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

0
votes
2answers
145 views

Is there a way to free memory? [duplicate]

I remember, back from my days with Windows Vista/7, that there was a tool called memclear or memclean that would free some memory by invoking the NT garbage collection API. Probably it cleared cache ...
0
votes
1answer
62 views

How to find hugepage size on system?

I am getting following two different result. which one i should consider for Hugepage? [root@server ~]# getconf PAGESIZE 4096 [root@server ~]# grep -i hugepagesize /proc/meminfo Hugepagesize: ...
2
votes
1answer
820 views

How to find out how much memory lxc container is allowed to consume?

I'm trying to make ansible set InnoDB buffer pool size to some percent of available memory. But ansible_memtotal_mb and free report how much memory the host has. How do I figure out how much memory is ...
0
votes
0answers
23 views

Best small distro for ROM burning of the system for an embedded system

I am building a specific device and I would like to know what Linux based small distribution would be good when I would choose the put-Linux-on-the-ROM route, so, that the system is not possible to ...
1
vote
0answers
20 views

How to check if an application uses my video card memory?

We can check the core, cpu utiliztion, memory etc of a particular process. Can we check if it uses video card too and if it is how much memory it is using?
1
vote
0answers
48 views

How can I profile/benchmark RAM performance?

I would like to know if my memory hardware is a bottleneck of my system performance. I am dealing with really old hardware (late 2000). If there is room for improvement, I would like to upgrade. ...
0
votes
0answers
47 views

how to enable 1MB dma-kmalloc

I'm running a ubuntu 15.10 VM and testing code that will allocate 1MB dma buffers. However, from the /proc/slabinfo, the max that can be allocated is 8K dma-kmalloc-8192 0 0 8192 4 ...
0
votes
1answer
27 views

What is taking up my memory in my Linux virtual machine

I'm trying to debug an application (mongodb) memory usage on a a virtual machine. mongod, is taking 11% of memory. I know this by using top but when I want to see how much of my 7.5GB is free, I ...
1
vote
0answers
23 views

Working my way through dmesg output on a custom 3.5.4 kernel

Having read this thread here: What does the Virtual kernel Memory Layout in dmesg imply? It sounds like 'lowmem' is exclusively meant for kernel-space. [ 0.000000] virtual kernel memory layout: ...
2
votes
2answers
31 views

What tools can I use to diagnose the exact reason for laptop slowness? And how do I use those tools?

I am running Linux Mint 17 on my laptop. When using applications (mainly Web Browsers) the machine freezes for little time periods. The CPU indicates 100% usage at such times, but this only seems to ...
3
votes
0answers
276 views

Boot rescue kernel at high memory address using kexec on arm

Summary: Crashkernel boots at 512MB address in RAM with kexec -e/-l but not with kexec -p - why? Embedded platform with Marvell Armada XP (MV78460) (ARMv7 with 4 cores) and 1GB of RAM. production ...
2
votes
0answers
311 views

Is unreclaimable memory allocated to slab considered used or available cache?

After evaluating /proc/meminfo, I see the following information: $cat /proc/meminfo MemTotal: 197852592 kB MemFree: 64755992 kB MemAvailable: 65655112 kB Buffers: 4388 kB ...
0
votes
0answers
78 views

Where is my memory being used?

Only 28G is being used by buff/cache. $free -h total used free shared buff/cache available Mem: 188G 87G 72G 17M 28G ...
3
votes
1answer
166 views

How do you prevent system from freezing when memory is used up?

I've been running a process (gdb) that can easily use up all my ram and swap space. Every time that happens the whole system becomes very non-responsive and Xorg will barely update, I can't swith to ...
3
votes
1answer
230 views

How to run free command by crontab

I want to run this command: free && sync && echo 3 > /proc/sys/vm/drop_caches && free -m by cron. That way I can free my RAM and cache in an Ubuntu system. I'm using ...
0
votes
1answer
49 views

How do I check how much total memory my VM has? [closed]

I've tried /proc/meminfo but my permission has been denied.
3
votes
1answer
202 views

What is the usual Allocation unit for a process on Linux?

I'm currently studying memory management in Operating Systems. Allocation Unit is the smallest unit of memory the OS will give to any process. I've read in this page, in the 'Memory allocation ...
2
votes
0answers
56 views

What does it mean when a private VM page is none of `rwx`?

UPDATE: It's a padding: every such non-rwx area is preceded with a readable and/or writable area and together they constitute a 64Mb segment (for 64bit architecture). A relevant question on SO: http:...
0
votes
1answer
3k views

find: cannot fork: Cannot allocate memory

I want to delete 1 file at a time from my directory which contains so many files,So i want to remove 1 file at a time. Just to avoid too many reads and failed at too many arguments. find ./Backup/...
3
votes
1answer
86 views

Shared memory v/s physical memory

I have a C++ process which is using shared memory to store and transfer data between its child processes. I want to check the shared memory usage while the parent process is executing just like top ...
2
votes
1answer
288 views

How can two identical virtual addresses point to different physical addresses?

Following a fork() call in Linux, two processes (one being a child of the other) will share allocated heap memory. These allocated pages are marked COW (copy-on-write) and will remain shared until ...
0
votes
1answer
64 views

difference between inactive and free memory in output of FreeBSD top utility?

top -d1 displays following SDRAM usage statistics on one of my older machines: 125M Active, 42M Inact, 51M Wired, 17M Cache, 34M Buf, 2720K Free In total, there is 256MiB of memory installed. ...
0
votes
1answer
73 views

Finding memory corruption bugs in Linux and FreeBSD

In windows, we can enable page heap verification using gflags to catch memory corruption bugs more easily. Is there a similar service/program for Linux and FreeBSD operating systems?
38
votes
4answers
33k 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?
4
votes
2answers
2k views

Restricting memory area for linux kernel

I am running ltib Linux on P1022RDK (P1022 Core) platform. I have 512 MB = 0x20000000 memory. I want my Linux kernel to use the second half of the board memory (i.e from 256 MB to 512 MB) and want the ...
0
votes
1answer
50 views

Hardware specs for Linux machine for cluster administration [closed]

I have just started as cluster system administrator and was asked to choose some features to get bought a personal machine to work on, and most intensive calculations will be perform in the cluster. I ...
2
votes
2answers
782 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 ...
2
votes
3answers
3k views

How to monitor use of Huge Pages per process

I'm trying to determine which process is using a large number of Huge Pages, but I can't find a simple Linux command (like top) to view the Huge Page usage. The best I could find was $ cat /sys/...
1
vote
0answers
35 views

Debian - Memory usage [closed]

I all, I'd like to understand what happens in this system. Running top I get: KiB Mem: 496948 total, 460012 used, 36936 free, 68604 buffers and in the process list the process that ...
1
vote
1answer
1k views

What happens after a page fault?

When a page fault occurs in a Linux system, the interrupt-handler has to figure out the reason why the page fault happened. But how ? Is there anywhere a special number for that !? If yes, where is ...
1
vote
1answer
113 views

How to read .vma files?

I am trying to read a .vma file but no luck finding an application to do it on Linux.. I tried to google it but it didn't work out.. The file was produced by Volatility on Ubuntu Linux 12.04 using ...
3
votes
0answers
94 views

Memory consumption over variable period of time

There are a number of questions on this StackExchange about memory consumption, notably: How to check which process is using most memory How to display top results sorted by memory usage in real ...
3
votes
3answers
2k 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 ...
2
votes
0answers
263 views

Portable way to parse /proc/meminfo

I'm having trouble finding a generic code that work, here, for both CentOS 5/6 and CentOS 7 versions pc the /proc/meminfo file. I Want to compute the "Real Used memory" like free does. (amounts ...
0
votes
0answers
169 views

Dump XEN guest memory image

I am new into memory forensics thing and I am trying to dump a memory image from a XEN guest (Ubuntu 12.04 x64 - domU) in order to analyze it on dom0 (Ubuntu server 12.04 x64) with volatility . For ...
1
vote
0answers
2k views

Bash session errors on commands: “fork: Cannot allocate memory”

I have a bash session open to a remote server and something is wrong. I created a directory "test" and touched the files inside touch 1 2 3 4 5. I then tried to copy the directory cp test/ test2/ and ...
0
votes
1answer
109 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 202:65087584:...
1
vote
1answer
53 views

Cached Memory but swap is being used [duplicate]

I've got a VM with 16gb of memory and recently it's been using some of the swap space. At first I thought this was because it was using all the memory but then I read some articles about the Cached ...
2
votes
1answer
52 views

Is there a brief way to view the top resource usage(CPU, memory or even bandwidth) of a program after its running?

I know I can use top to view the overall real-time CPU & Memory usage, and nload for overall real-time bandwidth usage. But I wish to view the maximum(or average) CPU, Memory, & bandwidth ...
4
votes
1answer
284 views

Shared library mappings in /proc/pid/maps

Why does /proc/pid/maps contain a few records for the same library ? Here is an example: 7fae7db9f000-7fae7dc8f000 r-xp 00000000 08:05 536861 /usr/lib/x86_64-linux-gnu/libstdc++....
1
vote
0answers
36 views

Constant 60KB Shared library memory on /proc/<pid>/maps [duplicate]

In a quest for understanding RAM requirements of system processes, I arrived to analysis of /proc/pid/maps. I have noticed a pattern: many shared libraries have exactly 60KB space allocated in their ...
5
votes
2answers
992 views

Fastest `uniq` tool in linux

I have large text file (1.5 G), I want to know what the fastest and more reliable tool in linux is. I usualy use: awk '!x[$0]++' file.txt But when I use htop command I see my memory usage is ...
1
vote
1answer
25 views

upstart jobs - privileged vs unprivileged

On one of my VMs, some upstart jobs were failing, and when I checked df, showed that I had run out of disk-space (Use% was 100 on /dev/sda1). What I did not get is: the jobs which were running with ...
2
votes
1answer
72 views

Why is IO so high when almost out of memory

On my work laptop with an SSD and no swap, I sometimes run out of memory when running RAM-expensive applications (virtual machine, etc). When that happens, the system becomes slow (expected) but what ...
1
vote
1answer
240 views

Memory usage of a given process (using Linux proc filesystem)

I want to know which files from /proc directory and which fields of these files I need to calculate the memory usage of a given pid. I've been using the "stat" file and the "vsize" parameter that is ...
2
votes
3answers
600 views

Does Linux have ways to cache IO with memory

My server has a large amount of memory. However, the amount of IO (each of which is small) is very high. Is there a way to make a virtual drive out of portion of the memory? I realize I can also use ...
6
votes
1answer
5k views

Mathematical connection between SZ RSS and VSZ in ps o/p?

I wanted to know what mathematical connection is there between the SZ, RSS and VSZ output in ps output e.g. ps -p 2363 -o sz,rss,vsz
5
votes
4answers
235 views

How do see the memory used by a program in ubuntu?

How can I see the raw memory data used by an application ? Like , suppose I have a file name something.sh . Now I run the command ./something.sh , and then I want see all the data its accessing in ram ...
0
votes
0answers
19 views

How to troubleshoot High VIRT and RES memory on a Standby Server

We currently run TIBCO EMS on our RHEL6 servers, it is Active-Passive setup, for some reason we are seeing a really high VIRT and RES usage by the standby instance (approx 198GB). The application (...
1
vote
1answer
30 views

tstime and memory usage

So I am interested in measuring the high-water memory usage of a process. I would love to be able to use tstime but am having troubles figuring it out. Does it work in Unix? When I go to https://...