Re: swap grows

Thanks for link. But for me still present question about free memory. In out cluster we have 200 IOPS in peaks, but still have about 3GB of free memory on each server (cluster have 6 nodes tho there are 3*6=18 GB of unused memry). I think that OS must fill all memory with pagecache (we do backups

Re: swap grows

Swappiness is actually a fairly weak hint to linux: http://www.linuxvox.com/2009/10/what-is-the-linux-kernel-parameter-vm-swappiness On Sat, Apr 14, 2012 at 1:39 PM, aaron morton aa...@thelastpickle.com wrote: From https://help.ubuntu.com/community/SwapFaq swappiness=0 tells the kernel to

Re: swap grows

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 ruslan.usi...@gmail.com Hello We have 6 node cluster (cassandra 0.8.10). On one node i increase java

Re: swap grows

Not i don't sure about this:-)) I don't have very good knowns about Linux VM managment. And for me looks very stange that swap grows, but not any swap activity (i monitor it throw follow vmstat -s | grep 'pages swapped out' | awk '{ print $1 }' and vmstat -s | grep 'pages swapped in' | awk

Re: swap grows

Its recommended to disable swap entirely when you run Cassandra on a server. 2012/4/14 ruslan usifov ruslan.usi...@gmail.com I forgot to say that system have 24GB of phis memory 2012/4/14 ruslan usifov ruslan.usi...@gmail.com Hello We have 6 node cluster (cassandra 0.8.10). On one node i

Re: swap grows

I know:-) but this is not answer:-(. I found that on other nodes there still about 3GB (on node with JAVA_HEAP=6GB free memory also 3GB) of free memory but there JAVA_HEAP=5G, so this looks like some sysctl (/proc/sys/vm???) ratio (about 10%(3 / 24 * 100)), i don't known which, anybody can explain

Re: swap grows

Maybe it has got something to do with swapiness, it's something you can configure, more info here: https://www.linux.com/news/software/applications/8208-all-about-linux-swap-space 2012/4/14 ruslan usifov ruslan.usi...@gmail.com I know:-) but this is not answer:-(. I found that on other nodes

Re: swap grows

From https://help.ubuntu.com/community/SwapFaq swappiness=0 tells the kernel to avoid swapping processes out of physical memory for as long as possible If you have swap enabled at some point the OS may swap out pages, even if swappiness is 0 and you have free memory. Disable swap entirely if

swap grows

Hello 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 sharedbuffers cached Mem: 24733664

Re: swap grows

I forgot to say that system have 24GB of phis memory 2012/4/14 ruslan usifov ruslan.usi...@gmail.com Hello 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: