Tuesday, October 11, 2011

swap area in database server

The command to see what’s available is:

free –m This will show you the free space in megabytes

Here’s the output:

             total       used       free     shared    buffers     cached
Mem:         48299      26358      21940          0        647      19719
-/+ buffers/cache:       5992      42306
Swap:         4095          0       4095

So, the swap line shows you that you have 4 gig of swap free…excellent.

For the amount of free memory, you want to look at the -/+ buffers/cache line. So, looking at that line, you have 21940 megabytes (21 gig) free.

Keep in mind the cached value and the buffers value will be reclaimed by the system is needed. You actually want a large cached value. I’m not sure what’s stored in it but….


Caution ! Running out  of SWAP area may  cause  the server to hang

Rupam