Swap space is an area of the hard disk that serves as an overflow when the computer memory is full. The memory used by inactive applications is partially written out to disk to make room for other applications and for the disk cache for active files.

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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 ...
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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?
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How to make files inside TMPFS more likely to swap

I'm using tmpfs for my /tmp directory. How can I make the computer decide to swap out the files inside the /tmp before swapping out anything that is being used by applications? Basically the files ...
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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 ...
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Why is my swap not being activated automatically via fstab?

I've got a Linux embedded system that I'm experimenting with (the Elektor Embedded Linux Made Easy board, based on the GNUBLIN http://en.gnublin.org/index.php/GNUBLIN-Elektor). I'm using the 3.3 ...
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Swap partition in LVM?

I was wondering if putting the swap partition into a logical volume group has any drawbacks (e.g. performance), or would it be "just the same" as having it as a separate primary/logical partition? I ...
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25 views

Extending swap on Centos

I recently created a swap file on my centos 6 based VPS using this guide. Now I wanted to extend this swap and I was reading through this guide. However, I think I've created a swap file than a ...
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27 views

Sanity check/cleanup for swap — essentially mkfs.swap

Occasionally I'll have a system crash or be forced to do a cold reboot. Upon rebooting I will get a kernel crash. Get out a rescue disk, rebuild swap, then everything boots fine. The thing is that I ...
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KVM and Swap space

suppose the following scenario: a host with 2 GiB runs a few guests using KVM. Each guest does usually not need much memory, they are given 256 MiB each and run services that mostly twiddle their ...
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Allocation of Swap in 64 bit UBUNTU 13.04

I have 256GB ssd drive, 32GB DDR RAM, and 1TB HDD. What is the maximum limit of Swap memory that can be set in SSD?
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Swap on video ram in a VM

I have a very small VM running in a cloud with only 512 MB ram. I read, it is possible to use the video card as swap as descriped here: Graphics cards contain a lot of very fast RAM, typically ...
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Out of Swap - What happens?

On my debian VM machine with 512MB RAM and 348MB Swap, what will happen if i open a 1GB file in an editor and get out of memory? Will it crash the system? Or if not, how will linux handle this? ...
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Does asynchronous disk IO affect swap usage?

I have a server application requiring usage of huge memory but can take little time. I therefore thought it should be economical to run it with a big swap and normal ram. I was reading about serving ...
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Xeon Phi swap from host's tmpfs

I want to use swap on Xeon Phi (mic0) using RAM from the host On the host: # free -m total used free shared buffers cached Mem: 129022 60312 ...
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Dynamically growing swap file on Debian

I know how to create a swap file and use it as swap. But I have to configure the size of the file beforehand and the space is used on the disk, if the swap is used or not. How do I create a swap that ...
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76 views

When is swap triggered or how to calculate swap_tendency?

I'm trying to use Redis for production services and trying to avoiding swapping, which is bad for performance. I had learn that swap is triggered by swap_tendency which is depending on ...
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33 views

Is zswap eligible to reduce swap IO?

Does zswap compress pages, that are written to the swap device? Is it eligible to reduce swap IO?
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49 views

Swap not mounting

I have just installed SolydX (Debian based) onto a laptop with the following specs: -Toshiba Tecra A4 -800MHz Centrino CPU -nVidia 6600 GPU -512MB RAM After installing Conky to monitor my system, I ...
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Can swap be encrypted per user?

The problem arises for a multiuser computer with encrypted swap, as to how to allow each user to hibernate and resume from hibernation without compromising the security of the other users. I'm ...
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Tool to force use FILE instead of RAM

I'm wondering why there is no such tool like ram2swap, similar to cpulimit in parts. E.g. There is program daemon.bin. Let's create temporary swap file ( 1 Gb ): % dd if=/dev/zero of=tmp.swap ...
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71 views

Increasing swap space without reinstallation

I'm running Fedora 20, and I forgot to change my swap size allocation during installation. I have 16G of RAM, so I'd like to allocate 32G of swap space. The install created a swap for me, of only ...
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376 views

what does “Read Swap Header failed: Success” mean?

I'm trying to install Arch Linux (from the 2014-04-01 snapshot). I've made a swap file and tried to swapon it, but I got an error(?) message I don't understand. I've executed fallocate -l 512M ...
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Can swap be shared safely while hibernating?

Suppose I have two different Linux installations A and B, both using the same swap partition. As I understand, running A or B will cause no problems with swap as only one of them is using it at a ...
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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 ...
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Does changing of the swappiness need a reboot?

If I configure the swappiness value to another, from ex.: 60 to 0, then I always need to reboot the machine to the changes to take effect? Even when modifying with: sysctl -w vm.swappiness=0
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What does it mean exactly when a processes “Time” has stopped in top?

I'll be looking into why we're getting critical swap alerts, and I'll find something like: PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ SWAP COMMAND 14683 user1 30 10 16.0g 772m ...
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How to ask for a password to mount crypted swap at boot time on Linux Mint 16 with initramfs-tools? [duplicate]

I use encrypted home folders on my notebook, which prevents use of hibernation on standard setup, because - and for a good reason - besides encrypting the home folder with ecryptfs, it reformats the ...
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Is there a way to prevent SWAP from collecting cached data?

Here is the following info: Do I need more swap? No, disk caching only borrows the ram that applications don't currently want. It will not use swap. If applications want more memory, they ...
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220 views

swappiness and RAM usage

Been going through this topic - http://askubuntu.com/questions/157793/why-is-swap-being-used-even-though-i-have-plenty-of-free-ram. Turned down swappiness to 10 and then to 0 but my installation is ...
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547 views

Log from oom killer

I'm running a virtual machine at a provider where you pay for everything you use (CPU, memory, disk IO, bandwidth, etc). Currently my machine has 512MB ram and 1GB swap area. The kernel version is ...
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332 views

How to recover from a boot hang after deleting old swap?

I did a fresh installation of Fedora 20 in the free space of my hard drive after failing to upgrade from the older version. Everything seems to be working fine until I deleted the partition containing ...
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182 views

How much swap space should I use? [closed]

What rules should I follow to determine how much swap space my linux-based computer should have today?
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429 views

How to change swap partition from primary to logical?

I was installing Mint on dual boot with Win8 and I accidentally created primary swap partition. Is there any way I can change the partition type from primary to logical? Or do I have to delete those ...
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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 ...
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Is swapping the cause of high IO on my box?

I'm running a LAMP stack on an Amazon EC2 micro instance with 616 MB of memory. This seems sufficient to be able to run a few small websites with Apache, MySQL and PHP. I have one Wordpress site ...
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How can my HDD swap without a swap partition?

I have no swap partition on my disk because I prefer having the OOM reaper kill anything it wants quickly rather than having to wait 10 minutes for my swap partition to get filled + 5 other minutes to ...
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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 ...
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111 views

How can I tell how much my system is swapping?

Is there a good way to see how much my system (for example how frequently, how much swap space it is using each time/ on average) is using the swap space during various tasks?
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52 views

Can a VM swap to host main memory.?

While my developer machine has a lot of memory, my vmware VM is 32 bit only and needs some swap space. Can I make it to swap into the host memory? If so, is it possible to use compressed swap space ...
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How to migrate files on Linux from HDD to SSD on a VDS

I upgraded my Dedicated Server and I was having problems finding my SSD. I found out how to MOUNT my SSD. I now have my 100 GB HDD and now 20 GB HDD. [root@server /]# mount /dev/xvdb1 /ssd ...
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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 ...
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GNU/Linux swapping blocks system

I have used GNU/Linux on systems from 4 MB RAM to 512 GB RAM. When they start swapping, most of the time you can still log in and kill off the offending process - you just have to be 100-1000 times ...
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Something happened to Swap; it is not used by default

I always have to go to gparted and then turn my swap on. The swap space isn't used by default and if I turn the swap on, the swap is not used! How can I make the swap space be used by default at boot? ...
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Zswap, Zram, Zcache desktop usage scenarios

I've been trying to understand the difference in use cases for Zswap, Zram, and Zcache. Apologies in advance for the long/slightly sloppily worded question. I've done a bunch of googling, and I ...
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Copy of full swap file is empty

I use a swap file (/mnt/swap). The swap works right. I need to get an access to the data stored in. When it's full of data in some part (which I can see typing "free" in terminal), I copy the file to ...
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How to get data shown out of workspace or directly from application?

Because of some reason I had to use another web browser than my main which I use daily and I chose a small browser which I installed long time ago. This brower is called Dooble, version 0.07 ...
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187 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 ...
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Process Monitoring on Solaris

$ prstat -t NPROC USERNAME SWAP RSS MEMORY TIME CPU 164 oracle 5446M 5445M 8.3% 13:47:50 1.6% 52 root 576M 728M 1.1% 42:29:50 1.0% 1 noaccess 300M 273M 0.4% 0:20:54 0.0% ...
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Could the Kernel stack of a process be empty, when a process is swapped out to a disk?

I am just curious to know whether the Kernel stack could be empty when a process is swapped out to a disk or not?
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Can Linux “run out of RAM”?

I saw several posts around the web of people apparently complaining about a hosted VPS unexpectedly killing processes because they used too much RAM. How is this possible? I thought all modern OS' ...