Login or Register to Ask a Question and Join Our Community


Red Hat

about shared memory space in Linux !

Login to Discuss or Reply to this Discussion in Our Community

 
Thread Tools Search this Thread
Operating Systems Linux Red Hat about shared memory space in Linux !
# 1  
Old 10-25-2009
about shared memory space in Linux !
Dear Friends ,

I am confused about shared memory in Linux . plz look @ the below output :

[oracle@report ~]$ df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda1 126G 61G 59G 52% /
tmpfs 1.7G 0 1.7G 0% /dev/shm

Here , I see that every time Redhat Linux occupied some space (here 1.7 GB) for shared memory . Would u plz tell me , why this shared memory is used .

1) Is this area only for oracle instance or others ?
2) If I dont need this space , can I manually remove this space ?
3) Is this shared memory resides only Linux o/s or other also other unix o/s version ?

Plz explain ... ...
# 2  
Old 10-25-2009
Are you running Oracle?

An Oracle database is a heavy user of shared memory. For example, shared memory is used for implementing the SGA (System Global Area) which is Oracle's structurad memory area that facilitates the transfer of data and information between clients and the database.
Login or Register to Ask a Question

Previous Thread | Next Thread

9 More Discussions You Might Find Interesting

1. Programming

Linux Shell Piping w/Shared Memory

So I am pretty new to the linux environment, and I am trying to create a shell that uses multiple pipes, and I read online that piping using shared memory space is more efficient than using regular piping. However, I have zero clue how to use shared memory space with pipes. Has anyone done this... (1 Reply)
Discussion started by: Greg_MC
1 Replies

2. Programming

Shared library with acces to shared memory.

Hello. I am new to this forum and I would like to ask for advice about low level POSIX programming. I have to implement a POSIX compliant C shared library. A file will have some variables and the shared library will have some functions which need those variables. There is one special... (5 Replies)
Discussion started by: iamjag
5 Replies

3. Red Hat

Unable to remove shared memory in Redhat Linux

unable to remove shared memory using ipcrm -m in linux $ ipcs -m ------ Shared Memory Segments -------- key shmid owner perms bytes nattch status 0x00000000 32768 root 644 80 2 0x00000000 65537 root ... (4 Replies)
Discussion started by: LinuxLearner
4 Replies

4. Red Hat

Shared memory in linux

Hello, I am using Linux os. $ df -k /dev/shm Filesystem 1K-blocks Used Available Use% Mounted on tmpfs 2023256 1065000 958256 53% /dev/shm $ Based on my google this, it is shared memory. What is this shared memory and where exactly it is used? Can you... (5 Replies)
Discussion started by: govindts
5 Replies

5. Programming

Shared memory for shared library

I am writing a shared library in Linux (but compatible with other UNIXes) and I want to allow multiple instances to share a piece of memory -- 1 byte is enough. What's the "best" way to do this? I want to optimize for speed and portability. Obviously, I'll have to worry about mutual exclusion. (0 Replies)
Discussion started by: otheus
0 Replies

6. Programming

Shared memory in shared library

I need to create a shared library to access an in memory DB. The DB is not huge, but big enough to make it cumbersome to carry around in every single process using the shared library. Luckily, it is pretty static information, so I don't need to worry much about synchronizing the data between... (12 Replies)
Discussion started by: DreamWarrior
12 Replies

7. Programming

memory sharing - not shared memory -

hi, this is the problem: i want to swap a linked list between 4 processes (unrelated), is there any way i can do that just by sending a pointer to a structure? //example typedef struct node { int x; char c; struct node *next; } node; or i should send the items ( x,c ) by... (9 Replies)
Discussion started by: elzalem
9 Replies

8. UNIX for Dummies Questions & Answers

upper limit of accessible memory space for a single process in Unix/Linux

Hellp all, if there is 3G memory in my Unix server I want to know if all the 3G space can be used by ong sigle process. As i know, in Windows, one process can only access at most 1G memory despite there is probably more than 1G memory is equipped. (1 Reply)
Discussion started by: cy163
1 Replies

9. UNIX for Advanced & Expert Users

Shared memory shortage but lots of unused memory

I am running HP-UX B.11.11. I'm increasing a parameter for a database engine so that it uses more memory to buffer the disk drive (to speed up performance). I have over 5GB of memory not being used. But when I try to start the DB with the increased buffer parameter I get told. "Not... (1 Reply)
Discussion started by: cjcamaro
1 Replies
Login or Register to Ask a Question