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.
3
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1answer
463 views
Command for swap info in HPUX itanium and HPUX PARISC?
I need to get commands for swap information in HPUX (both Itanium and PARISC) somebody please help.
-1
votes
0answers
29 views
Process of writing to disk [duplicate]
I was asked this question and not sure how to answer. What is the process of writing information to a storage device (Kernel calls, swap, inodes, etc.)? I could not find a good in depth explanation. ...
1
vote
1answer
106 views
Which processes swaps memory
I can see swap's total, used, free etc. sizes from top command.
But I can't figure out which process uses swap, is it possible to find out swap memory by process?
I'm running CentOS 6.3.
1
vote
2answers
63 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
37 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 ...
4
votes
1answer
41 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
65 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 ?
6
votes
2answers
2k views
How can I check if swap is active from the command line?
How can I check if swap is active, and which swap devices are set up, on the command line?
65
votes
7answers
10k views
Why use swap when there is more than enough RAM
Using swap space instead of RAM can drastically slow down a pc.
So why, when I have more than enough RAM available, does my Linux system (Arch) use the swap?
Checkout my conky output below:
...
5
votes
2answers
956 views
What is the appropriate value of vm.swappiness when using zram?
I'm using zram on my computer as a compressed RAM-backed swap. When the system needs to swap something out, swapping it to a zram-backed swap file is more or less equivalent to compressing that data ...
10
votes
4answers
13k views
How to completely disable swap?
I am using Debian sid, hard drive formatted with ext4, running on linux 3.1
I remember on previous linux versions (maybe before 3.0), if I run out of memory, and swap is not enabled, programs will ...
7
votes
3answers
400 views
Why does it makes sense to cache swap?
It sounds quite counter-productive to me to cache pages that are swapped out. If you swap pages in, what is the advantage to first cache them in memory, only to have to than move them to the right ...
8
votes
4answers
3k views
how to “unswap” my desktop
If my desktop run out of memory and swaps a lot then I free or kill the application wasting my RAM. But, after that, all my desktop/applications have been swapped and are horribly slow, do you know a ...
2
votes
0answers
74 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: ...
2
votes
2answers
107 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
70 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 ...
0
votes
3answers
523 views
kswapd0 takes 99% to 100% CPU in RHEL 6.3
I have 5 systems on which I have just installed RHEL6.
System configuration is
CPU-i7
HDD-500 GB
RAM-2 GB
Swap- 4 GB
I have installed the same software's and all the configuration as per old ...
2
votes
1answer
397 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 ...
1
vote
2answers
117 views
Is it a bad idea to not have a swap partition on an embedded linux setup?
I have a small embedded linux kernel and file system created via buildroot that is installed onto a compact flash drive running on an x86 board. I am using an initramfs (due to power loss concerns) ...
0
votes
2answers
97 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 ...
2
votes
2answers
260 views
How do I configure systemd to activate an encrypted swap file?
My previous question produced the commands to add an encrypted swap file:
# One-time setup:
fallocate -l 4G /root/swapfile.crypt
chmod 600 /root/swapfile.crypt
# On every boot:
loop=$(losetup -f)
...
2
votes
2answers
300 views
Does swap need to be on a contiguous LVM logical volume
I am setting up a machine to run a number of virtual machines. I am using a single HDD with a boot partition and an LVM partition. I read on the Arch wiki that logcial volumes which will be used for ...
6
votes
1answer
343 views
How do I set up an encrypted swap file in Linux?
How do I set up an encrypted swap file (not partition) in Linux? Is it even possible? All the guides I've found talk about encrypted swap partitions, but I don't have a swap partition, and I'd ...
22
votes
7answers
893 views
Is swap an anachronism?
I've used unix for quite a while, and for the last couple years I've felt like swap is an anachronism, but I'd be curious what other folks think.
My argument is roughly this (assuming no global ...
3
votes
2answers
197 views
Memory management, bias to swapping
I was having 768 MB RAM. In a general day MySQL was using 100-180 mb of RAM and MySQL was swapping 80-120 mb. I was having 50-60 mb free RAM.
So I thought I should upgrade. Then I upgraded my RAM ...
6
votes
3answers
157 views
How can I open a file in VIM in readonly mode if it already has a swapfile?
When I use the command :e filename to open a file and this file is already opened by another vim instance, I get a prompt asking me if I want to open the file in read-only mode, edit anyway, recover, ...
11
votes
2answers
1k views
How can swapoff be that slow?
Somehow I happened to swap out 14 GB of memory. After having killed the culprit, I have tons of free memory again, so I thought I could bring in the important data again. So with 5 GB out of 32 GB ...
0
votes
2answers
822 views
Create swap partition after install
I already have parititon contain data under lvm enviroment with centos 5.8
output of fdisk -l
root@server [~]# fdisk -l
Disk /dev/sda: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, ...
1
vote
0answers
153 views
Is there an in-memory compressed swap facility (like Compcache) for FreeBSD?
Is there anything like CompCache for FreeBSD?
0
votes
1answer
108 views
What does m represents in VIRT column using TOP command
When we run top command it shows all the processes information. But under VIRT column there is m written against some values what does that m represents, is it MB . If yes then why it is only showing ...
5
votes
3answers
888 views
How can I tweak the kernel for total swap out?
I would like to deploy the following swapping policy:
By default all pages in memory should also be in swap space.
When a page in memory is changed (i.e. dirty), the page should be written out as ...
4
votes
3answers
1k views
Swap usage too high?
I have a debian sid box, freshly installed about a month ago, with no desktop apps running at the moment.
Any command I try to run (via ssh) makes the hard disk work very hard. The system worked ...
2
votes
1answer
486 views
Is it possible to trigger OOM-killer on forced swapping?
Is it possible to have the system preemptively swap out inactive pages (vm.swappiness), but invoke the oom-killer when the system runs out of RAM (as opposed to running out of memory) and is forced to ...
4
votes
2answers
339 views
Linux (3.4) SSD swap partition usage causes extreme latency - how to eliminate?
I'm running on 4G RAM with an extra 6G swap partition, SSD is a pretty decent SAMSUNG MZMPA128HMFU model. System responds very well to workloads when things stay in RAM, but as soon as things reach ...
1
vote
1answer
104 views
Turn on Swap after resize /
I resized with lvresize the swap from 4 to 2G and can't turn it on.
swapon /dev/VolGroup/lv_swap
swapon: /dev/VolGroup/lv_swap: swapon failed: Invalid argument
lvdisplay /dev/VolGroup/lv_swap
...
3
votes
1answer
247 views
How to stop waking all attached drives on reboot / deactivating swap?
A fresh install of Debian 6.0.6 for a system has 13 SATA drives attached. 12 refurbished WD-10EARS drives are yet unpartitioned. 1 WD1500BLFS drive is configured for OS and swap. Swap partition is ...
4
votes
5answers
3k views
What is the use/meaning of 'swap area' while linux installation?
When i installed ubuntu in my x86 machine, I had to configure some memory as 'swap area'.
What is the use of this memory and what is the importance of this memory in linux file systems?
How can I ...
2
votes
0answers
252 views
zram swap instability
I use Mint 13 Maya with mainline kernel 3.6.3 for Ubuntu Quantal on my Asus P53E Notebook.
I use zram swap that comes with the package zram-config.
I've noticed that using it the system to hangs at ...
4
votes
6answers
537 views
What about no swap?
I have a netbook with a very slow (especially on writes) SSD, would it be a good idea to go without swap? The way I see it is that code and unmodified pages will still be swapped (re-read) but I won't ...
0
votes
1answer
563 views
Drop_caches doesn't drop caches?
Sometimes I see my swap file is a bit bigger then usual. I tried sync && echo 3 > /proc/sys/vm/drop_caches to no avail. But when I tried swapoff -a it takes a bit longer but the swap file is ...
3
votes
1answer
597 views
Solaris swap allocation with mlocked shared memory
I'm having a hard time understanding how Solaris 10 x86 swap allocations work in the
presence of mlocked share memory.
I wrote a small program that:
Gets a 1G SHM segment (shmget)
Attaches it to ...
0
votes
0answers
212 views
Swap space not used
I recently installed Debian 6.0.6. Here are the machine's states:
CPU - AMD XP 3000+
RAM - 1 Gig
HDD - IDE 80 Gig
I primarily use this machine for developing toy personal projects. When I run ...
4
votes
1answer
839 views
Tmpfs only with RAM
How to be sure that a tmpfs filesystem can only deal with physical and it's not using a swap partition on disk ?
Since i have a slow HDD and a fast RAM i would like, at least, giving higher priority ...
1
vote
1answer
821 views
Debian hibernate problem PM: Swap header not found
I have Debian 6 2.6.32-5-amd64 on netbook. With pm-utils Sleep works but hibernate fails with error: PM: Swap header not found!. Swap was enabled using ubuntu tutorial after installation - this is ...
4
votes
1answer
324 views
How to configure swap space after system instalation?
I've installed Debian Wheezy and after installation completed, I realized that I forgot to set the swap memory. So now, how can I configure the swap space?
24
votes
12answers
2k views
How can I tweak my Linux desktop to be more responsive?
I have the experience that Linux works fine until the physical memory is exhausted. As soon as swap space is used the performance is severely degraded and the GUI becomes unresponsive.
This problem ...
3
votes
1answer
383 views
What command can be used to force release everything in swap partition back to memory?
What command can be used to force release everything in swap partition back to memory ?
Presume that I have enough memory.
2
votes
1answer
682 views
Why my partitions don't show the right capacity on a 4096 byte physical block hard drive?
After reading a lot about why newer 4096 byte physical block hard drives should be partitioned taking care of alignment (Linux on 4KB-sector disks: Practical advice, What is partition alignment and ...
3
votes
2answers
327 views
Java process, swap (/proc Solaris10) memory highly utilized
How can I analyze high swap memory utilization of Solaris 10 for Java processes?
5
votes
1answer
136 views
Can I accelerate swap by using multiple harddrives?
I still have two old ATA drives (one is only 8GB, one is somewhat defect) and I've been thinking about putting them into my PC and activating swap on them, too. What will be effect of this? Will my ...
