MEM(4) Linux Programmer's Manual MEM(4)NAME
mem, kmem, port - system memory, kernel memory and system ports
DESCRIPTION
mem is a character device file that is an image of the main memory of the computer. It may be used, for example, to examine (and even
patch) the system.
Byte addresses in mem are interpreted as physical memory addresses. References to nonexistent locations cause errors to be returned.
Examining and patching is likely to lead to unexpected results when read-only or write-only bits are present.
It is typically created by:
mknod -m 660 /dev/mem c 1 1
chown root:kmem /dev/mem
The file kmem is the same as mem, except that the kernel virtual memory rather than physical memory is accessed.
It is typically created by:
mknod -m 640 /dev/kmem c 1 2
chown root:kmem /dev/kmem
port is similar to mem, but the I/O ports are accessed.
It is typically created by:
mknod -m 660 /dev/port c 1 4
chown root:mem /dev/port
FILES
/dev/mem
/dev/kmem
/dev/port
SEE ALSO chown(1), mknod(1), ioperm(2)COLOPHON
This page is part of release 3.53 of the Linux man-pages project. A description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
Linux 1992-11-21 MEM(4)
Check Out this Related Man Page
MEM(4) Linux Programmer's Manual MEM(4)NAME
mem, kmem, port - system memory, kernel memory and system ports
DESCRIPTION
mem is a character device file that is an image of the main memory of the computer. It may be used, for example, to examine (and even
patch) the system.
Byte addresses in mem are interpreted as physical memory addresses. References to nonexistent locations cause errors to be returned.
Examining and patching is likely to lead to unexpected results when read-only or write-only bits are present.
It is typically created by:
mknod -m 660 /dev/mem c 1 1
chown root:kmem /dev/mem
The file kmem is the same as mem, except that the kernel virtual memory rather than physical memory is accessed.
It is typically created by:
mknod -m 640 /dev/kmem c 1 2
chown root:kmem /dev/kmem
port is similar to mem, but the I/O ports are accessed.
It is typically created by:
mknod -m 660 /dev/port c 1 4
chown root:mem /dev/port
FILES
/dev/mem
/dev/kmem
/dev/port
SEE ALSO chown(1), mknod(1), ioperm(2)COLOPHON
This page is part of release 3.27 of the Linux man-pages project. A description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
Linux 1992-11-21 MEM(4)
I have a Sun V880/ Solaris 8/ 16 G of memory
We previously had 8 G of mem. Started getting fork errors. Thought problem was becauseit was low on memory. Upgrade to 16 G of mem. Still, box is getting fork errors. Not seem to be using over 7 G of memory. We think it's the PeopleSoft and... (10 Replies)
Hi,
Q1-What does
nroff -ms > /dev/null
Q2- What does mean -A under STAT column :
ps aux |head -20
UTIL PID %CPU %MEM SZ RSS TTY STAT STIME TIME COMMAND
root 516 93,0 0,0 12 12 - A 04 nov 3906:51 wait
Thank you. (4 Replies)
Hi,
how to know size of physical memory under AIX ?
Many thanks.
PS :
man -k memory
man : 0703-310 Fichier man introuvable.
uname -a
AIX server1 1 5 005202DF4C00 (3 Replies)
Hello this is a book problem of chapter 8 william stallings's operating systems..can anyone tells me the accurate solution of it??
The Unix kernel will dynamicaly grow a process's stack in virtual memory as needed, but it willnever try to shrink it. Consider the case in which a program calls a C... (7 Replies)
Hi all,
I'm trying to convert a decimal number into an integer number; I'm doing this:
n=`echo |awk '{ print "'"$mem"'"*10}'`
where the variable mem is equal to 3.7
I'd like to obtain 37, but the expression above gives me 30.
Help please!!!!
thx a lot (4 Replies)
Hello ,
I want to check the file permissions of /dev/kmem .
I am getting 2 kind of file perms...
so which permission i have to consider..
here is 2 case ..
1. ls -al /dev/kmem
lrwxrwxrwx 1 root other 27 Sep 8 2008 /dev/kmem -> ../devices/pseudo/mm@0:kmem
2. ... (4 Replies)
I have a csv file which has three columns
mem no. name surname
1234 John Smith
12345 John Doe
I want to change the mem no. to add TF to the mem no. field i.e.
mem no. name surname
1234TF John Smith
12345TF John Doe
How do you do this for all records in the file? (3 Replies)
I would like to pipe "top -n" to a text file, but I get an error:
top: cannot open /dev/kmem
kvm_open: Permission denied
I am a non-root user.
If I could find a way to get this type of output:
"Memory: 2048M real, 1516M free, 4099M swap free"
into a text file, I could further automate... (13 Replies)
Hello all. I need a simple way to write to a specific memory space (/dev/mem). In a bash script if possible. (I am using dd to read the changes) Thanks in advace. (4 Replies)
mknod /dev/vda b 253 0
mknod /dev/vda1 b 253 1
mknod /dev/vda2 b 253 2
mknod /dev/vda3 b 253 3
I know below code is ease to handle, but I don't know above code
mknod /dev/vda1 b 253 1
mknod /dev/vda2 b 253 2
mknod /dev/vda3 b 253 3 (3 Replies)
Hi,
When I run the free command on solaris, I get the following:
"Memory: 60G phys mem, 69G free mem"
Q: how cna the free mem be higher then the physical mem?:confused:
Amit (3 Replies)
I am trying to understand how people manage lifecycle patching these days. I am not a sysadmin (I am a DB Architect) and what I am being told is that if there is any lag between patching a dev server and a prod server that we will liley get new patches in prod that have not had any soak time in... (9 Replies)
Can anyone here help me in understanding how to patch AIX machine.Its all vulnerability patching and i have sent an attachment with this saying what needs to be patched.I have not done patching at all.Can anyone help me with the steps on how to do the Patching.Whoever is helping i think this is... (3 Replies)