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.
2
votes
0answers
64 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
99 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
62 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
366 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
91 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 ...
1
vote
2answers
106 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
3answers
406 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
2answers
217 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)
...
6
votes
1answer
272 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 ...
3
votes
2answers
170 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 ...
1
vote
1answer
93 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.
6
votes
3answers
138 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, ...
0
votes
2answers
645 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, ...
0
votes
1answer
86 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 ...
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 ...
4
votes
2answers
305 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
99 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
...
2
votes
2answers
240 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 ...
3
votes
1answer
238 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 ...
2
votes
0answers
242 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
462 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
490 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 ...
0
votes
0answers
202 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
753 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 ...
4
votes
1answer
267 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?
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 ...
3
votes
1answer
332 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
610 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 ...
5
votes
1answer
134 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 ...
1
vote
1answer
762 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 ...
2
votes
1answer
207 views
Can't add swap file on solaris
I'm trying to add a swap file on Solaris 10. I have already created a 2GB file swap.file. Then, I add a swap file with the command:
swap -a /swap.file
which shows an error:
/swap.file: size is ...
0
votes
4answers
324 views
How to disable swap file after install or during Kubuntu install?
My computer has more than 64KB of RAM (8GB), if I run out of memory I want things to crash so I know I'm out of RAM so I'll buy some instead of say wandering why my computer is running slowly when I ...
4
votes
2answers
484 views
Linux running slow with 0 swap left
Our Linux server is responding very slowly. top doesn't show any excessive CPU usage. I noticed that even though there's about 5GB of free memory, the system is using all of swap with no free swap ...
2
votes
4answers
739 views
How to reduce size of swap after a system is already installed?
I'm running Debian Squeeze 6.0.5. Does the use of swap memory make my computer run slower? If so, how can I reduce the size of the swap memory after the system is already installed?
1
vote
2answers
1k views
free / top difference. Does free show virtual memory?
free -m shows me the following in my system:
total used free shared buffers cached
Mem: 3954 3842 111 0 248 2585
-/+ ...
2
votes
1answer
460 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 ...
1
vote
1answer
131 views
Swap Utilization Increase with Oracle Coherence
We are using Oracle Coherence on linux servers. However, we noticed that because of Coherence processes running, often our swap utilization % increases too much, sometimes becoming more than 98%, even ...
2
votes
1answer
372 views
KVM and swap problem
So I have a problem, I'm managing a server and the swap partition is way too small at the moment. The machine runs KVM with about 24 VM's on it. The problem is that some of them are rather inactive so ...
5
votes
2answers
880 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 ...
20
votes
7answers
850 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 ...
2
votes
1answer
394 views
tmpfs and vm.swappiness
I have started tuning a bit Linux VM performance on my system (yes. I know that vm.swappiness=0 will kill kittens but I found 30-40 as much better for me as it improved my latency - probably at cost ...
7
votes
1answer
922 views
What does the vm.swappiness parameter really contol?
Per the kernel documentation:
This control is used to define how aggressive the kernel will swap
memory pages. Higher values will increase agressiveness, lower values
decrease the amount of swap.
...
3
votes
2answers
312 views
Java process, swap (/proc Solaris10) memory highly utilized
How can I analyze high swap memory utilization of Solaris 10 for Java processes?
0
votes
1answer
289 views
LinuxMint, unable to set swap partitions to equal priority
I only recently realised that you can specify multiple swap partition, spreading them across drives. Well that's great for me as my desktop system often uses swap space and I have three different ...
0
votes
1answer
566 views
Zram does not start at start-up
I am using pinguyos 11.10. Pinguyos is a variant of Ubuntu 11.10.
I have installed zram like this:
sudo add-apt-repository ppa:shnatsel/zram
sudo apt-get update
sudo apt-get install zramswap-enabler
...
10
votes
4answers
12k 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 ...
1
vote
0answers
140 views
Is there an in-memory compressed swap facility (like Compcache) for FreeBSD?
Is there anything like CompCache for FreeBSD?
3
votes
1answer
428 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. Thanks
1
vote
1answer
1k views
How to re-enable hibernate in Kubuntu 11.10?
After making some changes to my swap space, namely deleting and recreating swap space, my Kubuntu 11.10 has lost hibernate functionality. Although the button has returned, hibernating only appears to ...
5
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?
