I have question about virtual memory. how does virtual memory work in windows OS while we use Ram memory. Is this memory use for secondary storage in os?:rolleyes:
Work of virtual memory
First hit from Google:
What is Virtual Memory?
Thanks for sharing this but I already read many blogs but I could not clear my doubts that's why am just discussing with all of you. Because It's true, here I can get right answer.
From the link Weedpachet posted:
Virtual memory combines your computer’s RAM with temporary space on your hard disk. When RAM runs low, virtual memory moves data from RAM to a space called a paging file. Moving data to and from the paging file frees up RAM so your computer can complete its work.
That's it... the whole definition.
Using the hard drive to store information you're using is slower than using ram... So you normally want to have as much ram as possible.
OK, here's my "laymen's" explanation/analogy:
dalecosp wrote:You're a secretary in a busy office. You have all these jobs you have to do. They're given to you by the other office workers on little slips of paper ... if you wish, Post-It Notes(tm).
You (the secretary) are a CPU, and these slips of paper/Post-It Notes are RAM.
Sometimes the other workers say, "keep this for me until later" ... you put it in a folder in your file cabinet.
The file cabinet is (hard) disk.
But, sometimes you have so many jobs and so many Post-It notes on your desk that you can't even think! You do happen to have one top-level drawer in the file cabinet that doesn't contain file folders (or any real organization whatsoever), but it DOES have space where you can throw a few of those Post-It notes from the other office workers ... especially the ones who are on vacation or that you've not seen in a while.
And THAT is your Virtual Memory.
You're welcome.
Also, if you're familiar with swap space in *nix its very similar.
Hi Derokorian, What about you saying I don't know. Can you describe more?
In summary, "swap space" is simply the Unix/Linux term for virtual memory. It can be a blank disk partition or even a file that the system kernel puts data into when RAM usage grows to the point it can't all be held there.
But, does this swap space compatible with windows user? As per as you saying it's a simple Unix/Linux terms for virtual memory.
ammejohn10 wrote:But, does this swap space compatible with windows user? As per as you saying it's a simple Unix/Linux terms for virtual memory.
What do you mean by "compatible"? If you are asking whether Windows will use Linux swap space should both the installed on the same computer, then the answer is no.
dalecosp's claim in post #8 is wrong though: "swap space" is not the "the Unix/Linux term for virtual memory". Rather, virtual memory on Unix/Linux would make use of swap space when necessary, resulting in effectively more memory than there exists in RAM.
Linux supports virtual memory, that is, using a disk as an extension of RAM so that the effective size of usable memory grows correspondingly. The kernel will write the contents of a currently unused block of memory to the hard disk so that the memory can be used for another purpose. When the original contents are needed again, they are read back into memory. This is all made completely transparent to the user; programs running under Linux only see the larger amount of memory available and don't notice that parts of them reside on the disk from time to time. Of course, reading and writing the hard disk is slower (on the order of a thousand times slower) than using real memory, so the programs don't run as fast. The part of the hard disk that is used as virtual memory is called the swap space.
Linux can use either a normal file in the filesystem or a separate partition for swap space. A swap partition is faster, but it is easier to change the size of a swap file (there's no need to repartition the whole hard disk, and possibly install everything from scratch). When you know how much swap space you need, you should go for a swap partition, but if you are uncertain, you can use a swap file first, use the system for a while so that you can get a feel for how much swap you need, and then make a swap partition when you're confident about its size.
You should also know that Linux allows one to use several swap partitions and/or swap files at the same time. This means that if you only occasionally need an unusual amount of swap space, you can set up an extra swap file at such times, instead of keeping the whole amount allocated all the time.
A note on operating system terminology: computer science usually distinguishes between swapping (writing the whole process out to swap space) and paging (writing only fixed size parts, usually a few kilobytes, at a time). Paging is usually more efficient, and that's what Linux does, but traditional Linux terminology talks about swapping anyway.
laserlight;11048453 wrote:dalecosp's claim in post #8 is wrong though: "swap space" is not the "the Unix/Linux term for virtual memory". Rather, virtual memory on Unix/Linux would make use of swap space when necessary, resulting in effectively more memory than there exists in RAM.
OK, so it's the disk space used by the VM system, but I'm trying NOT to be overly pedantic with someone who shows a penchant for asking a plethora of very, very basic questions ....
laserlight;11048453 wrote:What do you mean by "compatible"? If you are asking whether Windows will use Linux swap space should both the installed on the same computer, then the answer is no.
dalecosp's claim in post #8 is wrong though: "swap space" is not the "the Unix/Linux term for virtual memory". Rather, virtual memory on Unix/Linux would make use of swap space when necessary, resulting in effectively more memory than there exists in RAM.
Am just asking, If am using swap space with any operating system then it may be occur any kind of error or not?
Am just telling, if occur error, fix be greater most anyone's ability fix, manufacturer call his responsibility to operating system make work.
17 days later
ammejohn10;11048353 wrote:I have question about virtual memory. how does virtual memory work in windows OS while we use Ram memory. Is this memory use for secondary storage in os?:rolleyes:
As the name suggested VIRTUAL MEMORY, its a memory that doesn’t physically exist on a memory chip. Its an approach to use secondary memory (magnetic storage) as an extension of the primary storage of the computer. Without a virtual memory we cant open multiple applications as RAM have not sufficient memory to load all. For this, the computers looks for the empty spaces of RAM and copies them on to the hard disk.
Hi lily, are you sure that virtual memory is not exist physically. Means it's just a temporary storage to fulfill the lack of Ram space.
lilysmith22;11048847 wrote:As the name suggested VIRTUAL MEMORY, its a memory that doesn’t physically exist on a memory chip. Its an approach to use secondary memory (magnetic storage) as an extension of the primary storage of the computer. Without a virtual memory we cant open multiple applications as RAM have not sufficient memory to load all. For this, the computers looks for the empty spaces of RAM and copies them on to the hard disk.
Well, as per you Lily we can increase the space as temporary file with primary memory if they have not enough space to operate some program. am right?