09-25-2013
You can force a process to start out mostly in swap, but if the process runs at all it will wind up in RAM. Running something totally from swap is a bad idea, and if allowed, it results in a real performance drag called thrashing. The swapped process runs 100's of time slower and can seriously degrade the whole system. For every other process on the system.
If you got this idea from seeing how much memory a service is using, you may have misunderstood. A lot of the working set of a process is in shared memory. All processes use this shared memory at the same time. If each of the required system processes (services among them) had nothing but private memory, it likely would have eaten most of system memory before you even logged onto a newly booted box.
You may want to rethink this swap idea.
These 2 Users Gave Thanks to jim mcnamara For This Post:
10 More Discussions You Might Find Interesting
1. Filesystems, Disks and Memory
I need to put a program together to determine the total, available memory and total and available swap on unix machines. I have been searching for weeks and I seem to run into dead ends. Every unix platform I look at has a different way to determine memory info.
Any sugggestions or new... (4 Replies)
Discussion started by: ghe1
4 Replies
2. Solaris
Hi
Can any help me on setting the swap memory ? I would like to set swap memory for installing oracle 9i software.
RAM - 512 Mb
HDD - 40 Gb
OS - Sun Solaris 5.9 (6 Replies)
Discussion started by: sivaramat
6 Replies
3. Solaris
Hi all
Got myself in a pickle here, chasing my own tail and am confused. Im trying to work out memory / swap on my solaris 10 server, that Im using zones on.
Server A has 32Gb of raw memory, ZFS across the root /mirror drives.
# prtdiag -v | grep mem = Memory size: 32768 Megabytes
#... (1 Reply)
Discussion started by: sbk1972
1 Replies
4. UNIX for Dummies Questions & Answers
Hi,
I want to see used swap memory
I know that for this there is command free -m
but this shows Swap: 16383 4529 11854
by top command
while load is 1.05
max CPU % 24 mysqld
why used swap shows 4529
either it is not flushed
there is other command... (2 Replies)
Discussion started by: kaushik02018
2 Replies
5. 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
6. UNIX for Dummies Questions & Answers
hi guys
the monitoring team is using a tool for monitoring linux boxes and they set an alarm for swap memory to 10%(critical) I really has no idea when swap memory usage is high....
Can someone recommend me a threshold for this? when is warning or critical and this parameters can affect... (3 Replies)
Discussion started by: karlochacon
3 Replies
7. UNIX for Dummies Questions & Answers
In Linux, Unix environments Is swap and Shared memory the same ?
In Linux, swap is mounted on /dev/shm ? I am wondering if the naming of 'shm' has anything to do with Shared memory ? (3 Replies)
Discussion started by: kraljic
3 Replies
8. HP-UX
here is the output of swapinfo command
==> swapinfo
Kb Kb Kb PCT START/ Kb
TYPE AVAIL USED FREE USED LIMIT RESERVE PRI NAME
dev 8192000 0 8184000 0% 0 - 1 /dev/vg00/swap
reserve - 8184000 -8184000
memory ... (5 Replies)
Discussion started by: mohtashims
5 Replies
9. Linux
Hi,
In our production box i can see the Swap space using the below command
free
total used free shared buffers cached
Mem: 65963232 41041084 24922148 0 877160 35936292
-/+ buffers/cache: 4227632 61735600
Swap: 4192880 ... (6 Replies)
Discussion started by: ratheeshjulk
6 Replies
10. Red Hat
Admins,
How can I configure the server so that it will utilize the swap file as little as possible? Please correct me if I'm wrong, I would say change the value of sysctl - vm.swappiness? And if, how can I keep it permenatly even after rebooting the system? since no related parameters in... (7 Replies)
Discussion started by: leo_ultra_leo
7 Replies
LEARN ABOUT HPUX
services.window
services.window(4) Kernel Interfaces Manual services.window(4)
NAME
services.window - file containing applications and their associated memory window ID
DESCRIPTION
The file is used by applications using memory windows.
Each line in the file associates an application with a memory window ID. A line in the file cannot start with a space or tab. The format
is a unique name, defining the application, followed by a space/tab, followed by a unique window_id. See the sample file in
Memory windows allows for the starting of a process in a unique or existing memory window where it can create and share objects with other
applications in the same memory window.
The creation of memory windows removes the system wide restriction on shared resources. Without memory windows, 32-bit processes were lim-
ited to 1.75 gigabytes of shared resources. Each memory window allows for the definition of a unique 1 gigabyte quadrant and since multi-
ple memory windows can be defined in a system, the system total for shared resources can exceed the 1.75 gigabyte limitation for 32 bit
processes.
The definition of a memory window is only available for 32-bit processes.
The file provides a central place for memory window applications to associate their memory window IDs. In the event there are any colli-
sions, only a change in is necessary to select another memory window for the entire application. If is not used, and user applications
hard code window IDs in their startup scripts, collisions are not easily detected or easily fixed.
A memory window application uses the command getmemwindow(1M) to extract the application's window_id from the file, and then passes that ID
to the setmemwindow(1M).
Using the same window ID places applications in the same memory window.
EXAMPLES
Below is a example of a file.
AUTHOR
was developed by HP.
FILES
File containing applications' associated window ID.
SEE ALSO
getmemwindow(1M), setmemwindow(1M).
on
services.window(4)