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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Is there any relationship between memory fragmentation and whether or not swap is enabled on a system?

One of the answers to Do I need swap space if I have more than enough amount of RAM? got me wondering if there is any relationship between memory fragmentation as measured by cat /proc/buddyinfo and ...
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3answers
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Is swapping enabled by default on common operating systems?

As a result of this question, I was a bit confused. After some research I found that swapping is enabled by default on Mac OS X. Swapping was furthermore introduced in Windows 3.0, so I believe it is ...
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0answers
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Installing Mint 17.1 with swap on different drive?

Installing Mint 17.1 Cinnamon, I used the "something else" mode to set the partitions for root and home. But, it only showed sda and I could not find any way to select a different disk! I installed ...
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12answers
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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 ...
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33 views

How to find the swap uuid

I am in the process of setting up a raid. sda was used during the installation and I just copied the partition table of sda to sdb like so: $ sudo sfdisk -dL /dev/sda > partition_table_sda $ sudo ...
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Calculating RAM/Swap Space Requirements [duplicate]

I have been developing a MySQL database that makes some use of BLObs. This has now been transferred on to a virtual machine (VM) in preparation for going fully into the 'cloud'. However some of the ...
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1answer
25 views

How do I know I should turn swappiness down?

I have 5.5 GiB memory, using 2.8 GiB (~50%), but my swap is using 1.9 GiB of 5.6 GiB (~33%). My computer operates okay but is sluggish at times. So is this a high amount of swap usage or completely ...
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Can swapping be disabled on the application level?

I'm currently using thunderbird with gnupg to read encrypted emails. If I understand the swapping behavior correctly, the memory pages containing the decrypted emails might be swapped out and leave ...
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0answers
61 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 ...
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1answer
57 views

how partition for OpenSuSE dual-boot

Currently I'm running Ubuntu 14.10 and have quite a bit of free space on this disc: thufir@doge:~$ thufir@doge:~$ sudo fdisk -l Disk /dev/sda: 465.8 GiB, 500107862016 bytes, 976773168 sectors ...
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2answers
26 views

Delete a swap partition without user interaction

I have a VM with a swap partition on /dev/sda5. The problem is fdisk is interactive so I cannot use it to delete a partition without user interaction. How do I delete the partition in my ...
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50 views

Same Swap Partition in Multi Boot [closed]

I have a Macbook Pro with 256 GB of space and 8GB of RAM. and I want to make a multi boot like: Mac OS X 120 GB Windows 8.1 30 GB Ubuntu 14.04.1 30 GB Debian 7.7 25GB Arch Linux 15 GB COMMON ...
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31 views

ZFS swap vdev space accounting

I am on an OpenSolaris system with ZFS on it. I am trying to determine the exact space usage and/or reserved space for the swap vdev. root@storage:~# zfs list NAME USED AVAIL ...
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1answer
159 views

When does swap start to be used? When does a process get an out of memory error and be killed?

When does swap start to be used? Is it when the memory is fully used? Or when the memory hasn't been fully used? When does a process get an "Out of memory" error and be killed by the kernel? is it ...
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1answer
49 views

Does a Linux server use swap space of an SSH client? [closed]

I currently am SSHing into a Linux server via my mac's terminal program. Afterwards, I run whatever simulations and calculations I need to do. However, I noticed that after I log in, it says on the ...
2
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1answer
54 views

specific swap partitions for multiple debian instances in a single computer

I'm trying to setup a computer with three debian instances (wheezy, jessie and sid), I've created / and swap partitions for each debian instance, during the installation I did specify which swap ...
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0answers
43 views

Detect whether a swap partition is in use by a hibernated system

Is there a way to detect whether a swap partition contains the memory of a hibernated system? More specifically: suppose I have a Linux installation and that I hibernate it. This means that all the ...
2
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1answer
36 views

Why is my computer sluggish after downloading a lot?

When I download a lot of data (e.g. 3GB) in one go, using a program such as Transmission or Wget, progressively during the downloading, and after it has has finished, the computer always seems ...
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1answer
92 views

What is the difference between MAC OS X “Virtual Memory” and Linux/Unix Swap? [duplicate]

I would like to understand the difference of MAC OS X "Virtual Memory" and Linux/Unix Swap. I ask this because I observed that MAC OS X "Virtual Memory" seems to work way more efficient (in desktop ...
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0answers
34 views

unlimited tmpfs

How to have the advantages of tmpfs and not be limited to its small size? I'm thinking of a shell script that runs as a daemon, monitors RAM and adds more swap files in specified folder, when memory ...
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1answer
123 views

OpenBSD runs out of memory, while not using swap space

I'm working with a fresh install of OpenBSD (5.6 amd64). I'm attempting to build Boost libraries, and quite a few compilations are failing with cc1plus running out of memory errors. I've read ...
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1answer
68 views

When the RAM is used up, what will happen?

When I ran ImageMagick's convert to convert and combine image files into a pdf file, it will create 10GB temporary dirs and files in /tmp. I am not sure if it did that all the time, or because my ...
2
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1answer
27 views

Effects of SWAP failure

A team member has created a swapfile on one of our machines which needed more swap. And he created it on a filesystem on SSD. While our servers are not swapping a lot and probably safe to keep the ...
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0answers
14 views

Http taking all swap [closed]

I have a dedicated server running centos&cpanel with 2 GB of ram where I host several websites. All are wordpress + 1 opencart. Every 2 days or so the swap memory get consumed and server load ...
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1answer
149 views

Opening files of size larger than RAM, no swap used.

I found myself asking this question while doing small experiments and reading upon how memory is managed in Linux. I have a 64-bit Centos 6.5 machine with 512M RAM and 1G SWAP. I created a 1GB file ...
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Does the debian setup with lvm also encrypt the swap partition?

I'm planning a fresh debian install on my notebook and want to have full disk encryption. But I mainly hibernate, which is why I want my swap to be encrypted as well. During the graphical expert ...
2
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1answer
161 views

Why does mouse and keyboard freeze when Linux swaps

I have noticed that under Linux, when there is heavy swapping, the mouse cursor freezes, and even CapsLock or Ctrl+Alt+F1 don't work. The system uses the deadline I/O scheduler but this should not ...
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1answer
842 views

Diagnose high swap usage on AIX

Which would be the best approach to diagnose high SWAP usage on an IBM AIX 6.3 machine? I've already tried with lsps -a and lslv. But also I'm looking for a strong scenario, like using topas. Any ...
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0answers
109 views

Why adding swap space is the slowest part of the booting process? [closed]

I can see that adding Swap space is the slowest part of the booting process. Why? I actually have ~4GB for swap and 2GB RAM memory. dione@saturno:~$ dmesg | grep -C 4 swap [ 2.179979] input: ...
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1answer
59 views

Why do I need mkswap if swap space has been created via fdisk?

I created a partition called /dev/sda3 as a swap partition, and changed the ID to 82 (Linux Swap) via fdisk. If this partition was recognized as a swap partition (seen in the output of fdisk -l and ...
0
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1answer
126 views

What's the pros and cons of disabling the swap partition if the RAM is large enough? [duplicate]

My computer has 16GB RAM and 1TB SSD. So I think the swap partition is not needful. What's the pros and cons of disabling the swap partition if the RAM is large enough? Is it recommended to disable ...
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1answer
135 views

Luks Partition Mounting After Removing From fstab

I have 3 encrypted partitions, one for /, one for /home, and one for swap. It seemed silly to me to type in my password 3 times, so I replaced the swap partition with a swap file on the encrypted ...
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286 views

full disk encryption (including swap, possibly plausible deniability as well)

I'm looking for a method to encrypt my laptop including the swap partition. I also read trough older similar questions but mostly the answer included just a what not much of a how. (Currently I'm ...
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1answer
236 views

What happens when a tmpfs is full and no swap space is available?

Let's say I have a setup with 16 GB of physical RAM, A tmpfs of max. 8 GB containing a file with 5 GB and A swap sized 4 GB. If I'd try to, e.g., create a copy of the 5 GB file on the tmpfs, what ...
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117 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. ...
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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 ...
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94 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 ...
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314 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?
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2answers
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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 ...
2
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4answers
952 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 ...
3
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0answers
152 views

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 ...
4
votes
1answer
1k views

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 ...
0
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1answer
663 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 ...
0
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1answer
139 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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131 views

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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115 views

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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2answers
564 views

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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1answer
93 views

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 ...