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.

learn more… | top users | synonyms (1)

3
votes
2answers
59 views

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 ...
1
vote
1answer
17 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 ...
6
votes
1answer
249 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 ...
2
votes
2answers
72 views

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 ...
1
vote
1answer
71 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 ...
1
vote
2answers
311 views

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
2
votes
1answer
18 views

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 ...
1
vote
0answers
16 views

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 ...
0
votes
1answer
33 views

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 ...
0
votes
1answer
83 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 ...
1
vote
1answer
222 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 ...
0
votes
1answer
128 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 ...
0
votes
3answers
86 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?
1
vote
1answer
122 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 ...
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 ...
0
votes
0answers
61 views

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 ...
5
votes
2answers
131 views

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 ...
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 ...
6
votes
1answer
96 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?
2
votes
1answer
40 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 ...
0
votes
1answer
67 views

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 ...
1
vote
2answers
173 views

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 ...
2
votes
1answer
86 views

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 ...
0
votes
1answer
61 views

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? ...
7
votes
1answer
968 views

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 ...
1
vote
1answer
67 views

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 ...
0
votes
3answers
82 views

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 ...
4
votes
1answer
111 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 ...
1
vote
1answer
639 views

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% ...
0
votes
1answer
68 views

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?
10
votes
6answers
1k views

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' ...
4
votes
2answers
212 views

Copying large file causes excessive swap

On a mid-class CentOS 6.4/64 server with 32 GB RAM, 3 TB free disk space, operating as KVM hypervisor, I start copying a 200 GB file to a destination in the same local filesystem. In fact, this file ...
2
votes
2answers
73 views

Swap separation for multiple distributions [duplicate]

I have 3 Linux distributions on my machine (Ubuntu, Arch and Fedora). I allocated half the RAM size (3GB) as swap for each of them. (I have realized that having 3 distributions is not of much use to ...
0
votes
0answers
117 views

swap space allocation vs swaptotal

I created a Red Hat 9 virtual machine on VMware Workstion 9 by allocated the physical memory of 256MB. See pic. When installing Linux, I created the swap partition with a size of 256MB. See ...
2
votes
2answers
443 views

swapoff fails when overcommit_memory==2

I've disabled memory overcommitting by setting overcommit_memory=2. Now when I tried to swapoff, I get this error: swapoff: /dev/sda5: swapoff failed: Cannot allocate memory But I in fact have 0 ...
13
votes
2answers
3k views

Why is swappiness set to 60 by default?

I just read some stuff about swappiness on Linux. I don't understand why the default is set to 60. According to me this parameter should be set to 10 in order to reduce swap. Swap is on my hard ...
0
votes
0answers
136 views

slow Matlab on Ubuntu LTS and ZERO Swap

I was using Matlab2012 under Win7 and my algorithm was consuming a huge amount of memory though it was fast (80 seconds for one iteration). Now I am using Matlab2013 under Ubuntu 12.04 LTS and though ...
9
votes
3answers
706 views

What is the purpose of multiple swap files

During installation of most (if not all) distro's of linux, the hard drive is partitioned to include a swap partition by default. It is possible to change this behavior with swapon -p priority ...
3
votes
2answers
370 views

Does the order of partitions matter much?

I've just ran a test install of Arch on a separate computer, and now I'm ready to do the real thing on my main one. However, since the guide didn't explicitly recommend it, I did not install with a ...
0
votes
0answers
145 views

43 seconds to mount swap on /dev/mapper/cryptswap1

My Linux Mint takes longer than I would expect it to boot. Checking dmesg I see the following consecutive entries: [ 8.335668] Adding 9767484k swap on /dev/mapper/cryptswap1. Priority:-1 ...
43
votes
2answers
2k views

What NOT to put on an SSD?

I bought an SSD and I am going to set up my desktop system with a completely fresh Linux installation. SSDs are known to be fast, but they have a disadvantage: The number of writes (per block?) is ...
1
vote
2answers
443 views

Can linux systems on multiple virtual machines share the same swap partition? [duplicate]

I'm trying to save some disk space between multiple systems and re-using the same swap partition (which seems to be fine). I'm now getting into multiple virtual machines and am thinking of a ...
2
votes
1answer
161 views

Can I remount as readonly if there's a swap image in use?

When am playing with my Android phone (CyanogenMod 10.1 with kernel 3.0.78), I found this: A script in /etc/init.d/99system.swap.sh It remount /system as rw, and creates an image file in ...
5
votes
1answer
121 views

can initramfs be paged out to swap disk?

I am using initramfs to boot Centos via PXE. The initramfs used memory is listed within the "cached" value in /proc/meminfo or via free. Since I need to calculate performance data, I need to know ...
1
vote
2answers
256 views

RAM size and SWAP size

I want to know why the swap partition have to more double size the RAM Size ? for example if the ram installed in machine 64 G.B , the swap have to be 128 G.B ?
14
votes
2answers
637 views

Linux: Total swap used = swap used by processes +?

So, I'm trying to do some investigation on where does swap use come from in a system with high swap usage: # free total used free shared buffers cached Mem: ...
3
votes
2answers
225 views

Where is the virtual memory stored on hard drive?

If a process wants to access a memory address that is not in physical memory, the OS outsources a page frame from physical memory to the hard drive for later use. Where on the hard drive is this data ...
0
votes
1answer
121 views

Arch installation and swap partition

to install Arch on a PC I have to make partition of the HDD boot swap / The swap is used by virtual memory, right? What's up if I make a too small or a too big swap partition? Could I have as ...
2
votes
1answer
473 views

Dual-booting Windows 7 and Mint 14 with “something else” option

I would like to do a dual boot of Windows 7 and Mint 14 on my Acer netbook which already has Windows 7 Pro 64-bit installed on an 1 TB hard drive. I have already shrunk the Windows 7 partition to ...
0
votes
2answers
275 views

swap partition and its laws

I remember for choice of swap partition, we should use (swap > 2xRAM) at least.Of course it deprecated , because max of computer's ram is very high. kernel support it. My question: i remember each ...