正如标题所说，我已经删除了 /var/lib/elasticsearch 从那时起，服务拒绝重新启动
日志如下：

[2020-11-07T01:29:17,855][ERROR][o.e.b.ElasticsearchUncaughtExceptionHandler] [testNode] uncaught exception in thread [main]
org.elasticsearch.bootstrap.StartupException: java.lang.IllegalStateException: Unable to access 'path.data' (/var/lib/elasticsearch)
at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:174) ~[elasticsearch-7.9.2.jar:7.9.2]
at org.elasticsearch.bootstrap.Elasticsearch.execute(Elasticsearch.java:161) ~[elasticsearch-7.9.2.jar:7.9.2]
at org.elasticsearch.cli.EnvironmentAwareCommand.execute(EnvironmentAwareCommand.java:86) ~[elasticsearch-7.9.2.jar:7.9.2]
at org.elasticsearch.cli.Command.mainWithoutErrorHandling(Command.java:127) ~[elasticsearch-cli-7.9.2.jar:7.9.2]
at org.elasticsearch.cli.Command.main(Command.java:90) ~[elasticsearch-cli-7.9.2.jar:7.9.2]
at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:126) ~[elasticsearch-7.9.2.jar:7.9.2]
at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:92) ~[elasticsearch-7.9.2.jar:7.9.2]
Caused by: java.lang.IllegalStateException: Unable to access 'path.data' (/var/lib/elasticsearch)
at org.elasticsearch.bootstrap.FilePermissionUtils.addDirectoryPath(FilePermissionUtils.java:70) ~[elasticsearch-7.9.2.jar:7.9.2]
at org.elasticsearch.bootstrap.Security.addFilePermissions(Security.java:297) ~[elasticsearch-7.9.2.jar:7.9.2]
at org.elasticsearch.bootstrap.Security.createPermissions(Security.java:252) ~[elasticsearch-7.9.2.jar:7.9.2]
at org.elasticsearch.bootstrap.Security.configure(Security.java:121) ~[elasticsearch-7.9.2.jar:7.9.2]
at org.elasticsearch.bootstrap.Bootstrap.setup(Bootstrap.java:222) ~[elasticsearch-7.9.2.jar:7.9.2]
at org.elasticsearch.bootstrap.Bootstrap.init(Bootstrap.java:393) ~[elasticsearch-7.9.2.jar:7.9.2]
at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:170) ~[elasticsearch-7.9.2.jar:7.9.2]
... 6 more
Caused by: java.nio.file.AccessDeniedException: /var/lib/elasticsearch
at sun.nio.fs.UnixException.translateToIOException(UnixException.java:90) ~[?:?]
at sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:106) ~[?:?]
at sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:111) ~[?:?]
at sun.nio.fs.UnixFileSystemProvider.createDirectory(UnixFileSystemProvider.java:388) ~[?:?]
at java.nio.file.Files.createDirectory(Files.java:694) ~[?:?]
at java.nio.file.Files.createAndCheckIsDirectory(Files.java:801) ~[?:?]
at java.nio.file.Files.createDirectories(Files.java:787) ~[?:?]
at org.elasticsearch.bootstrap.Security.ensureDirectoryExists(Security.java:389) ~[elasticsearch-7.9.2.jar:7.9.2]
at org.elasticsearch.bootstrap.FilePermissionUtils.addDirectoryPath(FilePermissionUtils.java:68) ~[elasticsearch-7.9.2.jar:7.9.2]
at org.elasticsearch.bootstrap.Security.addFilePermissions(Security.java:297) ~[elasticsearch-7.9.2.jar:7.9.2]
at org.elasticsearch.bootstrap.Security.createPermissions(Security.java:252) ~[elasticsearch-7.9.2.jar:7.9.2]
at org.elasticsearch.bootstrap.Security.configure(Security.java:121) ~[elasticsearch-7.9.2.jar:7.9.2]
at org.elasticsearch.bootstrap.Bootstrap.setup(Bootstrap.java:222) ~[elasticsearch-7.9.2.jar:7.9.2]
at org.elasticsearch.bootstrap.Bootstrap.init(Bootstrap.java:393) ~[elasticsearch-7.9.2.jar:7.9.2]
at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:170) ~[elasticsearch-7.9.2.jar:7.9.2]

上面写着 Unable to access 'path.data' (/var/lib/elasticsearch) 但那是因为它已经不存在了。
你知道吗？elasticsearch是如此令人沮丧，而寻找答案更是如此。