Above is the output of 'free -m' from my linux machine. I did some searching on the internet and some of the articles point that linux is memory hungry ( not that it use up memory very fast, but it will use what is available). In my case, what is the free RAM i have? 46M or 518M. I highly do not think that its 46M + 518M.
The used and free Mem adds up to 1010 ( 963 + 46)
I am quite buffled by the -/+ buffers/cache value, the used and free values also adds up to 1010.
so linux is telling me it has used up 963MB of ram and 46MB is still available but on the other hand, it has 491 used in the buffer and 518 in the buffer is free... *confused and curious*
My total physical ram is 1GB. Would appreciate if anyone can explain and 'de-mysterifiy' me.
when /var directory of my machine gets filled up (85%) i removed some old logs. but after cleaning df -k command still shows that /var is still 85% full.
It can detect the actual disk space only after I restart the machine. Is there a way to force df to reflect actual free space without... (1 Reply)
Hi All,
I have a pair of sun ultra 5_10 with SunOS 5.5.1.
Both are almost equally patched and set up with simillar applications.
host# uname -a
SunOS host 5.5.1 Generic_103640-24 sun4u sparc SUNW,Ultra-5_10
Even though both have
same amount of RAM ( 512 Mb ) ,
... (1 Reply)
What's the best way to find out how much memory is being used/available? I tried using free, but I didn't quite understand the output. Can someone explain it?
$ free
total used free shared buffers cached
Mem: 16304536 16256376 48160 0 ... (6 Replies)
I am trying to write a small (and rather simple) script to gather some info about the system and piping it to dzen2
first, i want to explain some things.
I know i could have used conky, but my intention was to expand my knowledge of bash, pipes and redirections inside a script, and to have fun... (14 Replies)
how can I find cpu usage memory usage swap usage and
I want to know CPU usage above X% and contiue Y times and memory usage above X % and contiue Y times
my final destination is monitor process
logical volume usage above X % and number of Logical voluage above
can I not to... (3 Replies)
Hi all,
I'm running a simulator and I'm noticing an slow increase in memory for long simulations such that the simulation has to end because of a lack of memory. A colleague of mine ran Valgrind memcheck and reported that nothing of interest was reported other than known mem leaks. My advisor... (2 Replies)
I recently started working with Linux and wrote my first device driver for a hardware chip controlled by a host CPU running Linux 2.6.x kernel.
1. The user space process makes an IOCTL call with pointer to a user memory buffer.
2. The kernel device driver in the big switch-case of IOCTL,... (1 Reply)
hi , I have a problem about getgroups usage on linux. getgroups can get supplementary groups of a process but if i run a process with root account and I want to get supplementary groups of nobody then what i should do to realize that. (4 Replies)
Hi,
I'm looking into doing a few performance tweaks by adjusting my max memory on a few lpars.
I would to create a time stamp script so i could review it for a week and determine how much space i can lower my max memory to so i could reclaim and allocate that memory to where it is needed the... (2 Replies)
Discussion started by: vpundit
2 Replies
LEARN ABOUT BSD
ram
RAM(4) Kernel Interfaces Manual RAM(4)NAME
ram - ram disk driver
SYNOPSIS
/sys/conf/SYSTEM:
NRAM ram_size # RAM disk size (512-byte blocks)
major device number(s):
block: 3
minor device encoding:
must be zero (0)
DESCRIPTION
The ram pseudo-device provides a very fast extended memory store. It's use is intended for file systems like /tmp and applications which
need to access a reasonably large amount of data quickly.
The amount of memory dedicated to the ram device is controlled by the NRAM definition in units of 512-byte blocks. This is also patchable
in the system binary through the variable ram_size (though a patched system would have to be rebooted before any change took effect; see
adb(1)). This makes it easy to test the effects of different ram disk sizes on system performance. It's important to note that any space
given to the ram device is permanently allocated at system boot time. Dedicating too much memory can adversely affect system performance
by forcing the system to swap heavily as in a memory poor environment.
The block file accesses the ram disk via the system's buffering mechanism through a buffer sharing arrangement with the buffer cache. It
may be read and written without regard to physical disk records. There is no `raw' interface since no speed advantage is gained by such an
interface with the ram disk.
DISK SUPPORT
The ram driver does not support pseudo-disks (partitions). The special files refer to the entire `drive' as a single sequentially
addressed file.
A typical use for the ram disk would be to mount /tmp on it. Note that if this arrangement is recorded in /etc/fstab then /etc/rc will
have to be modified slightly to do a mkfs(8) on the ram disk before the standard file system checks are done.
FILES
/dev/ram block file
/dev/MAKEDEV script to create special files
/dev/MAKEDEV.local script to localize special files
SEE ALSO hk(4), ra(4), rl(4), rk(4), rp(4), rx(4), si(4), xp(4)dtab(5), autoconfig(8)DIAGNOSTICS
ram: no space. There is not enough memory to allocate the space needed by the ram disk. The ram disk is disabled. Any attempts to access
it will return an error.
ram: not allocated. No memory was allocated to the ram disk and an attempt was made to open it. Either not enough memory was available at
boot time or the kernel variable ram_size was set to zero.
BUGS
The ram driver is only available under 2.11BSD.
3rd Berkeley Distribution Januray 27, 1996 RAM(4)