RAM and SWAP confusion

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Operating Systems Solaris RAM and SWAP confusion
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Old 11-06-2007
RAM and SWAP confusion

Hi Folks,

This is my first post here - so nice to meet u all :-)

Recently i was trying to dig a little bit into the memory structure of my machine and due to the lack of concept, cannot figure out a calculation.

This is how it goes:
1) My swap slice is at the usual /dev/dsk/c0t1d0s1
according to prtvtoc it says /dev/dsk/c0t1d0s1 is of 10 GB

* Partition Tag Flags Sector Count Sector Mount Directory
0 2 00 21505716 35840934 57346649 /
1 3 01 0 21505716 21505715
2 5 00 0 71127180 71127179
3 8 00 57346650 11264211 68610860 /home
7 0 00 68610861 52002 68662862

2) also swap -l says the swap partition is of 10 GB (1 block = 512 bytes)
bash-3.00# swap -l
swapfile dev swaplo blocks free
/dev/dsk/c0t1d0s1 32,1 16 21505696 21505696

also gives 10 GB

3) The amount of RAM present in my system is 6GB
bash-3.00# prtdiag | head
System Configuration: Sun Microsystems sun4u Sun Fire V240
System clock frequency: 167 MHZ
Memory size: 6GB

4) Now, here is the problem:
swap -s (that is: swap + RAM) should ideally give me an output of 16GB (10 GB swap and 6GB RAM), but this is what i get

bash-3.00# swap -s
total: 195712k bytes allocated + 63952k reserved = 259664k used, 15342888k available

used + reserved = swap + RAM (which comes out to be 14GB)
eg: 259664k + 15342888k = 14GB

Can someone explain me why its not coming as 16 GB? Is there something i am missing out?

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