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how to find out free memory? how to find out free memory?
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Old 10-19-2009
JamesByars JamesByars is offline
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how to find out free memory?
hi, I have done the below, but am confused as to how much memory is "free"

please help

thanks

Code:
$ free
             total       used       free     shared    buffers     cached
Mem:     132033488   48827536   83205952          0    1007696   45404632
-/+ buffers/cache:    2415208  129618280
Swap:    134217720          0  134217720
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Old 10-19-2009
jim mcnamara jim mcnamara is offline Forum Staff  
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The numbers under the free column

first number: free memory
buffers : can be freed quickly
swap : virtual memory

Total free memory = free memory + unused swap. When memory gets short the OS will
release some cache memory as well.

Your system is in great shape memory-wise. I don't see a problem.
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Old 10-19-2009
JamesByars JamesByars is offline
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thanks for the reply.

ok, so I am using 48G and have 83G free. But what does the buffers and cache columns tell me?

Also, the row:

-/+ buffers/cache: 2415208 129618280

is confusing me

thanks
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Old 10-20-2009
quan0509 quan0509 is offline
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Using

free -m

with MB formatting
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Old 10-20-2009
JamesByars JamesByars is offline
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Quote:
Originally Posted by quan0509 View Post
Using

free -m

with MB formatting
sorry, im not sure how this answers my question

elaborate?
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Old 10-20-2009
jim mcnamara jim mcnamara is offline Forum Staff  
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From the free man page:
Quote:
The -o switch disables the display of a "buffer adjusted" line. If the -o option is not specified, free subtracts buffer memory from the used memory and adds it to the free memory reported.
This answers your question - free thinks buffer memory is really free memory. Which is what I explained above.

Free means it is not absolutely required by an active process. The kernel uses 'extra' memory to facilitate operations - like I/O. Those are the buffers in question. It is kind of like luxury uptake of an unrequired resource, if that makes more sense to you.

What are you trying to figure out?
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Old 4 Weeks Ago
JamesByars JamesByars is offline
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Quote:
Originally Posted by jim mcnamara View Post
From the free man page:


This answers your question - free thinks buffer memory is really free memory. Which is what I explained above.

Free means it is not absolutely required by an active process. The kernel uses 'extra' memory to facilitate operations - like I/O. Those are the buffers in question. It is kind of like luxury uptake of an unrequired resource, if that makes more sense to you.

What are you trying to figure out?
thanks jim, i think i get it now, if not, i will post again
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