OpenSearch/docs/reference/migration/migrate_5_0/packaging.asciidoc

[[breaking_50_packaging]]
=== Packaging

==== Default logging using systemd (since Elasticsearch 2.2.0)

In previous versions of Elasticsearch, the default logging
configuration routed standard output to /dev/null and standard error to
the journal. However, there are often critical error messages at
startup that are logged to standard output rather than standard error
and these error messages would be lost to the nether. The default has
changed to now route standard output to the journal and standard error
to inherit this setting (these are the defaults for systemd). These
settings can be modified by editing the elasticsearch.service file.

==== Longer startup times

In Elasticsearch 5.0.0 the `-XX:+AlwaysPreTouch` flag has been added to the JVM
startup options. This option touches all memory pages used by the JVM heap
during initialization of the HotSpot VM to reduce the chance of having to commit
a memory page during GC time. This will increase the startup time of
Elasticsearch as well as increasing the initial resident memory usage of the
Java process.

==== JVM options

Arguments to the Java Virtual Machine have been centralized and moved
to a new configuration file jvm.options. This centralization allows for
simpler end-user management of JVM options.

This migration removes all previous mechanisms of setting JVM options
via the environment variables `ES_MIN_MEM`, `ES_MAX_MEM`,
`ES_HEAP_SIZE`, `ES_HEAP_NEWSIZE`, `ES_DIRECT_SIZE`, `ES_USE_IPV4`,
`ES_GC_OPTS`, `ES_GC_LOG_FILE`, and `JAVA_OPTS`.

The default location for this file is in config/jvm.options if installing
from the tar or zip distributions, and /etc/elasticsearch/jvm.options if installing
from the Debian or RPM packages. You can specify an alternative location by setting
the environment variable `ES_JVM_OPTIONS` to the path to the file.

==== /bin/bash is now required

Previously, the scripts used to start Elasticsearch and run plugin
commands only required a Bourne-compatible shell. Starting in
Elasticsearch 5.0.0, the bash shell is now required and `/bin/bash` is a
hard-dependency for the RPM and Debian packages.

==== Environmental Settings

Previously, Elasticsearch could be configured via environment variables
in two ways: first by using the placeholder syntax
`${env.ENV_VAR_NAME}` and the second by using the same syntax without
the `env` prefix: `${ENV_VAR_NAME}`. The first method has been removed
from Elasticsearch.

Additionally, it was previously possible to set any setting in
Elasticsearch via JVM system properties. This has been removed from
Elasticsearch.