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
2answers
60 views

How to increase the memory used by Java in linux?

I have a program Vuze that is written in Java, which I use to download very large files, and I'm having a problem with it. I need to increase the amount of memory it uses. I've followed the directions ...
3
votes
1answer
358 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 ...
2
votes
3answers
691 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 ...
43
votes
4answers
36k 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 ...
1
vote
1answer
18 views

Memory usage stays high after compilation jobs

I am operating a small Linux VM with 1Gb of RAM. It is a fairly typical LAMP setup which takes about 16% of memory on normal usage I used the box to compile stuff yesterday, the memory went up to 60% ...
7
votes
0answers
11 views

Reserve fixed RAM memory region as a block device ( with a given start physical address)

There have been a lot of questions about RAM Disks and I am aware of ramfs and tmpfs which allow the use of ram as a block device. However my interest is in using a fixed memory address range as a ...
0
votes
0answers
12 views

how to limit dma address to specific range in linux kernel?

I want to limit the dma address the device can access to 0x0100_0000~0x03ff_ffff. But I don't know how to set the dma_mask and coherent_dma_mask. It's easy to set the "dma mask" for a range start ...
2
votes
2answers
243 views

How to compare usage of memory by Window Managers?

I'd like to test a few window managers to see which of them takes less memory and CPU in certain time period (so is better choice for older computers). I'd like to make the tests myself (not to read a ...
1
vote
0answers
25 views

What is being cached?

I have an embedded system with a low amount of memory. The system has allocation issues. Maybe due to fragmentation: Memory allocation issue on NOMMU? The platform is a NOMMU platform and so I suspect ...
1
vote
0answers
10 views

Evaluating uncorrectable ECC errors and fallback methods [migrated]

I run a server which has just experienced an error I've not encountered before. It emitted a few beeps, rebooted, and got stuck at the startup screen (the part where the bios shows its logo and begins ...
2
votes
2answers
51 views

find out the memory allocated for a particular process in ubuntu

Could anyone please tell me how to find out the memory allocated for a particular process in ubuntu?
1
vote
0answers
43 views

Swap appears to not be in use

(I am currently using Ubuntu 14.04 LTS, GNOME environment) tl;dr How can I force more memory swapping (swappiness already at 100)? I have recently been experiencing a lot of system freezes/crashes. ...
0
votes
3answers
54 views

Lots of free memory, but Java won't start (SunOS 5.10)

vmstat gives: swap free 37489684 110178592 Still I have issues, while trying to run Java process with 10g heap: > java -Xmx10g -Xms10g -d64 HelloWorldApp Error occurred during ...
1
vote
1answer
25 views

Reserve memory for a program

Is it at all possible to set aside say 50MB of memory so that in an emergency where something uses all my memory or loads the CPU I could open a terminal, find the offending process, and kill it?
0
votes
1answer
350 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 ...
1
vote
1answer
487 views

Can I use pmap to find out Memory utilization?

I want to measure memory utilization of my Apache Server. Can I use the pmap command and pass all the process IDs of httpd and take that as total utilization? pmap PID1 PID2 .... It seems that pmap ...
1
vote
2answers
894 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
3answers
4k views

How to get free memory on AIX?

How can I see the free memory on an AIX? There is no free -m under it. AIX oslevel: 6100-03-03-0943
2
votes
2answers
42 views

Memory allocation for sparse array in awk

I have searched but didnt reach to any conclusion that when i defined an sparse array does it reserve all the contiguous memory upto maximum index or it allocate the memory at that particular index ...
0
votes
1answer
331 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 ...
9
votes
6answers
3k views

Is there a tool that allows logging of memory usage?

I want to monitor memory usage of a process, and I want this data to be logged. Does such a tool exist?
2
votes
2answers
416 views

Measuring CPU and Memory per user to distribute “cost” of a server

How should I implement approximately correct per-user monitoring on a server? I want a way to split the cost of a server between the users based on their usage. On newer machines (RHEL6) I would use ...
13
votes
4answers
7k 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 ...
1
vote
1answer
267 views

How do you track memory usage in a ksh93 script

We have a number of ksh scripts that run forever (inside a while loop), or at least until a shutdown event is delivered to them. We had a project where these scripts where converted to ksh93 (and ...
0
votes
0answers
30 views

Inexplicable high memory usage (apparently not caused by programs, buffers, cache, or slab cache)

I've got a server that claims 1.7 of its 2 GB of RAM are used, but the combined memory usage of the running processes doesn't come anywhere near that figure: $ free -m total used ...
2
votes
1answer
7k views

How to find Heap memory of a running process? [duplicate]

I would like to know how to find the heap memory of a process that is running in the background. Is there any command that allows such?
2
votes
2answers
1k 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
votes
2answers
48 views

Use/See whole the flash memory space

When we bought a N Giga Byte flash memory, the free space that the OS provide for us, is less than N GigaBytes. For example, for a 2 GB flash memory, total space that we can use, is 1.86 GB. As far ...
0
votes
0answers
18 views

Is there anything in RHEL 6.5 that would affect I/O speed for something <24K vs >24K?

Generally, transactions for my app of setting and getting data internally are measured in a couple of millis. However, over 24K in size, that time can jump to just over 100 millis. Is there anything ...
6
votes
2answers
967 views

Defragging RAM / OOM failure

This question is fairly lengthy, so I'll ask the questions at the top and then go through my method of coming to the questions: Did (Busybox based) rm not execute because there wasn't enough ...
1
vote
1answer
35 views

Fastest and Safest way to increase Swap Space on Scientific Linux

Memory Swap Ratio Company System Today, a monitoring system indicated that one of the systems in the company has run out of memory. Executing htop on this system indicated that the Memory was nearly ...
1
vote
2answers
86 views

Why does Linux only see 3832MB of my 4096MB of RAM?

I am setting up a lot of 64-bit RedHat VMs (VMware vSphere) for our development department in my company. Most of them start with 4096MB of RAM, but Linux only seems to recognize 3832MB. Can anyone ...
-1
votes
1answer
24 views

How to prevent certain memory location to be accessed [duplicate]

I have 2 corrupted RAM module, on offset: 46xx MB and 13xxx MB (from memtest on boot) How to prevent Linux to access/alloc/read/write into those offset? Here's the result of memtester on ~1000 MB to ...
0
votes
1answer
31 views

How can I tell if lack of memory is causing these crashes?

I have a tornado web server running a flask application that connects to a postgres 9.3 database on an ubuntu 12.04 box. The application has been crashing intermittently and I am trying to understand ...
1
vote
1answer
49 views

Real vs Actual memory in Xymon/Hobbit

What is the difference between real and actual memory usage in xymon ?
1
vote
1answer
47 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?
0
votes
2answers
46 views

What are the positions in `free` called?

I am trying to compare the output of free with the output of sar -r: # sar -r 12:00:01 AM kbmemfree kbmemused %memused kbbuffers kbcached kbcommit %commit 12:10:01 AM 629756 65293976 ...
19
votes
3answers
3k views

What does the vm.swappiness parameter really control?

Per the kernel documentation: This control is used to define how aggressive the kernel will swap memory pages. Higher values will increase aggressiveness, lower values decrease the amount of swap. ...
2
votes
4answers
148 views

How much RAM needed for preventing use swap?

At my system always available some "Free" and "Inactive" memory, but sometimes system move couple megabytes to swap. Per night it maybe around 100MB, but for a few days in swap could be more than ...
0
votes
0answers
26 views

Why does Android crash when stressed on Memory where as GNU-Linux keeps running?

I have two devices, an Android phone with an eGlibC stack running side by side with Bionic, and an old HP tower with Debian. My HP tower has 512 MB of RAM. My phone has 2GB of RAM. I run top on ...
3
votes
4answers
115 views

What is using memory? [closed]

According to htop and free, the machine I'm looking at is currently at 6631 / 11907 MB of RAM. That's more or less half of the RAM available. However when I sort top or htop by MEM%, the most memory ...
6
votes
2answers
328 views

How does stack allocation work in Linux?

Does the OS reserve the fixed amount of valid virtual space for stack or something else? Am I able to produce a stack overflow just by using big local variables? I've wrote a small C program to test ...
5
votes
2answers
33 views

How to monitor Memory utilization of the single process?

How to monitor Memory and CPU usage of the single process by program/executable name(not PID);
1
vote
3answers
3k views

kswapd0 takes 99% to 100% CPU in RHEL 6.3

I have 5 systems on which I have just installed RHEL6. System configuration is CPU-i7 HDD-500 GB RAM-2 GB Swap- 4 GB I have installed the same software's and all the configuration as per ...
7
votes
3answers
3k views

Why is the theoretical RAM limit for RHEL 6 128 TB and how is this determined?

I'm studying for RHCSA and am confused by a statement I came across in some training material: There is no practical maximum RAM, as theoretically, you could run 128 TB of RAM on RHEL 6. But ...
4
votes
1answer
97 views

Maximum memory usable by a 32 bit RHEL 6 system

I have installed a 32 bit RHEL OS on a 64 bit system. From the wiki page of PAE: The Linux kernel includes full PAE mode support starting with version 2.3.23, with Linus Torvalds mentioning ...
0
votes
2answers
32 views

How to format the output of free/sar/such commands?

I need to get some specific columns from the output of free command. The way I'm following doesn't seem good, could anyone please suggest me a better way? bash-3.2$ free -gotsi total ...
2
votes
2answers
28 views

centos5 maximum memory setting for all users

I'm using Centos5 for operating server and the machine has limited memory. There are many users using the server and some of them are running programs which use a lot of RAM. When I check the used ...
1
vote
1answer
69 views

How is 32bit Linux virtual memory structured in relation to PCIe Base Address Registers

I'm working on a Linux system (32 bit, 4GB RAM) and found some contradictory information about memory addressing in Linux. Am I right with this: Only virtual memory has the differentiation between ...
0
votes
2answers
107 views

Linux memory usage?

We have 1TB of memory on a server which hosts an SAP application. When the app is running the memory usage shown in top is around 700GB. When the app is stopped the memory usage shown in top comes ...