to investigate what causes the issue in the first place. Problem is, there's no single process that ...
2
votes
1answer
43 views

What does Linux spend memory on other than userland, caches and slab?

I have a system with 1 GB of physical RAM. Right now, free shows the following memory usage: total used free shared buffers cached Mem: 1026360 863660 ...
50
votes
5answers
62k views

Limit memory usage for a single Linux process

I'm running pdftoppm to convert a user-provided PDF into a 300DPI image. This works great, except if the user provides an PDF with a very large page size. pdftoppm will allocate enough memory to ...
2
votes
0answers
34 views

Which process wrote to which memory address? [closed]

Recently, I've been seeing a wide variety of memory-related crashes at work (C++ applications on Ubuntu 14.04). Our applications use a properietary third party library to interface with real time data ...
1
vote
1answer
30 views

How to find the page size of physical memories from userspace?

I want to understand the page size, sector size, block size (if applicable) of a usb flash drive. Is there a way for me to inspect those with Ubuntu? mount /dev/sda1 /mnt ? umount /dev/sda1 Edit ...
0
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0answers
30 views

Is High Virtual Memory usage a problem or may cause problems?

In our server, we have a python based code that listen ports. The amount of Virtual Memory it uses is increased greatly with time Like: USER PID %CPU %MEM VSZ RSS TTY STAT ...
2
votes
3answers
1k views

Linux / JVM - OutOfMemoryError: unable to create new native thread

I have a memory problem with a Linux server (CentOS). It is a VM. Below is the context. It has 70Gb of RAM. There are 2 tomcat running on it. One tomcat is given a heap of 13Gb and the other one a ...
57
votes
12answers
10k views

Do I need swap space if I have more than enough amount of RAM?

From what I understand, the purpose of a swap partition in Linux is to free up some "not as frequently accessed" information from RAM and move it to a specific partition on your harddrive (at the cost ...
1
vote
0answers
14 views

How can Profile/Benchmark ram performance?

Effectively I would like to know if my memory hardware it a bottleneck of my system performance. I am dealing with really old hardware (late 2000), mind you. If there is room for improvement I would ...
3
votes
1answer
46 views

How do I forbid access to physical memory in Linux?

I'm on an embedded system (Zynq from Xilinx. It uses ARMv7, Cortex-A9), and running Linux. I need to ensure that no access to a certain physical memory range is ever made, either accidentally by the ...
1
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0answers
20 views

What is kswapd_low_wmark_hit_quickly from /proc/vmstat

What does this parameter mean? # cat /proc/vmstat | grep low kswapd_low_wmark_hit_quickly 2
0
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0answers
13 views

Page Fault Frequency Algorithm - Compute number of frames and mean resident set

I'm reading about Page Fault Frequency algorithm but I don't understand how can I compute the number of frames. For example I have my reference string: 112233444412412214432255543 and control ...
0
votes
1answer
41 views

Substantial portion of memory used is not accounted for by user processes

I recently installed a copy of Ubuntu Server 14.04.2 LTS on a cluster. All appears to be working fine, but a large portion (around half) of our total available RAM is being used. I.e., when I run ...
10
votes
1answer
120 views

Does anyone actually use and benefit from transparent huge pages?

I've been struggling with transparent huge pages performance issues of late, and noticed many database systems recommend turning it off. I am talking Oracle, Postgresql, MySQL, Cassandra, NuoDB, ...
2
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2answers
784 views

How to mount a dd-image which was created via fmem (memory dump tool)

I'm quite new to Linux. I've used the tool fmem for creating a memory dump dd-file. That works fine. But how can I access this image? I've tried it with mount but it says I have to specify a ...
0
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0answers
61 views

How to determine the memory usage of a single process?

There a few helpful scripts out there, which give some useful information. But I would like to calculate those values myself. I am interested in values like USS and PSS. I already had my first attempt ...
3
votes
2answers
54 views

Sum the memory usages of all the processes of a program?

How can we sum the memory usages of all the processes of a program? For example, I have opened many Chrome tabs for webpages, and each tab runs a different process. How can I get the total sum of ...
13
votes
8answers
3k views

Memory problems when compressing and transferring a large number of small files (1TB in total)

I have 5 million files which take up about 1TB of storage space. I need to transfer these files to a third party. What's the best way to do this? I have tried reducing the size using .tar.gz, but ...
0
votes
1answer
109 views

Process Being Killed due to low swap

I'm running a python (2.7) script on mac osx yosemite. The script is fairly computationally intensive, certainly bumping up against my machine's RAM limitations. The computer crashes and restarts ...
1
vote
2answers
30 views

What unit is used for the memory values from top command in Linux?

I have the following snippet shown as my top command output. One real quick question here being, the values of Mem are shown in what granularity? Are they the number of bytes? Mem: 8191488k total, ...
0
votes
2answers
68 views

Linux Mint 64 bit eating ram

I have a Mint 17.1 install. It has 2x2Gb memory sticks. I have verified this with sudo dmidecode --type memory. My problem is that I don't see all the memory I expect.I would expect 4194304 kB. (i.e. ...
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votes
1answer
36 views

Memory utiization

I use free -m to check memory status. In this pic we see total used & memory. I want the result in %. Like Used memory - total memory x by 100. And whenever I want to check the memory status, it ...
1
vote
3answers
344 views

How to calculate the memory consumed by a “C” program in linux

I have written two C programmes one is using function pointer, and the other without function pointer. Now i want to know the memory consumed by the two programmes , to see how memory can ...
1
vote
0answers
177 views

Java process gets killed frequently by OOM - Killer on upgraded hardware

I am running solr on an Ubuntu server along with 4 other java processes. Current index size is 30 GB. My solr process gets killed frequently in few hours. It clearly mentions that its an OOM killer. I ...
7
votes
3answers
446 views

When a process forks is its virtual or resident memory copied?

The standard way of making new processes in Linux is that the memory footprint of (parent) the parent process is copied and that becomes the environment of the child process until execv is called. ...
0
votes
1answer
24 views

/dev/mapper/vg00-var maxing out

Over the past few years we have had multiple Linux servers have the same problem time and time again: our /dev/mapper/vg00-var folder maxes out at 100%, which means all sites on the server die. We ...
1
vote
2answers
49 views

CRON Job To Execute Command On Low Memory

I have a situation where I may need to execute an SAP command line tool hdbsql when memory gets too low (to help clean out the HANA table cache). I'm not well versed in Unix/Linux, and was wondering ...
0
votes
0answers
78 views

Kill the process and restart server when memory is exceeded - bash and cron

I have a site on webfaction, using django and python. However, I have problem with memory. The problem arises, because I use external library, that can run forever (consuming much time and memory). ...
1
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0answers
11 views

How to recover data after memory module errors [duplicate]

My linux PC has suffered the occasional application crash, desktop crash, and kernal panic over the last few months. I also started noticing error dialogs on login, and some parts of the desktop do ...
3
votes
1answer
52 views

Linux doesn't drop FS Caches. Instead Memory starts Swapping

I'm quite confused about this behaviour of linux memory caching. total used free shared buffers cached Mem: 15953 14188 1765 64 ...
1
vote
2answers
537 views

How to enable swap accounting for memory cgroup in Archlinux?

On my Archlinux box I want to limit some applications to a smaller amount of memory using cgroups. Since I use swap, I need to account memory+swap. How can I enable swap accounting?
1
vote
2answers
92 views

What proportion of memory does the Linux kernel use of the installed RAM?

I'm developing a compute cluster and I'm trying to determine the maximum amount of RAM I can give to a single process. On a machine with 16GB of ram, the answer is that I can allocate (and touch) ...
0
votes
1answer
134 views

what does mean by HardwareCorrupted, DirectMap4k, DirectMap2M fields in “/proc/meminfo” file of Linux?

I am looking for description of following terms: HardwareCorrupted, DirectMap4k, DirectMap2M fields in "/proc/meminfo" file of Linux. I could find the following description for the fields from ...
3
votes
4answers
626 views

Memory consumption Fail2Ban CentOS

Fail2Ban is using a huge amount of memory on my system (1.2 GB). There are several articles which describe how to reduce it. Below is an example for Debian. append the 1ulimit1 command to ...
1
vote
1answer
42 views

Who are the Linux Memory “subsystem” developers?

After an hour of googling, I still cannot find Linux Memory subsystem developers contact e-mail. Question: Where is the webpage that shows who develops the Linux kernel, specifically the Memory ...
0
votes
1answer
121 views

git Fatal: Out of memory, malloc failed on branch push

I know this has been asked a lot but I did not manage to get any solution to solve my problem. My coworker assigned me on a new project. The application is hosted on test Debian server with git ...
0
votes
1answer
27 views

What is kernel memory and user memory? (question about the term kernel page and the page cache)

Today, I have read through some documents about file system (http://tekrants.me/2014/07/14/linux-file-system-write/). And the term kernel page is mentioned several times in this article. I am now ...
2
votes
0answers
75 views

How to read the output of the show-memory-usage SysRq?

I couldn’t find any (recent) documentation on reading the output of the show-memory-usage SysRq (Alt+SysRq+m). So what can one learn from looking at it? Here is an example output form my box (Kernel ...
2
votes
2answers
23 views

Utility which gives line from /proc/id/maps by specific address

Is there an utility that gives me specific line from /proc/id/maps when given specific address from this process? For example when given 0x7fb4a84f6008 it returns: 7fb4a84f6000-7fb4a84fd000 r-xp ...