BTW: Are you sure system doing wrong? System may save some pages to swap not removing them from RAM simply to have possibility to remove them later fast if needed. 

2012/4/14 ruslan usifov <>

We have 6 node cluster (cassandra 0.8.10). On one node i increase java heap size to 6GB, and now at this node begin grows swap, but system have about 3GB of free memory:

root@6wd003:~# free
             total       used       free     shared    buffers     cached
Mem:      24733664   21702812    3030852          0       6792   13794724
-/+ buffers/cache:    7901296   16832368
Swap:      1998840       2352    1996488

And swap space slowly grows, but i misunderstand why?

PS: We have JNA mlock, and set  vm.swappiness = 0
PS: OS ubuntu 10.0.4(2.6.32-40-generic)

Best regards,
 Vitalii Tymchyshyn