Hy, I've an 486 dx2 laptop an I want to run unix on it, the problem is it has only 4 megabytes of ram, so my question is; does anybody know an unix based OS which runs with only 4 mb?
thanx (7 Replies)
Hi,
I am seeing very high kernel usage and very high load averages on my system (Although we are not loading much data to our database). Here is the output of top...does anyone know what i should be looking at?
Thanks,
Lorraine
last pid: 13144; load averages: 22.32, 19.81, 16.78 ... (4 Replies)
Hi All,
In my application malloc is returning NULL even though there is sufficient amount of free memory is available but swap memory is low.
Is this possible that, if free memory is high & swap memory is low, malloc will not be able to allocate memory & return NULL ?:)
Kindly look into... (5 Replies)
on the file Ftp'd from the mainframe ,do we have any UNIX command to replace mainframe low and values to space or null.
i tried using tr and it doesn't work ...
Thanks (1 Reply)
Is it possible to have a bash script pick the highest and lowest values of four variables? I've been googling for this but haven't come up with anything. I have a script that assigns variables ($c0, $c1, $c2, and $c3) based on the coretemps from grep/sed statements of sensors. I'd like to also... (5 Replies)
Hi guys,
i have a question about spliting a binary file into 2 chunks.
First chunk with all high bytes and the second one with all low bytes.
What unix tools can i use? And how can this be performed?
I looked in manpages of split and dd but this does not help.
Thanks (2 Replies)
I've got a domain running on a few boards of a 25k. I'm seeing very high kernel cpu usage in top and cant' quite explain it. System runs a large number of smallish Oracle 10g2 databases (30), used mainly for development.
load average: 36.63, 36.68, 37.42
2489 processes: 2452 sleeping, 21... (0 Replies)
Need some clarification on this....
1. how are kernel/ user spaces and high/low memory related?
2. What do they all mean when i have the kernel command line as:
"console=ttyS0,115200 root=/dev/sda2 rw mem=exactmap memmap=1M@0 memmap=96M@1M irqpoll"
or
2. what do mem and memmap mean in... (3 Replies)
Hello All
I have a system running AIX 61 shared uncapped partition (with 11 physical processors, 24 Virtual 72GB of Memory) .
The output from NMON, vmstat show a high run queue (60+) for continous periods of time intervals, but NO paging, relatively low I/o (6000) , CPU % is 40, Low network.... (9 Replies)
Discussion started by: IL-Malti
9 Replies
LEARN ABOUT FREEBSD
md
MD(4) BSD Kernel Interfaces Manual MD(4)NAME
md -- memory disk
SYNOPSIS
device md
DESCRIPTION
The md driver provides support for four kinds of memory backed virtual disks:
malloc Backing store is allocated using malloc(9). Only one malloc-bucket is used, which means that all md devices with malloc backing
must share the malloc-per-bucket-quota. The exact size of this quota varies, in particular with the amount of RAM in the system.
The exact value can be determined with vmstat(8).
preload A file loaded by loader(8) with type 'md_image' is used for backing store. For backwards compatibility the type 'mfs_root' is also
recognized. If the kernel is created with option MD_ROOT the first preloaded image found will become the root file system.
vnode A regular file is used as backing store. This allows for mounting ISO images without the tedious detour over actual physical media.
swap Backing store is allocated from buffer memory. Pages get pushed out to the swap when the system is under memory pressure, otherwise
they stay in the operating memory. Using swap backing is generally preferable over malloc backing.
For more information, please see mdconfig(8).
EXAMPLES
To create a kernel with a ramdisk or MD file system, your kernel config needs the following options:
options MD_ROOT # MD is a potential root device
options MD_ROOT_SIZE=8192 # 8MB ram disk
makeoptions MFS_IMAGE=/h/foo/ARM-MD
options ROOTDEVNAME="ufs:md0"
The image in /h/foo/ARM-MD will be loaded as the initial image each boot. To create the image to use, please follow the steps to create a
file-backed disk found in the mdconfig(8) man page. Other tools will also create these images, such as NanoBSD.
SEE ALSO disklabel(8), fdisk(8), loader(8), mdconfig(8), mdmfs(8), newfs(8), vmstat(8)HISTORY
The md driver first appeared in FreeBSD 4.0 as a cleaner replacement for the MFS functionality previously used in PicoBSD and in the FreeBSD
installation process.
The md driver did a hostile takeover of the vn(4) driver in FreeBSD 5.0.
AUTHORS
The md driver was written by Poul-Henning Kamp <phk@FreeBSD.org>.
BSD October 30, 2007 BSD