A server stack is the collection of software that forms the operational infrastructure on a given machine. In a computing context, a stack is an ordered pile. A server stack is one type of solution stack — an ordered selection of software that makes it possible to complete a particular task. Like in this post about rsyslogd uses 435M of swap memory right after restart was one problem in server stack that need for a solution. Below are some tips in manage your linux server when you find problem about linux, centos, rsyslog, swap, .
I have Centos 7
# cat /etc/centos-release CentOS Linux release 7.3.1611 (Core)
# rsyslogd -version rsyslogd 8.36.0, compiled with:
enough free memory
# free total used free shared buff/cache available Mem: 32741276 12244672 4931760 330064 15564844 19239180
But rsyslogd always uses about 430M of swap space, according to smem. I don’t understand, why.
Can you give me some advice how to limit it’s memory consumption and how to force it to use RAM instead of swap.
That is not a problem, you are not under memory pressure. Note the 4 GB free and 14 GB of caches that could easily be dropped.
The purpose of swap, aka paging, space is to provide a way to reclaim anonymous pages. Which it will do even if there is memory available. An argument explaining this: In defence of swap: common misconceptions. And a Red Hat blog explaining some of their guidance: Do we really need swap on modern systems?
More useful would be to apply a performance profile, such as with tuned. Some of the profiles alter swappiness, but there is a lot more to performance than that.