01-19-2019
Note that some systems actively try to use otherwise unused memory to speed up running processes. For example, if a process starts reading from a large file, the system might read the next few blocks (or megabytes) of that file into a system buffer so the data will be in memory without having to wait for the disk to rotate if that process reads the next block.
If other processes start up need the memory that was used for read-ahead buffers they can be reallocated to the next process without affecting how fast the new process can be loaded.
Different versions of BSD, Linux, and UNIX systems use different algorithms to try to make efficient use of memory. And, different releases of each of those systems may change the algorithms as the vendors think they have learned something from past experiences.
In other words, there can be lots of "free" memory may be used to hold data that may soon be useful to someone even though it can be re-allocated immediately if someone asks for it to be put to a specific use.
These 2 Users Gave Thanks to Don Cragun For This Post:
10 More Discussions You Might Find Interesting
1. Solaris
Hi All,
I am trying to find the physical memory usage by each process/users.
Can you please let me know how to get the memory usage?.
Thanks,
bsraj. (12 Replies)
Discussion started by: bsrajirs
12 Replies
2. UNIX for Dummies Questions & Answers
Hi Guys,
How can i check the RAM usage for a particular user on the Linux machine.
What command can be used.
Thanks in advance,
Swapna (1 Reply)
Discussion started by: Swapna173
1 Replies
3. Shell Programming and Scripting
Hi i just wanted to know what is the code to display amount of RAM and also the percentage used? I know i can possibly use the vmstat code but what part indicates the RAM? Any help would be much appreciated. Thanks (1 Reply)
Discussion started by: warlock129
1 Replies
4. Linux
Hi
one of our applications that runs on our Linux server leaks memory resulting in Ram that was used by the program not being released back to the operating system once a file has been processed. the result is over a very short period virtual all the memory has been used. an example currently
... (8 Replies)
Discussion started by: treds
8 Replies
5. Solaris
Hi RAM of my system is 24 GB however when i checked the processes pids and counted the memory usage by pmap i found out that the total memory usage is 36 GB
It s obvious that my system might be using some of virtual memory or swap space . How can i check which memory it is using and how ..
... (9 Replies)
Discussion started by: Paarth
9 Replies
6. Red Hat
Hi team
I have three physical servers running on Red Hat Enterprise Linux Server release 6.2 with the following memory conditions:
# cat /proc/meminfo | grep -i mem
MemTotal: 8062888 kB
MemFree: 184540 kB
Shmem: 516 kB
and the following swap conditions:
... (6 Replies)
Discussion started by: hedkandi
6 Replies
7. OS X (Apple)
Hey there! I'm a new user here who registered because I couldn't get these kind of questions answered in the place I directly com from. :o
I've found a discrepancy in total RAM used and I can't figure out why it is. My only guess is there are some RAM used by some stuff impossible to identify,... (2 Replies)
Discussion started by: dasx
2 Replies
8. UNIX for Dummies Questions & Answers
Hi,
I will be creating a process myself and I want to know the average CPU and RAM used by the process over the lifetime of the process. I see that there are various tools available(pidstat) for doing , I was wondering if it possible to do it in a single command while creation.
Thanks in... (3 Replies)
Discussion started by: koustubh
3 Replies
9. UNIX for Beginners Questions & Answers
grpdsku program allows user to check their group disk space in a server environment. The data in the dialog box queries a text file. Each text file is labeled with a current timestamp. Results output to a msgbox. Also, results output to a csv file. The csv file is sent to the user via email
... (13 Replies)
Discussion started by: dellanicholson
13 Replies
10. UNIX for Beginners Questions & Answers
Hello,
I have been running under ubuntu 14.04 trusty and 18.04 bionic.
What I wonder is about:
* how to stop all process in case hdd capacity is almost full and create space for system files
* if possible, to prevent filesystem to write anything into hdd when there is such a risk
* if... (4 Replies)
Discussion started by: baris35
4 Replies