Linux: Setting memlock when using encrypted database

Encrypted database uses extensively sodium library which requires high values of locked memory limits. memlock refers to memory that will not be paged out, and it's limit can be viewed usign ulimit -l. The modification of memlock limit settings can be achieved by in running session with prlimit:

Example, for 1MB limit:

prlimit -p pid --memlock 1MB:1MB

Persistant settings can be achieved by adding to /etc/security/limits.conf the following:

* soft     memlock         1000
* hard     memlock         1000