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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2
votes
3answers
203 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? ...
-1
votes
0answers
20 views

What exactly is a “SWAP FILE” when dealing with RAM in a Linux machine? [duplicate]

What is a swap file and what does it do? How do it increase the RAM and are there any downsides? Why use swap file vs. getting more RAM? Does swap file hurt the CPU IOPS? I understand that it some how ...
2
votes
2answers
67 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 ...
-1
votes
1answer
47 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 ...
0
votes
0answers
27 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
25 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
-3
votes
1answer
61 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 ...
2
votes
0answers
72 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 ...
1
vote
2answers
65 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
38 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. ...
0
votes
3answers
311 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 ...
0
votes
1answer
46 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 ...
2
votes
1answer
123 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 ...
1
vote
1answer
114 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 ...
3
votes
2answers
128 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
70 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
256 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
54 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
125 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
91 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 ...
7
votes
2answers
3k 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
2answers
973 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 ...
0
votes
1answer
88 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?
7
votes
1answer
408 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 ...
0
votes
2answers
189 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 ...
4
votes
2answers
2k 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 ...
1
vote
0answers
166 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 ...
0
votes
0answers
35 views

apache server has weird behavior

Okay, this one's weird for me. I have a wordpress mu site under a dedicated server. It runs Apache 2.2.21 and php 5.3.10. When msn and google bots crawls my site the system crashes. The system crashes ...
-6
votes
1answer
64 views

Am I having too much swap? [closed]

Am I having too much swap space if my server is a 8GB physical ram and I would like to set my swap to 16GB. I am planning to use this server for shared hosting would like know.
1
vote
0answers
121 views

Why is /proc/meminfo reporting misleading SwapTotal

Consider this: [skrat@apex geri]$ cat /proc/meminfo | grep SwapTotal SwapTotal: 18438120 kB [skrat@apex geri]$ swapon -s Filename Type Size Used ...
0
votes
2answers
154 views

How do I resize full root or swap partitions in RAID?

It all began a couple weeks ago: When I try to use vi I get "E297: Write error in swap file $ echo "test" > test produces -bash: echo: write error: No space left on device My bash history is ...
0
votes
1answer
123 views

Should I create a 8 GB swap file on my amazon image?

I have an Amazon image with 1 root image, 1 image that I uses for websites and is only using 25%, and 1 image "unused" So I thought... maybe I can use that unused image for a linux swap file. Since ...
1
vote
3answers
351 views

What is the danger in having a fully used SWAP in an Ubuntu server?

One of my Ubuntu servers' swap partition is full. What are the dangers and/or performance ramifications of this situation?
1
vote
1answer
167 views

Server crash when creating a swapfile on a running machine (CentOS Linux)

I created a swap file with root on a running server, using swapfile creation guides which I found on the net (http://blog.serverbuddies.com/adding-additional-swap-space-to-your-linux-server/m Create ...
1
vote
1answer
297 views

e2fsck on a low-memory machine: can I get more out of scratch_files or swap?

I am running CentOS 6 on a 32-bit machine with 1 GB of RAM. I have a 1TB external HDD that I am trying to run e2fsck on. It runs for about an hour and a half and then fails with Error storing ...
-1
votes
2answers
124 views

Server with high consumption of physical memory; swap is not being used [duplicate]

Please, I need a help. I have a Linux that has the following scenario of RAM memory consumption: root@cpro15623 [~]# free -m total used free shared buffers cached ...
1
vote
1answer
1k views

How much space is in a Solaris /tmp filesystem?

On Solaris, the /tmp filesystem is a filesystem of type "tmpfs". It's implemented in the kernel by allocated space from the virtual memory pool. That means allocation interacts with the available RAM ...
1
vote
1answer
257 views

CentOS webserver memory overflow - cannot log in

Few days ago, my CentOS 6.2 webserver with ISPconfig 3 went down to the extent I wan't able to log in via SSH nor using a console. The console was full of messages "out of memory, killing process, ...
3
votes
1answer
1k views

Why does host swap out VMs when there are 16GB of buffer cache and swappiness = 0? [duplicate]

I have a desktop running Ubuntu Quantal using OpenStack Folsom on an Intel i5 with 32 GB RAM and 2 GB swap. I'm running 7 VMs each sized like a EC2 m1.small, so 1.7 GB RAM each. I'm using KVM. As I ...
2
votes
2answers
276 views

Linux process swap usage is greater than the overall system swap usage

I have a strange problem that when I run top command it shows that some processes are using around 1.5GB of swap space but then the overall usage of the system swap is way to less to something around ...
1
vote
0answers
220 views

Couchbase RAM Usage & Clear cache

I am in a company that is a fan of Couchbase ( Version 1.8.x). Our Couchbase servers always has RAM around 48 GB. Couchbase Total Allocated is 39 GB. Couchbase In Use around ~ 15-29GB . Note ...
2
votes
1answer
74 views

Is there a way to free swap?

After using vmware player with some virtual machine, it seems like my swap stays quite occupied and it doesn't changes unless i reboot it. However, regularly swap is not used much by other ...
1
vote
2answers
294 views

Ubuntu: forcing processes into swap, or into RAM

I am now solving the following problem on Ubuntu: Is it possible to specify if one process should run only in the RAM (i.e. is not allowed to swap) or reversely only in the swap part? I mean that the ...
12
votes
3answers
4k views

How to disable swap files in ESXi?

We are running a few Solaris / Linux VMs on ESXi that contain very sensitive encrypted data that eventually get decrypted as required in memory. Everything is fine, except for the ESXi swap files ...
1
vote
1answer
202 views

How to instruct linux not to swap out hot pages of mmaped files?

I have a server where I run worker processes that mmap serveral rather big read-only "dictionary" files (~8GB total). Tests showed that they actively access only around ~1GB worth of the pages in ...
0
votes
1answer
68 views

Swap files in Cloud Infrastructures

At our company we set up an OpenStack Cloud and are currently creating internal guidelines for creation of OS templates / images. One controversial topic was if we should provide swap inside the VM ...
1
vote
0answers
118 views

Limiting memory usage and mimimizing swap thrashing on Unix / Linux

I have a few machines that I machine that I use for running large numbers of jobs where I try to limit the number of jobs so as not to exceed the available RAM of the machine. Occasionally I ...
0
votes
1answer
812 views

How much RAM do I need to run a forum using Nginx, Gunicorn, Django?

I started an ec2 instance (micro) to test the amount of memory I have available to run a website but I was expecting having a bit more. So my question would be: How much RAM do I need to run a site ...
1
vote
2answers
113 views

How can I determine the method of this DDoS attack? [duplicate]

My server went down earlier - looks like a DDoS. A spike in traffic to around 13mbit, the swap goes from idle to maxed in about 5 minutes, and server stops responding. I would like to protect ...
0
votes
1answer
95 views

how do OS deal with dirty page if there is no swap space [closed]

As in text books OS will move dirty pages to swap space based on LRU algorithm and make space for new process in RAM. But how do OS do this if there is no swap.