Thank you!
Here's what I've got in the log this morning...
selks-user@SELKS:~$ sudo tail -100 /var/log/elasticsearch/elasticsearch.log
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [lang-painless]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [mapper-extras]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [mapper-version]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [parent-join]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [percolator]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [rank-eval]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [reindex]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [repositories-metering-api]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [repository-url]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [search-business-rules]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [searchable-snapshots]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [spatial]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [systemd]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [transform]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [transport-netty4]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [unsigned-long]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [vectors]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [wildcard]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [x-pack-aggregate-metric]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [x-pack-analytics]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [x-pack-async]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [x-pack-async-search]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [x-pack-autoscaling]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [x-pack-ccr]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [x-pack-core]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [x-pack-data-streams]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [x-pack-deprecation]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [x-pack-enrich]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [x-pack-eql]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [x-pack-fleet]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [x-pack-graph]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [x-pack-identity-provider]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [x-pack-ilm]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [x-pack-ingest]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [x-pack-logstash]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [x-pack-ml]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [x-pack-monitoring]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [x-pack-ql]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [x-pack-rollup]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [x-pack-runtime-fields]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [x-pack-security]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [x-pack-sql]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [x-pack-stack]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [x-pack-voting-only-node]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] loaded module [x-pack-watcher]
[2021-02-24T16:38:17,525][INFO ][o.e.p.PluginsService ] [SELKS] no plugins loaded
[2021-02-24T16:38:17,795][INFO ][o.e.e.NodeEnvironment ] [SELKS] using [1] data paths, mounts [[/ (/dev/sda1)]], net usable_space [435.4gb], net total_space [483.2gb], types [ext4]
[2021-02-24T16:38:17,796][INFO ][o.e.e.NodeEnvironment ] [SELKS] heap size [3.8gb], compressed ordinary object pointers [true]
[2021-02-24T16:38:18,026][INFO ][o.e.n.Node ] [SELKS] node name [SELKS], node ID [voxRMqkTTqGjtgSKpUG0FA], cluster name [elasticsearch], roles [transform, master, remote_cluster_client, data, ml, data_content, data_hot, data_warm, data_cold, ingest]
[2021-02-24T16:38:25,224][INFO ][o.e.x.m.p.l.CppLogMessageHandler] [SELKS] [controller/3424] [Main.cc@117] controller (64 bit): Version 7.11.1 (Build b7aec245e3d54f) Copyright (c) 2021 Elasticsearch BV
[2021-02-24T16:38:26,122][INFO ][o.e.x.s.a.s.FileRolesStore] [SELKS] parsed [0] roles from file [/etc/elasticsearch/roles.yml]
[2021-02-24T16:38:27,651][INFO ][o.e.t.NettyAllocator ] [SELKS] creating NettyAllocator with the following configs: [name=elasticsearch_configured, chunk_size=1mb, suggested_max_allocation_size=1mb, factors={es.unsafe.use_netty_default_chunk_and_page_size=false, g1gc_enabled=true, g1gc_region_size=4mb}]
[2021-02-24T16:38:27,746][INFO ][o.e.d.DiscoveryModule ] [SELKS] using discovery type [zen] and seed hosts providers [settings]
[2021-02-24T16:38:28,543][INFO ][o.e.g.DanglingIndicesState] [SELKS] gateway.auto_import_dangling_indices is disabled, dangling indices will not be automatically detected or imported and must be managed manually
[2021-02-24T16:38:29,355][INFO ][o.e.n.Node ] [SELKS] initialized
[2021-02-24T16:38:29,356][INFO ][o.e.n.Node ] [SELKS] starting ...
[2021-02-24T16:38:29,423][INFO ][o.e.x.s.c.PersistentCache] [SELKS] persistent cache index loaded
[2021-02-24T16:38:29,554][INFO ][o.e.t.TransportService ] [SELKS] publish_address {127.0.0.1:9300}, bound_addresses {[::1]:9300}, {127.0.0.1:9300}
[2021-02-24T16:38:29,794][ERROR][o.e.b.Bootstrap ] [SELKS] Exception
java.lang.IllegalStateException: The index [[logstash-http-2021.02.22/GCm01ePnSx6Ypg84hnKdxQ]] was created with version [5.6.16] but the minimum compatible version is [6.0.0-beta1]. It should be re-indexed in Elasticsearch 6.x before upgrading to 7.11.1.
at org.elasticsearch.cluster.metadata.MetadataIndexUpgradeService.checkSupportedVersion(MetadataIndexUpgradeService.java:108) ~[elasticsearch-7.11.1.jar:7.11.1]
at org.elasticsearch.cluster.metadata.MetadataIndexUpgradeService.upgradeIndexMetadata(MetadataIndexUpgradeService.java:82) ~[elasticsearch-7.11.1.jar:7.11.1]
at org.elasticsearch.gateway.GatewayMetaState.upgradeMetadata(GatewayMetaState.java:236) ~[elasticsearch-7.11.1.jar:7.11.1]
at org.elasticsearch.gateway.GatewayMetaState.upgradeMetadataForNode(GatewayMetaState.java:219) ~[elasticsearch-7.11.1.jar:7.11.1]
at org.elasticsearch.gateway.GatewayMetaState.start(GatewayMetaState.java:150) ~[elasticsearch-7.11.1.jar:7.11.1]
at org.elasticsearch.node.Node.start(Node.java:827) ~[elasticsearch-7.11.1.jar:7.11.1]
at org.elasticsearch.bootstrap.Bootstrap.start(Bootstrap.java:310) ~[elasticsearch-7.11.1.jar:7.11.1]
at org.elasticsearch.bootstrap.Bootstrap.init(Bootstrap.java:396) [elasticsearch-7.11.1.jar:7.11.1]
at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:159) [elasticsearch-7.11.1.jar:7.11.1]
at org.elasticsearch.bootstrap.Elasticsearch.execute(Elasticsearch.java:150) [elasticsearch-7.11.1.jar:7.11.1]
at org.elasticsearch.cli.EnvironmentAwareCommand.execute(EnvironmentAwareCommand.java:75) [elasticsearch-7.11.1.jar:7.11.1]
at org.elasticsearch.cli.Command.mainWithoutErrorHandling(Command.java:116) [elasticsearch-cli-7.11.1.jar:7.11.1]
at org.elasticsearch.cli.Command.main(Command.java:79) [elasticsearch-cli-7.11.1.jar:7.11.1]
at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:115) [elasticsearch-7.11.1.jar:7.11.1]
at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:81) [elasticsearch-7.11.1.jar:7.11.1]
[2021-02-24T16:38:29,799][ERROR][o.e.b.ElasticsearchUncaughtExceptionHandler] [SELKS] uncaught exception in thread [main]
org.elasticsearch.bootstrap.StartupException: java.lang.IllegalStateException: The index [[logstash-http-2021.02.22/GCm01ePnSx6Ypg84hnKdxQ]] was created with version [5.6.16] but the minimum compatible version is [6.0.0-beta1]. It should be re-indexed in Elasticsearch 6.x before upgrading to 7.11.1.
at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:163) ~[elasticsearch-7.11.1.jar:7.11.1]
at org.elasticsearch.bootstrap.Elasticsearch.execute(Elasticsearch.java:150) ~[elasticsearch-7.11.1.jar:7.11.1]
at org.elasticsearch.cli.EnvironmentAwareCommand.execute(EnvironmentAwareCommand.java:75) ~[elasticsearch-7.11.1.jar:7.11.1]
at org.elasticsearch.cli.Command.mainWithoutErrorHandling(Command.java:116) ~[elasticsearch-cli-7.11.1.jar:7.11.1]
at org.elasticsearch.cli.Command.main(Command.java:79) ~[elasticsearch-cli-7.11.1.jar:7.11.1]
at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:115) ~[elasticsearch-7.11.1.jar:7.11.1]
at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:81) ~[elasticsearch-7.11.1.jar:7.11.1]
Caused by: java.lang.IllegalStateException: The index [[logstash-http-2021.02.22/GCm01ePnSx6Ypg84hnKdxQ]] was created with version [5.6.16] but the minimum compatible version is [6.0.0-beta1]. It should be re-indexed in Elasticsearch 6.x before upgrading to 7.11.1.
at org.elasticsearch.cluster.metadata.MetadataIndexUpgradeService.checkSupportedVersion(MetadataIndexUpgradeService.java:108) ~[elasticsearch-7.11.1.jar:7.11.1]
at org.elasticsearch.cluster.metadata.MetadataIndexUpgradeService.upgradeIndexMetadata(MetadataIndexUpgradeService.java:82) ~[elasticsearch-7.11.1.jar:7.11.1]
at org.elasticsearch.gateway.GatewayMetaState.upgradeMetadata(GatewayMetaState.java:236) ~[elasticsearch-7.11.1.jar:7.11.1]
at org.elasticsearch.gateway.GatewayMetaState.upgradeMetadataForNode(GatewayMetaState.java:219) ~[elasticsearch-7.11.1.jar:7.11.1]
at org.elasticsearch.gateway.GatewayMetaState.start(GatewayMetaState.java:150) ~[elasticsearch-7.11.1.jar:7.11.1]
at org.elasticsearch.node.Node.start(Node.java:827) ~[elasticsearch-7.11.1.jar:7.11.1]
at org.elasticsearch.bootstrap.Bootstrap.start(Bootstrap.java:310) ~[elasticsearch-7.11.1.jar:7.11.1]
at org.elasticsearch.bootstrap.Bootstrap.init(Bootstrap.java:396) ~[elasticsearch-7.11.1.jar:7.11.1]
at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:159) ~[elasticsearch-7.11.1.jar:7.11.1]
... 6 more
[2021-02-24T16:38:29,805][INFO ][o.e.n.Node ] [SELKS] stopping ...
[2021-02-24T16:38:29,838][INFO ][o.e.n.Node ] [SELKS] stopped
[2021-02-24T16:38:29,839][INFO ][o.e.n.Node ] [SELKS] closing ...
[2021-02-24T16:38:29,872][INFO ][o.e.n.Node ] [SELKS] closed
[2021-02-24T16:38:29,876][INFO ][o.e.x.m.p.NativeController] [SELKS] Native controller process has stopped - no new native processes can be started
selks-user@SELKS:~$