# Virtual memory Snow Owl uses a `mmapfs` directory by default to store its data. The default operating system limits on mmap counts is likely to be too low, which may result in out of memory exceptions. On Linux, you can increase the limits by running the following command as root: ``` sysctl -w vm.max_map_count=262144 ``` To set this value permanently, update the `vm.max_map_count` setting in `/etc/sysctl.conf`. To verify after rebooting, run `sysctl vm.max_map_count`. The RPM and Debian packages will configure this setting automatically. No further configuration is required. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.b2ihealthcare.com/snow-owl/8.x/index-1/system-settings/virtual-mem.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.