12-17-2011
Quote:
Originally Posted by
joaming
Where does this memory allocation come from? How can I remove it to free up the 959MB ? In what circumstances, this allocation will be used ?
Let me start with a question: Why are you so concerned about 1GB of space? ... Or: why are you so opposed to swap? I think you should read the link dude2cool posted. It looks like it's a good page of info.
In short: You can get rid of the swap space you have, and use it for something else, but it might be a lot of work.
You can get more information on the kernel's currently activated swap space with
swapon -s (which simply shows you the content of /proc/swaps). Make note whether the output says something like "/dev/mapper/vg_apriori-lv_swap" or something like "/dev/sda6" -- you'll need this info later. Look at the man page for swapon/swapoff before using them for anything other than
-s, but basically.. you could do a
swapoff -a to turn off all registered swaps and then remove the appropriate [swap] entry from /etc/fstab, which would then allow you to reclaim that space.
In order to so, you'll either have to delete the swap logical volume (if your swap was on something that started with "/dev/mapper/...") and then extend your root (or home) logical volume ... OR, if you're really unlucky, you'll have to delete the swap partition and boot into something like PartedMagic in order to rearrange your partitions to make use of the freed up space.
Last edited by ryran; 12-20-2011 at 10:04 AM..
This User Gave Thanks to ryran For This Post:
10 More Discussions You Might Find Interesting
1. UNIX for Dummies Questions & Answers
In Solaris 2.6 and 8
How do I find out how much swap and memory is free?
Also how can I see how much memory each process is consuming?
Thanks in advance (2 Replies)
Discussion started by: expos
2 Replies
2. UNIX for Dummies Questions & Answers
I'm interested in adding more swap space to my current workstation (Solaris 10). I currently have 2 hard drives installed, however the system was only created with 512MB for swap that resides on drive 1. This drive is already sliced up and all slices are being used.
The second drive has two... (3 Replies)
Discussion started by: here2learn
3 Replies
3. UNIX for Dummies Questions & Answers
Can somebody explain it to me that why wc gives more chars suppose
Ab.txt have two lines
qwer
qasd
then wc -c ab.txt will give 10.why not 8.okay may be it is taking count one for each line just in case but why echo "qwer"|wc -C gives 5.
Ok with \c it is returning 4. :) (6 Replies)
Discussion started by: Dhruva
6 Replies
4. Solaris
Hi Folks,
This is my first post here - so nice to meet u all :-)
Recently i was trying to dig a little bit into the memory structure of my machine and due to the lack of concept, cannot figure out a calculation.
This is how it goes:
1) My swap slice is at the usual /dev/dsk/c0t1d0s1... (0 Replies)
Discussion started by: s4g3
0 Replies
5. UNIX for Advanced & Expert Users
When i run this command on my linux machine:
mail -s "CVS ALERT-CRITCAL" sandy@xyz.com
The system hangs up producing a dead letter. What should i do to resolve this.
I am using :
mailx -s "CVS ALERT-CRITCAL" sandy@xyz.com
This cammnd works fine on another Linux machine but says"... (14 Replies)
Discussion started by: bsandeep_80
14 Replies
6. UNIX for Dummies Questions & Answers
Hi
I have checked the output of top command in which there is a difference shown between the swap of top command for a process with total swap memory usage of the top command.
Swap usage of process is higher than the total swap memory usage.
top - 18:28:21 up 7:13, 5 users, load... (2 Replies)
Discussion started by: gagan2914
2 Replies
7. UNIX for Advanced & Expert Users
Hi,
Please help explain and answer the below:
1. I need to predetermine how much swap will my JVM use if it is started with -Xms 512M and -Xmx 1024M ?
2. Can a JVM process just use the Heap and not the Swap memory ?
3. If the Total physical RAM on my server is 8 GB and current Heap... (6 Replies)
Discussion started by: mohtashims
6 Replies
8. Shell Programming and Scripting
Its rather confusing, the output of top command is below:
The "swap" field of top is described by the manpage as: "The swapped out portion of a task's total virtual memory image."
But the output of free command suggests something else and it does tally with the output of swapon... (3 Replies)
Discussion started by: proactiveaditya
3 Replies
9. Programming
Hello,
This is very silly question as millions discussions on call-by-value vs call-by-reference for programming beginners, but I need to confirm my understanding.
#include<stdio.h>
void swap(int *p, int *q) //Line 3
{
int tmp;
tmp = *p;
*p = *q;
*q = tmp;
}
int... (15 Replies)
Discussion started by: yifangt
15 Replies
10. Solaris
I have a Solaris 10 VM that processes are seg faulting on (no space) and swap goes from 64GB to 151MB which triggers the seg fault. The free memory is 25GB when this occurs. I have adjusted the project to use all available ram. My question is why is swap being filled with 25GB remaining?
the... (10 Replies)
Discussion started by: thefroggy
10 Replies
SWAPON(8) Linux Programmer's Manual SWAPON(8)
NAME
swapon, swapoff - enable/disable devices and files for paging and swapping
SYNOPSIS
Get info:
swapon -s [-h] [-V]
Enable/disable:
swapon [-f] [-p priority] [-v] specialfile...
swapoff [-v] specialfile...
Enable/disable all:
swapon -a [-e] [-f] [-v]
swapoff -a [-v]
DESCRIPTION
swapon is used to specify devices on which paging and swapping are to take place.
The device or file used is given by the specialfile parameter. It may be of the form -L label or -U uuid to indicate a device by label or
uuid.
Calls to swapon normally occur in the system boot scripts making all swap devices available, so that the paging and swapping activity is
interleaved across several devices and files.
swapoff disables swapping on the specified devices and files. When the -a flag is given, swapping is disabled on all known swap devices
and files (as found in /proc/swaps or /etc/fstab).
-a, --all
All devices marked as ``swap'' in /etc/fstab are made available, except for those with the ``noauto'' option. Devices that are
already being used as swap are silently skipped.
-e, --ifexists
Silently skip devices that do not exist.
-f, --fixpgsz
Reinitialize (exec /sbin/mkswap) the swap space if its page size does not match that of the the current running kernel. mkswap(2)
initializes the whole device and does not check for bad blocks.
-h, --help
Provide help.
-L label
Use the partition that has the specified label. (For this, access to /proc/partitions is needed.)
-p, --priority priority
Specify the priority of the swap device. priority is a value between 0 and 32767. Higher numbers indicate higher priority. See
swapon(2) for a full description of swap priorities. Add pri=value to the option field of /etc/fstab for use with swapon -a.
-s, --summary
Display swap usage summary by device. Equivalent to "cat /proc/swaps". Not available before Linux 2.1.25.
-U uuid
Use the partition that has the specified uuid.
-v, --verbose
Be verbose.
-V, --version
Display version.
NOTES
You should not use swapon on a file with holes. Swap over NFS may not work.
swapon automatically detects and rewrites swap space signature with old software suspend data (e.g S1SUSPEND, S2SUSPEND, ...). The problem
is that if we don't do it, then we get data corruption the next time an attempt at unsuspending is made.
swapon may not work correctly when using a swap file with some versions of btrfs. This is due to the swap file implementation in the ker-
nel expecting to be able to write to the file directly, without the assistance of the file system. Since btrfs is a copy-on-write file
system, the file location may not be static and corruption can result. Btrfs actively disallows the use of files on its file systems by
refusing to map the file. This can be seen in the system log as "swapon: swapfile has holes." One possible workaround is to map the file to
a loopback device. This will allow the file system to determine the mapping properly but may come with a performance impact.
SEE ALSO
swapon(2), swapoff(2), fstab(5), init(8), mkswap(8), rc(8), mount(8)
FILES
/dev/sd?? standard paging devices
/etc/fstab ascii filesystem description table
HISTORY
The swapon command appeared in 4.0BSD.
AVAILABILITY
The swapon command is part of the util-linux-ng package and is available from ftp://ftp.kernel.org/pub/linux/utils/util-linux-ng/.
Linux 1.x 25 September 1995 SWAPON(8)