Linux divides its physical RAM (random access memory) into chucks of memory called pages. Swapping is the process whereby a page of memory is copied to the preconfigured space on the hard disk, called swap space, to free up that page of memory. The combined sizes of the physical memory(RAM) and the ...

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1answer
18 views

How do I increase the swap size on a xen guest machine using xm?

I'm attempting to increase the amount of swap on a xen guest machine. At first I thought it'd be similar to increasing the hard drive space, which I do like this: cd /srv/xen/domains/$host/ xm ...
1
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1answer
24 views

Swap 99% but regular memory fine

I have a 1GB VPS server. I setup 1GB of swap ram too a few weeks ago and quite often it's hitting 99% whilst the regular memory is usually 40% - 60%. Most of my sites on the server run fine and fast. ...
0
votes
1answer
30 views

how to swap VM disks in azure?

I've have recreated a virtual machine in azure, when I did it azure assigned an OS disk to the VM which is normal and obvious, and I have a disk from my previous virtual machine. for now I got two ...
1
vote
1answer
80 views

Ubuntu Server 14.04LTS Swappiness for server with 16GB memory

(don't worry I'm not asking what my setting should be, asking for the theory behind some conflicting advice I've read) My application is one that is lightweight and not under much load, but needs to ...
0
votes
1answer
60 views

Run app only in swap [closed]

I've a very low priority level program who consume large of memory. I need to free RAM for other programs. My objective is to kill -STOP <pid> this process and ```kill -CONT when i need it. But ...
-1
votes
1answer
42 views

Swapfile on SSD and Memory Speed Comparison [closed]

I'm running Ubuntu on Digitalocean's instance that using ssd as their disk, and I'm using swapfile to help memory does the job. What I wanna know is, how can we compare speed between ram and the ...
1
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0answers
46 views

Why is my server using swap even though there is lots of RAM available? [duplicate]

My server has 24 cores, 16 GB RAM, and 8 SSDs on raid 0 (I think). I've noticed it is now using a low of swap space, even though there is plenty of RAM available. load average: 2.70, 2.54, 2.50 Mem: ...
0
votes
1answer
89 views

How to enable swap with salt stack?

How can I create and enable permanent 1GB swap file with salt stack that will work after reboot? salt.states.mount.swap does not allow to define swap size. Furthermore I need to define swappiness. ...
4
votes
1answer
5k views

How to free swap without rebooting (to avoid hourly alert emails)?

I get alert emails whenever swap usage is at 100%. In my case, swap usage doesn't reduce later on (even though memory is free) so I get an alert email every hour. How can I reduce swap usage without ...
10
votes
11answers
10k views

Linux server is only using 60% of memory, then swapping

I've got a Linux server that's running our bacula backup system. The machine is grinding like mad because it's going heavy in to swap. The problem is, it's only using 60% of its physical memory! ...
5
votes
1answer
265 views

BIND 9.10 constantly killed on FreeBSD 10.0 with out of swap space

In one of our slave DNS servers BIND, version bind910-9.10.0P2_3, constantly get killed with the following message in /var/log/messages: Jul 30 01:00:10 cinnabar kernel: pid 602 (named), uid 53, was ...
0
votes
2answers
96 views

plenty of ram but still swapping

this is graph of my server ram you can see in graph that every time I restart mysqld, swap becomes zero. But increases over time. If i put innodb buffer pool in large size swap rises faster and if I ...
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votes
3answers
1k views

How to increase swap space on a live server

On Ubuntu 14.04, the swap file has to be increased as the memory and swap usage are reaching 100% usage. On a live production server, can the swap be increased with minimal disruption to the service? ...
7
votes
2answers
3k views

How can I create a swap partition on Amazon EC2 with ephemeral storage?

This is the output of df -k: Filesystem 1K-blocks Used Available Use% Mounted on /dev/xvda1 10317860 7059008 2734732 73% / none 847584 0 ...
2
votes
2answers
143 views

Swap memory exhausting server even site has small visitors

I have CentOs 6.5 running on a 32bit VPS host. It is running only php-fpm, nginx, and mysql. I have a site that gets on average 20 visitors per day, but I am recently getting this message from my ...
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votes
1answer
2k views

puppet logical conditions- “onlyif” and “unless” not working

I have written the following code and this works fine if swap is not in place, but once swap is created and if the script is executed again, it leads to error. I tried adding conditions using onlyif ...
2
votes
6answers
4k views

What and why is my swap space used under linux

on my linux system I get these stats from top: Tasks: 155 total, 1 running, 153 sleeping, 0 stopped, 1 zombie Cpu(s): 1.5%us, 0.3%sy, 0.0%ni, 97.4%id, 0.7%wa, 0.0%hi, 0.0%si, 0.0%st Mem: ...
0
votes
0answers
136 views

swapoff running forever on LVM volume

I'm currently trying to resize my swapspace on a Proxmox VE server with LVM volumes, as I'm running out of space for LVM snapshots and the swapspace is fairly oversized: root@rb-srv-gus:~# free -m ...
0
votes
1answer
104 views

lvresize: command not found - RedHat

No search results on google for this. So i am really confused now. I am trying to increase the swap space and lvresize says command not found. Please Help !! using RedHat 64bit
0
votes
3answers
922 views

Is there any reason to NOT have a swap file on CentOS (DigitalOcean)

I'm running a site on DigitalOcean with CentOS 6.5. As has been noted elsewhere, DigitalOcean servers are by default configured without any sort of swap, and I'm wondering if I should add one. I ...
6
votes
3answers
20k views

How do I tell what process is causing kswapd to be in use?

I see kswapd using 100% CPU... how can I tell on which process's behalf kswapd is being used so much?
5
votes
2answers
3k views

Ubuntu Server hanging on adding swap

A fresh install of Ubuntu Server is refusing to boot and hanging on "Adding 524284k swap on /dev/mapper/test--vg-swap_1. Priority:-1 extents:1 across:524284k I can get around this by dropping onto ...
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votes
1answer
118 views

Improve LAMP performance Ubuntu 12.0.4 [closed]

cpu 1.3% mem 476/490MB swap 347/511mb tasks: 43, 29 thr; 1 running load average: 0.10 0.08 0.06 via htop:<br> /usr/sbin/apache2 -k start (listed 8x @ 8.1% mem each) /usr/sbin/mysqld (listed ...
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vote
2answers
1k views

memory leak? RHEL 5.5. RSS show ok, almost no free memory left, swap used heavily

i encounter a very instresting problem, and it seems that some physical may disapper quietly. i am very puzzled, so if anyone could give some help, I would be very appreciated. here is my top show: ...
2
votes
0answers
164 views

Linux (Debian 7 x64) swapping activity despite lots of free memory

Yes, I have reduced vm.swappiness a lot: % sysctl -a | grep swap vm.swappiness = 1 Memory is mostly free: % cat /proc/meminfo | head MemTotal: 8070592 kB MemFree: 2619580 kB ...
35
votes
9answers
10k views

Linux: how to explicitly unswap everything possible?

I've launched something that took lots of memory and now everything lags a lot. I guess all applications' memory has gone to swap in order to free some space for the memory-intensive process, and now ...
1
vote
2answers
67 views

Why is my server swapping at all?

Munin shows ram that is doing nothing most of the time. But swapping still happens. Quite regularly actually, bogging down the hdd. Or am I seeing the ram graph in the wrong way? How would I go ...
-1
votes
3answers
99 views

Linux makes cache for swap. what for?

It looks like joke: swapfile on "ramdysk" in 64bits system? I look into file: /proc/meminfo and made some investigation. Look for line: SwapCached: nnnnn kB . One is what I don't understand. ...
2
votes
1answer
178 views

My Ubuntu VPS is not using available swap, even if OOM. What to do?

I recently added 1 GB of swap to my Ubuntu virtual private server to prevent MySQL crashes on RAM overloading. I followed this tutorial. I use htop to monitor resources. When I use loadimpact to test ...
9
votes
10answers
6k views

How big should the swap partition be?

for some years, I've read that it's a good idea to create a swap partition having the double space of my RAM. does it still apply today? or this isn't needed anymore? I have a server with 8 GiB of ...
0
votes
1answer
76 views

Debian 6 - Linux 2.6.32-5-amd64 - Samba server with 32GB swap - how should i reuse it?

today i have the mission to tuning a Debian samba file server, previously i never ever touched it. RAM = 16GB SWAP = 32GB first of i ran a parted -l and a free -h and i saw one 3TB hdd: /dev/sda ...
8
votes
3answers
3k views

How to create a randomly keyed, encrypted swap partition, referring to it “by-uuid”, on Debian?

It is sensible that if you have any sort of block device encryption implemented on your GNU/Linux system, to encrypt your swap partition too, as any decrypted data may be written in cleartext at any ...
1
vote
1answer
241 views

Server failure in minutes due to high httpd-apache use (attack or bug)

In the last week suddenly I get errors for my server. I try to access my website I get 503 errors. When I check top and other things I see these: 60-65 httpd (apache) processes. (Normally I have ...
4
votes
2answers
293 views

How to read `top`. Process list says processes have swap but overview says no swap is being used

I am using top to monitor my server. The swap row reads Swap: 1044220k total, 0k used, 1044220k free, 148544k cached I have hit O p to sort by swap. PID USER PR NI VIRT RES ...
3
votes
2answers
206 views

How can I keep important VMs in memory without disabling swap?

VM Host -> Xenon E5-2440 w/ 48G mem... Everything runs CentOS6.5 (2.6.32-431) I have 4 guest VMs running each w/ 2G of memory. Their disk images are local files. The host machine is also running a ...
0
votes
1answer
100 views

OpenVZ vSwap Host Configuration

I wish to allocate vSwap memory to my OpenVZ containers. Where does OpenVz get the vSwap memory from? If the host were to run out of physical RAM, would the host start to use its own normal swap ...
0
votes
2answers
606 views

KVM under CentOS, swap exhausted, physical memory available

I've had a test CentOS KVM host running for about a week now with 3 CentOS guests. There's 12GB physical RAM with about 7.5GB actually allocated to VMs. These VMs aren't even being used yet as the ...
0
votes
2answers
63 views

Linux swap, linear write/read

i'm puzzled if linux writes and reads on swap sequentially . Now i'm analizyng pressure on swap partition and it's strange that utilisation is near 90% (util column in iostat ) but throughput is ...
0
votes
1answer
232 views

Why the system information message when accessing an Ubuntu server doesn't match free -m?

Each time I SSH into my AWS Ubuntu servers I see a system information message, showing load, memory usage and packages available to install, like this: Welcome to Ubuntu 12.04.3 LTS (GNU/Linux ...
0
votes
1answer
131 views

Transfer used ram to swap and free more physical ram

I have a vps with 256m physical ram and 512m swap space, I am trying to use a software that need more than 256m and less than 512m ram, so it uses swap. The problem is at some moment of the ...
8
votes
2answers
6k views

How to find what is using linux swap or what is in the swap?

I have virtual linux (Fedora 17) server with 28GB RAM and 2GB swap. The server is running mysql db that is set up to use most of the RAM. After some time running the server starts to use swap to swap ...
3
votes
5answers
1k views

How to prevent going to SWAP?

We have a critical application which uses pretty much of our RAM memory. At most time the application stays in RAM, however there are some situation (e.g. when some other applications and deamons ...
3
votes
3answers
7k views
0
votes
4answers
3k views

Server super slow, RAM & Swap 100% used, ClamAV problem?

My Ubuntu 10.04 server is down since this morning. When I restart it, I can use it for a couple of minutes then the RAM and Swap get full, and SSH doesn't answer. It seems ClamAV is part of the ...
0
votes
1answer
98 views

SWAP reducing SSD write speed?

My SolusVM graphs have been showing 8Gb Swap usage even though the RAM is never over 50% used. Is it possible that virtual machines going into swap will reduce the IO of the SSD?
4
votes
1answer
8k views

why is kswapd using high CPU on an idle system?

I have an idle Linux centOS system and yet kswapd is using 100% cpu. All I have running is a single bash session with top running.... I have 32G RAM and yet kswapd is constantly using 100% cpu for ...
8
votes
1answer
693 views

Background discard on swap partitions on Linux + SSD

Problem I want to enable background TRIM operations on a swap partition within a SSD disk on Linux. According to several articles, e.g. this one, the kernel detects this configuration and ...
5
votes
3answers
5k views

Running out of swap space on web servers, what to do?

I have 2 LAMP web servers that are routinely running out of swap space (see attached top screenshot). Apache's settings are as follows: <IfModule prefork.c> StartServers 64 ...
0
votes
2answers
343 views

Moving a process to and from swap [closed]

I've got serveral processes (game servers) on my linux server that use up 50MB of RAM. They are not constantly being used, and I'd like to be able to run more instances than my RAM capacity allows. I ...
1
vote
0answers
208 views

Is there ever a reason to use tmpfs instead of or in addition to zRAM?

I'm thinking about using zRam on my server. From what I've read about zRam, it apparently does everything tmpfs does and more. Once zRAM is working, is there any reason to keep tmpfs around? Is there ...