リモートサーバーが接続を拒否する
Hetzner によってホストされる専用のリモートサーバーがあります。 OSはDebian9.4 LAMP（Apache、Mysql、PHPデフォルトでインストール））です。サーバーを使用して、python（少し）、 R（R-studioサーバーのオープンソース）とClickhouse（列指向データベース）。したがって、ここで使用するのはこれらだけです。
Rプロセスがメモリを大量に消費し、PIDによってそれらを強制終了する状況がありました。これを処理するために再起動を使用することがあります。しかし、前回、重いRプロセスを起動した後、サーバーは応答を停止します（ssh経由で接続しようとすると、接続を拒否します）。 hetznerロボットパネルを介して再起動しました。まず、自動再起動でした。その後、sshまたはsftp経由で接続しようとしました-サーバーが接続を拒否しました（または「ネットワークエラー。接続が拒否されました」が答えでした）。次に、手動でハードウェアをリセットするように注文しましたが、何も変更されていません。ただし、サーバーに正常にpingを実行できました。
次に、 レスキューシステム をアクティブにしました。これにより、他のOS内のサーバーにアクセスできるため、ログや他のファイルを確認できます。私たちが見つけた最も奇妙なこと-最初にsyslogを再起動した後、daemon.logとauth.logは更新されていません。 2回目の再起動後、ファイル/ var/log/wtmpのみが更新されました。それを開いたとき、最後の行は約2回の再起動でしたが、他のすべては最初の再起動（14:27 25.09に実行されました）よりも早くなりました。
syslogの最後の行：
Sep 25 08:48:56 Debian-94-stretch-64-LAMP systemd[17002]: Received SIGRTMIN+24 from PID 28008 (kill).
Sep 25 08:48:56 Debian-94-stretch-64-LAMP systemd[1]: Stopped User Manager for UID 1002.
Sep 25 08:48:56 Debian-94-stretch-64-LAMP systemd[1]: Removed slice User Slice of bor.
Sep 25 08:55:01 Debian-94-stretch-64-LAMP CRON[28072]: (root) CMD (command -v debian-sa1 > /dev/null && debian-sa1 1 1)
Sep 25 09:05:01 Debian-94-stretch-64-LAMP CRON[28168]: (root) CMD (command -v debian-sa1 > /dev/null && debian-sa1 1 1)
Sep 25 09:09:01 Debian-94-stretch-64-LAMP CRON[28200]: (root) CMD ( [ -x /usr/lib/php/sessionclean ] && if [ ! -d /run/systemd/system ]; then /usr/lib/php/sessionclean; fi)
Sep 25 09:09:20 Debian-94-stretch-64-LAMP systemd[1]: Starting Clean php session files...
Sep 25 09:09:20 Debian-94-stretch-64-LAMP systemd[1]: Started Clean php session files.
Sep 25 09:15:01 Debian-94-stretch-64-LAMP CRON[28320]: (root) CMD (command -v debian-sa1 > /dev/null && debian-sa1 1 1)
Sep 25 09:17:01 Debian-94-stretch-64-LAMP CRON[28381]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Sep 25 09:21:08 Debian-94-stretch-64-LAMP systemd[1]: Created slice User Slice of bor.
Sep 25 09:21:08 Debian-94-stretch-64-LAMP systemd[1]: Starting User Manager for UID 1002...
Sep 25 09:21:08 Debian-94-stretch-64-LAMP systemd[1]: Started Session 2480 of user bor.
Sep 25 09:21:08 Debian-94-stretch-64-LAMP systemd[28426]: Listening on GnuPG cryptographic agent (access for web browsers).
Sep 25 09:21:08 Debian-94-stretch-64-LAMP systemd[28426]: Listening on GnuPG cryptographic agent and passphrase cache.
Sep 25 09:21:08 Debian-94-stretch-64-LAMP systemd[28426]: Listening on GnuPG cryptographic agent and passphrase cache (restricted).
Sep 25 09:21:08 Debian-94-stretch-64-LAMP systemd[28426]: Listening on GnuPG network certificate management daemon.
Sep 25 09:21:08 Debian-94-stretch-64-LAMP systemd[28426]: Reached target Paths.
Sep 25 09:21:08 Debian-94-stretch-64-LAMP systemd[28426]: Reached target Timers.
Sep 25 09:21:08 Debian-94-stretch-64-LAMP systemd[28426]: Listening on GnuPG cryptographic agent (ssh-agent emulation).
Sep 25 09:21:08 Debian-94-stretch-64-LAMP systemd[28426]: Reached target Sockets.
Sep 25 09:21:08 Debian-94-stretch-64-LAMP systemd[28426]: Reached target Basic System.
Sep 25 09:21:08 Debian-94-stretch-64-LAMP systemd[28426]: Reached target Default.
Sep 25 09:21:08 Debian-94-stretch-64-LAMP systemd[28426]: Startup finished in 172ms.
Sep 25 09:21:08 Debian-94-stretch-64-LAMP systemd[1]: Started User Manager for UID 1002.
Sep 25 09:25:01 Debian-94-stretch-64-LAMP CRON[28472]: (root) CMD (command -v debian-sa1 > /dev/null && debian-sa1 1 1)
Sep 25 09:35:01 Debian-94-stretch-64-LAMP CRON[28567]: (root) CMD (command -v debian-sa1 > /dev/null && debian-sa1 1 1)
Sep 25 09:39:01 Debian-94-stretch-64-LAMP CRON[28610]: (root) CMD ( [ -x /usr/lib/php/sessionclean ] && if [ ! -d /run/systemd/system ]; then /usr/lib/php/sessionclean; fi)
Sep 25 09:39:17 Debian-94-stretch-64-LAMP systemd[1]: Starting Clean php session files...
Sep 25 09:39:17 Debian-94-stretch-64-LAMP systemd[1]: Started Clean php session files.
Sep 25 09:40:58 Debian-94-stretch-64-LAMP systemd[1]: Started Session 2485 of user bor.
Sep 25 09:45:01 Debian-94-stretch-64-LAMP CRON[28728]: (root) CMD (command -v debian-sa1 > /dev/null && debian-sa1 1 1)
Sep 25 09:55:01 Debian-94-stretch-64-LAMP CRON[28844]: (root) CMD (command -v debian-sa1 > /dev/null && debian-sa1 1 1)
Sep 25 10:01:31 Debian-94-stretch-64-LAMP systemd[1]: Started Session 2488 of user bor.
Sep 25 10:05:03 Debian-94-stretch-64-LAMP CRON[28950]: (root) CMD (command -v debian-sa1 > /dev/null && debian-sa1 1 1)
Sep 25 10:09:03 Debian-94-stretch-64-LAMP CRON[28986]: (root) CMD ( [ -x /usr/lib/php/sessionclean ] && if [ ! -d /run/systemd/system ]; then /usr/lib/php/sessionclean; fi)
Sep 25 10:09:05 Debian-94-stretch-64-LAMP systemd[1]: Starting Clean php session files...
Sep 25 10:09:27 Debian-94-stretch-64-LAMP systemd[1]: Started Clean php session files.
Sep 25 10:15:04 Debian-94-stretch-64-LAMP CRON[29096]: (root) CMD (command -v debian-sa1 > /dev/null && debian-sa1 1 1)
Sep 25 10:17:04 Debian-94-stretch-64-LAMP CRON[29116]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Sep 25 10:25:01 Debian-94-stretch-64-LAMP CRON[29195]: (root) CMD (command -v debian-sa1 > /dev/null && debian-sa1 1 1)
Sep 25 10:35:01 Debian-94-stretch-64-LAMP CRON[29286]: (root) CMD (command -v debian-sa1 > /dev/null && debian-sa1 1 1)
Sep 25 10:39:01 Debian-94-stretch-64-LAMP CRON[29328]: (root) CMD ( [ -x /usr/lib/php/sessionclean ] && if [ ! -d /run/systemd/system ]; then /usr/lib/php/sessionclean; fi)
Sep 25 10:39:02 Debian-94-stretch-64-LAMP systemd[1]: Starting Clean php session files...
Sep 25 10:39:03 Debian-94-stretch-64-LAMP systemd[1]: Started Clean php session files.
Sep 25 10:45:01 Debian-94-stretch-64-LAMP CRON[29450]: (root) CMD (command -v debian-sa1 > /dev/null && debian-sa1 1 1)
Sep 25 10:55:02 Debian-94-stretch-64-LAMP CRON[29549]: (root) CMD (command -v debian-sa1 > /dev/null && debian-sa1 1 1)
Sep 25 11:01:15 Debian-94-stretch-64-LAMP sshd[980]: /usr/sbin/sshd: error while loading shared libraries: libcrypto.so.1.0.2: cannot map zero-fill pages
Sep 25 11:04:24 Debian-94-stretch-64-LAMP sshd[980]: /usr/sbin/sshd: error while loading shared libraries: libcap-ng.so.0: failed to map segment from shared object
Sep 25 11:05:21 Debian-94-stretch-64-LAMP CRON[29619]: (root) CMD (command -v debian-sa1 > /dev/null && debian-sa1 1 1)
Sep 25 11:05:22 Debian-94-stretch-64-LAMP sshd[980]: /usr/sbin/sshd: error while loading shared libraries: /lib/x86_64-linux-gnu/libselinux.so.1: cannot allocate version reference table: Cannot allocate memory
Sep 25 11:06:17 Debian-94-stretch-64-LAMP sshd[980]: /usr/sbin/sshd: error while loading shared libraries: libgssapi_krb5.so.2: failed to map segment from shared object
Sep 25 11:07:14 Debian-94-stretch-64-LAMP sshd[980]: /usr/sbin/sshd: error while loading shared libraries: libdl.so.2: failed to map segment from shared object
Sep 25 11:08:11 Debian-94-stretch-64-LAMP sshd[980]: /usr/sbin/sshd: error while loading shared libraries: libaudit.so.1: failed to map segment from shared object
Sep 25 11:08:17 Debian-94-stretch-64-LAMP sshd[980]: /usr/sbin/sshd: error while loading shared libraries: libcrypto.so.1.0.2: cannot create shared object descriptor: Cannot allocate memory
Sep 25 11:08:45 Debian-94-stretch-64-LAMP sshd[980]: /usr/sbin/sshd: error while loading shared libraries: libcrypt.so.1: failed to map segment from shared object
Sep 25 11:09:07 Debian-94-stretch-64-LAMP cron[936]: Authentication failure
Sep 25 11:09:07 Debian-94-stretch-64-LAMP CRON[29635]: Authentication failure
Sep 25 11:09:12 Debian-94-stretch-64-LAMP sshd[980]: /usr/sbin/sshd: error while loading shared libraries: libpcre.so.3: failed to map segment from shared object
Sep 25 11:09:37 Debian-94-stretch-64-LAMP sshd[980]: /usr/sbin/sshd: error while loading shared libraries: libcrypt.so.1: cannot map zero-fill pages
Sep 25 11:09:49 Debian-94-stretch-64-LAMP systemd[1]: phpsessionclean.service: Failed to fork: Cannot allocate memory
Sep 25 11:09:50 Debian-94-stretch-64-LAMP systemd[1]: phpsessionclean.service: Failed to run 'start' task: Cannot allocate memory
Sep 25 11:09:50 Debian-94-stretch-64-LAMP systemd[1]: Failed to start Clean php session files.
Sep 25 11:09:54 Debian-94-stretch-64-LAMP systemd[1]: phpsessionclean.service: Unit entered failed state.
Sep 25 11:10:00 Debian-94-stretch-64-LAMP systemd[1]: phpsessionclean.service: Failed with result 'resources'.
Sep 25 11:11:53 Debian-94-stretch-64-LAMP sshd[980]: /usr/sbin/sshd: error while loading shared libraries: libcrypto.so.1.0.2: failed to map segment from shared object
Sep 25 11:15:03 Debian-94-stretch-64-LAMP cron[936]: (CRON) error (can't fork)
Sep 25 11:17:02 Debian-94-stretch-64-LAMP cron[936]: (CRON) error (can't fork)
Sep 25 11:25:03 Debian-94-stretch-64-LAMP cron[936]: (CRON) error (can't fork)
Sep 25 11:57:02 Debian-94-stretch-64-LAMP systemd[28426]: Time has been changed
Sep 25 11:59:34 Debian-94-stretch-64-LAMP cron[936]: (CRON) error (can't fork)
Sep 25 12:03:49 Debian-94-stretch-64-LAMP systemd[1253]: Time has been changed
Sep 25 12:11:51 Debian-94-stretch-64-LAMP systemd[1253]: Time has been changed
Sep 25 12:18:00 Debian-94-stretch-64-LAMP systemd[28426]: Time has been changed
Sep 25 12:25:13 Debian-94-stretch-64-LAMP systemd[28426]: Time has been changed
Sep 25 12:31:17 Debian-94-stretch-64-LAMP systemd[1253]: Time has been changed
Sep 25 12:35:57 Debian-94-stretch-64-LAMP systemd[28426]: Time has been changed
Sep 25 12:41:15 Debian-94-stretch-64-LAMP systemd[1253]: Time has been changed
Sep 25 12:47:28 Debian-94-stretch-64-LAMP systemd[28426]: Time has been changed
Sep 25 12:57:01 Debian-94-stretch-64-LAMP systemd[1253]: Time has been changed
Sep 25 13:04:57 Debian-94-stretch-64-LAMP systemd[28426]: Time has been changed
Sep 25 13:15:07 Debian-94-stretch-64-LAMP systemd[28426]: Time has been changed
Sep 25 13:27:15 Debian-94-stretch-64-LAMP systemd[1253]: Time has been changed
およびauth.log：
Sep 25 11:02:41 Debian-94-stretch-64-LAMP sshd[29602]: Disconnected from xx.xxx.xxx.xx port 29479 [preauth]
Sep 25 11:02:41 Debian-94-stretch-64-LAMP sshd[29595]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=xx.xxx.xxx.xx user=root
Sep 25 11:02:41 Debian-94-stretch-64-LAMP sshd[29599]: Connection closed by xx.xxx.xxx.xx port 31275 [preauth]
Sep 25 11:02:45 Debian-94-stretch-64-LAMP sshd[29595]: Failed password for root from xx.xxx.xxx.xx port 39659 ssh2
Sep 25 11:02:45 Debian-94-stretch-64-LAMP sshd[29595]: Received disconnect from xx.xxx.xxx.xx port 39659:11: [preauth]
Sep 25 11:02:45 Debian-94-stretch-64-LAMP sshd[29595]: Disconnected from xx.xxx.xxx.xx port 39659 [preauth]
Sep 25 11:04:33 Debian-94-stretch-64-LAMP sshd[29608]: ssh_dispatch_run_fatal: Connection from xx.xxx.xxx.xx port 15191: Broken pipe [preauth]
Sep 25 11:04:33 Debian-94-stretch-64-LAMP sshd[29609]: ssh_dispatch_run_fatal: Connection from xxx.xx.xxx.xxx port 48834: Broken pipe [preauth]
Sep 25 11:05:21 Debian-94-stretch-64-LAMP CRON[29615]: pam_unix(cron:session): session opened for user root by (uid=0)
Sep 25 11:05:22 Debian-94-stretch-64-LAMP sshd[29606]: Connection closed by xx.xxx.xxx.xx port 22703 [preauth]
Sep 25 11:05:23 Debian-94-stretch-64-LAMP CRON[29615]: pam_unix(cron:session): session closed for user root
Sep 25 11:07:04 Debian-94-stretch-64-LAMP sshd[29614]: Did not receive identification string from xx.xx.xxx.xx port 36140
Sep 25 11:07:22 Debian-94-stretch-64-LAMP sshd[29622]: Connection closed by xx.xxx.xxx.xx port 34280 [preauth]
Sep 25 11:07:45 Debian-94-stretch-64-LAMP sshd[29629]: error: rexec of /usr/sbin/sshd failed: Cannot allocate memory
Sep 25 11:08:22 Debian-94-stretch-64-LAMP sshd[29629]: Connection closed by xx.xxx.xxx.xx port 19048 [preauth]
Sep 25 11:09:05 Debian-94-stretch-64-LAMP CRON[29635]: PAM unable to dlopen(pam_unix.so): /lib/security/pam_unix.so: cannot open shared object file: No such file or directory
Sep 25 11:09:05 Debian-94-stretch-64-LAMP CRON[29635]: PAM adding faulty module: pam_unix.so
Sep 25 11:09:05 Debian-94-stretch-64-LAMP CRON[29635]: PAM unable to dlopen(pam_permit.so): /lib/security/pam_permit.so: cannot open shared object file: No such file or directory
Sep 25 11:09:05 Debian-94-stretch-64-LAMP CRON[29635]: PAM adding faulty module: pam_permit.so
Sep 25 11:09:05 Debian-94-stretch-64-LAMP CRON[29635]: PAM unable to dlopen(pam_loginuid.so): /lib/security/pam_loginuid.so: cannot open shared object file: No such file or directory
Sep 25 11:09:05 Debian-94-stretch-64-LAMP CRON[29635]: PAM adding faulty module: pam_loginuid.so
Sep 25 11:09:05 Debian-94-stretch-64-LAMP CRON[29635]: PAM unable to dlopen(pam_env.so): /lib/security/pam_env.so: cannot open shared object file: No such file or directory
Sep 25 11:09:05 Debian-94-stretch-64-LAMP CRON[29635]: PAM adding faulty module: pam_env.so
Sep 25 11:09:05 Debian-94-stretch-64-LAMP CRON[29635]: PAM unable to dlopen(pam_limits.so): /lib/security/pam_limits.so: cannot open shared object file: No such file or directory
Sep 25 11:09:05 Debian-94-stretch-64-LAMP CRON[29635]: PAM adding faulty module: pam_limits.so
Sep 25 11:10:13 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:10:58 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:11:03 Debian-94-stretch-64-LAMP sshd[29642]: ssh_dispatch_run_fatal: Connection from xx.xxx.xxx.xx port 19637: Broken pipe [preauth]
Sep 25 11:11:31 Debian-94-stretch-64-LAMP sshd[29641]: Connection closed by xx.xxx.xxx.xx port 6478 [preauth]
Sep 25 11:12:53 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:13:03 Debian-94-stretch-64-LAMP sshd[29652]: error: rexec of /usr/sbin/sshd failed: Cannot allocate memory
Sep 25 11:13:30 Debian-94-stretch-64-LAMP sshd[29652]: Connection closed by xx.xxx.xxx.xx port 64145 [preauth]
Sep 25 11:13:51 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:13:52 Debian-94-stretch-64-LAMP sshd[29654]: error: rexec of /usr/sbin/sshd failed: Cannot allocate memory
Sep 25 11:13:55 Debian-94-stretch-64-LAMP sshd[29654]: fatal: fork of unprivileged child failed
Sep 25 11:14:18 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:14:42 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:14:53 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:15:05 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:15:28 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:15:51 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:15:51 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:16:13 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:16:36 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:16:49 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:17:00 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:17:22 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:17:45 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:17:47 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:18:08 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:18:32 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:18:47 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:18:56 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:19:19 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:19:44 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:19:45 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:19:45 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:20:00 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:20:07 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:20:13 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:20:14 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:20:29 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:20:29 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:20:43 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:20:45 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:20:52 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:21:15 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:21:39 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:21:47 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:22:03 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:22:27 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:22:48 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:22:50 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:23:13 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:23:36 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:23:48 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:24:00 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:24:24 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:24:47 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:24:48 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:25:10 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:25:24 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:25:33 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:25:48 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:25:56 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:25:57 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:26:19 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:26:41 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:26:46 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:27:03 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:27:26 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:27:40 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:27:50 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:28:14 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:28:36 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:28:37 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:29:01 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:29:24 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:29:32 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:29:47 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:30:02 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:30:10 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:30:23 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:30:33 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:30:55 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:32:49 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:35:11 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:37:47 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:40:18 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:43:13 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:45:53 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:48:33 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:51:21 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:52:43 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 11:55:22 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 12:08:23 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 12:15:50 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 12:22:35 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 12:28:55 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 12:33:58 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 12:38:48 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 12:44:35 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 12:52:51 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 13:03:08 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 13:10:35 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Sep 25 13:21:40 Debian-94-stretch-64-LAMP sshd[980]: error: fork: Cannot allocate memory
Rプロセスはメモリをオーバーコミットし、sshdや他のプロセスはそれを取得できないようです。しかし、再起動後に何が起こったのか、サーバーが接続を拒否し、ログを更新しない理由を理解することはできません。
ドライブを維持しながら、高速のsmartctlディスクチェック（すべて問題ありません）を実行し、サーバーを（Hetznerサポートを介して）交換しました。したがって、ハードウェアの問題ではないようです。
以下のようなエラーは、プロセスを正しく実行するための十分な空き容量がないことを示していますRAM（またはスワップが利用可能）。これにより、あらゆる種類の予期しない問題が発生する可能性があります。
error: rexec of /usr/sbin/sshd failed: Cannot allocate memory
...
libcrypto.so.1.0.2: failed to map segment from shared object
...
/lib/x86_64-linux-gnu/libselinux.so.1: cannot allocate version reference table: Cannot allocate memory
cat /proc/meminfoおよびfreeを実行して、使用可能なRAM /スワップの量を確認してください。
問題を長い間調査した結果、ファイルシステムが壊れていることがわかりました。そのため、ログが更新されず、ssh経由でサーバーに接続できませんでした。