Sponsored Content
Full Discussion: swapinfo question
Operating Systems HP-UX swapinfo question Post 87741 by Perderabo on Thursday 27th of October 2005 09:41:13 AM
Old 10-27-2005
Are you saying that this box is at 95% after adding swap? Smilie

1. You cannot use more than 100% of your virtual memory. If you try, some horrible error will occur. At the time this swapinfo was performed, the box was nearly out of virtual memory. Maybe that 1/2 GB left is enough, but if not, the box will be unable to create new processes.

2. Originally Unix required swap area for any virtual object. So you first 6 GB of swap would simply enable the use of your 6GB of physical memory. Any swap after that gives you additional space over the 6GB. Under this scheme, you could in theory swap everything out. You have the kernel parameter swapmem turned on (which is wise). So the kernel pretends that you have an extra swap area which is sized at 4.7 GB. This means that you no longer have enough real swap to completely empty memory. The kernel computes the size of this imaginary swap area as a fixed percentage of the physical memory size.

This box fully consumed physical memory some time ago. This does not affect stability but it can affect performance. To see how bad that is, you want to watch this box's scan rate. (sr in the vmstat display).
 

9 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

Well, im getting it, but i have ONE question

Hay everyone, i would like to take this opportunity to thank all of you who helped me make the decision to get a linux distro. As a newbie, Im defininately considering buying Mandrake Linux... I went to the site and phew..... 2300 applications, i think ill have a good time. But i do have a... (5 Replies)
Discussion started by: LolapaloL
5 Replies

2. UNIX for Dummies Questions & Answers

Vi Question

In Vi, if I have a list of text, and i want to add a semi-colon to the end of each line, does anyone know how to do this? (1 Reply)
Discussion started by: BG_JrAdmin
1 Replies

3. HP-UX

pstat call to get "swapinfo -at"

Hi, The swapinfo -at command gives the below information. TYPE AVAIL USED FREE USED LIMIT RESERVE PRI NAME dev 4194304 0 4194304 0% 0 - 1 /dev/vg00/lvol2 localfs 2048000 0 2048000 0% 2048000 0 1 /data/paging reserve - ... (1 Reply)
Discussion started by: rajeshvadh
1 Replies

4. Shell Programming and Scripting

question

how do i write a script that'll open what i entered and scan it for a certain line of text. for example, i enter a filename (that exists) and in that file i want to scan a certain word that'll show how much of that word appears throughout the file. (2 Replies)
Discussion started by: mrhenry
2 Replies

5. UNIX for Dummies Questions & Answers

Question

I need to write a script file that will tell me the largest number in a group of numbers. ANy help is greatly appreciated (2 Replies)
Discussion started by: twan
2 Replies

6. Shell Programming and Scripting

Help with Swapinfo automation Alert script

I am new to unix scripting (HP-UX) and need to write a script for checking memory usage. I am using "ipcs -ma" and using "awk" to select specific colums and redirecting output to variable. /usr/bin/ipcs -ma | awk '{ print $5,$10,$12}' > $TMP_FILE exec < $TMP_FILE while read line; do ... (1 Reply)
Discussion started by: JamesBond007
1 Replies

7. UNIX for Dummies Questions & Answers

Help me these Question??

1. How the Unix system identify the Other User to access for file permission? 2. What command we use to convert the extension of a file name? 3. What command use to convert other editing file to Unix based text file? Please answer of these Question???Its necessary for me?? (3 Replies)
Discussion started by: pradipta_pks
3 Replies

8. Programming

C++ little question

Hi, I am doing a C++ self-study and I got stuck with this problem. I want to have a code that asks the suer to enter two numbers and then it lists the numbers between these two numbers. It has also to print a message if these two numbers are equal. Here is what I wrote: #include <iostream>... (11 Replies)
Discussion started by: faizlo
11 Replies

9. Shell Programming and Scripting

A question

Hi, I'm new to unix and got struck here.Can any one help me out.My question is .. is the command if ; then echo "do some stuff" fi correct? Thanks in advance abhijeet (18 Replies)
Discussion started by: Abhijeet_Atti
18 Replies
swap(1M)                                                  System Administration Commands                                                  swap(1M)

NAME
swap - swap administrative interface SYNOPSIS
/usr/sbin/swap -a swapname [swaplow] [swaplen] /usr/sbin/swap -d swapname [swaplow] /usr/sbin/swap -l /usr/sbin/swap -s DESCRIPTION
The swap utility provides a method of adding, deleting, and monitoring the system swap areas used by the memory manager. OPTIONS
The following options are supported: -a swapname Add the specified swap area. This option can only be used by the super-user. swapname is the name of the swap file: for example, /dev/dsk/c0t0d0s1 or a regular file. swaplow is the offset in 512-byte blocks into the file where the swap area should begin. swaplen is the desired length of the swap area in 512-byte blocks. The value of swaplen can not be less than 16. For example, if n blocks are specified, then (n-1) blocks would be the actual swap length. swaplen must be at least one page in length. The size of a page of memory can be determined by using the pagesize command. See pagesize(1). Since the first page of a swap file is automatically skipped, and a swap file needs to be at least one page in length, the minimum size should be a multiple of 2 pagesize bytes. The size of a page of memory is machine dependent. swaplow + swaplen must be less than or equal to the size of the swap file. If swaplen is not specified, an area will be added starting at swaplow and extending to the end of the designated file. If neither swaplow nor swaplen are specified, the whole file will be used except for the first page. Swap areas are normally added automatically during system startup by the /sbin/swapadd script. This script adds all swap areas which have been specified in the /etc/vfstab file; for the syntax of these specifications, see vfstab(4). To use an NFS or local file-system swapname, you should first create a file using mkfile(1M). A local file-system swap file can now be added to the running system by just running the swap -a command. For NFS mounted swap files, the server needs to export the file. Do this by performing the following steps: 1. Add the following line to /etc/dfs/dfstab: share -F nfs -o rw=clientname,root=clientname path-to-swap-file 2. Run shareall(1M). 3. Have the client add the following line to /etc/vfstab: server:path-to-swap-file - local-path-to-swap-filenfs --- local-path-to-swap-file -- swap --- 4. Have the client run mount: # mount local-path-to-swap-file 5. The client can then run swap -a to add the swap space: # swap -a local-path-to-swap-file -d swapname Delete the specified swap area. This option can only be used by the super-user. swapname is the name of the swap file: for example, /dev/dsk/c0t0d0s1 or a regular file. swaplow is the offset in 512-byte blocks into the swap area to be deleted. If swaplow is not specified, the area will be deleted starting at the second page. When the command completes, swap blocks can no longer be allocated from this area and all swap blocks previously in use in this swap area have been moved to other swap areas. -l List the status of all the swap areas. The output has five columns: path The path name for the swap area. dev The major/minor device number in decimal if it is a block special device; zeroes otherwise. swaplo The swaplow value for the area in 512-byte blocks. blocks The swaplen value for the area in 512-byte blocks. free The number of 512-byte blocks in this area that are not currently allocated. The list does not include swap space in the form of physical memory because this space is not associated with a particular swap area. If swap -l is run while swapname is in the process of being deleted (by swap -d), the string INDEL will appear in a sixth column of the swap stats. -s Print summary information about total swap space usage and availability: allocated The total amount of swap space in bytes currently allocated for use as backing store. reserved The total amount of swap space in bytes not currently allocated, but claimed by memory mappings for possi- ble future use. used The total amount of swap space in bytes that is either allocated or reserved. available The total swap space in bytes that is currently available for future reservation and allocation. These numbers include swap space from all configured swap areas as listed by the -l option, as well swap space in the form of physical memory. USAGE
On the 32-bit operating system, only the first 2 Gbytes -1 are used for swap devices greater than or equal to 2 Gbytes in size. On the 64-bit operating system, a block device larger than 2 Gbytes can be fully utilized for swap up to 2**63 -1 bytes. ENVIRONMENT VARIABLES
See environ(5) for descriptions of the following environment variables that affect the execution of swap: LC_CTYPE and LC_MESSAGE. ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Availability |SUNWcsu | +-----------------------------+-----------------------------+ SEE ALSO
pagesize(1), mkfile(1M), shareall(1M), getpagesize(3C), vfstab(4), attributes(5), largefile(5) WARNINGS
No check is done to determine if a swap area being added overlaps with an existing file system. SunOS 5.10 20 Jan 2004 swap(1M)
All times are GMT -4. The time now is 01:44 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy