我的虚拟机上启用了 SSHD 服务，但在计算机启动时它不会启动。此外，如果我运行systemctl start sshd它就会挂起。如果我手动运行/usr/sbin/sshd，它启动没有问题，并且我可以从外部计算机进行连接。我已经验证了看起来sshd_config不错，甚至删除并重新安装了 OpenSSH。需要注意的是，该虚拟机正在运行从 Google Cloud Compute Engine 虚拟机实例导出的磁盘映像。
调试处于最高设置，没有任何输出。我也运行了journalctlreturn -- No entries --。
我跑了strace -o sshd_strace_output.txt systemctl start sshd，它似乎被困在以下几行循环中：
ppoll([{fd=3, events=POLLIN}], 1, NULL, NULL, 8) = 1 ([{fd=3, revents=POLLIN}])
recvmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{"l\4\1\0019\2\0\0\32\0\0\0\216\0\0\0\1\1o\0.\0\0\0", 24}], msg_controllen=32, [{cmsg_len=28, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS, {pid=1, uid=0, gid=0}}], msg_flags=MSG_CMSG_CLOEXEC}, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) = 24
recvmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{"/org/freedesktop/systemd1/unit/h"..., 705}], msg_controllen=32, [{cmsg_len=28, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS, {pid=1, uid=0, gid=0}}], msg_flags=MSG_CMSG_CLOEXEC}, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) = 705
recvmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{"l\4\1\1\304\2\0\0\33\0\0\0\216\0\0\0\1\1o\0.\0\0\0", 24}], msg_controllen=32, [{cmsg_len=28, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS, {pid=1, uid=0, gid=0}}], msg_flags=MSG_CMSG_CLOEXEC}, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) = 24
recvmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{"/org/freedesktop/systemd1/unit/h"..., 844}], msg_controllen=32, [{cmsg_len=28, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS, {pid=1, uid=0, gid=0}}], msg_flags=MSG_CMSG_CLOEXEC}, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) = 844
recvmsg(3, 0x7ffc0948a480, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) = -1 EAGAIN (Resource temporarily unavailable)
不幸的是，我对 strace 输出没有足够的了解，无法真正了解发生了什么。有关更多详细信息，请参阅完整的 strace 输出：
execve("/bin/systemctl", ["systemctl", "start", "sshd"], [/* 19 vars */]) = 0
brk(NULL) = 0x559a0e05a000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fc77b16c000
access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=21817, ...}) = 0
mmap(NULL, 21817, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7fc77b15b000
close(3) = 0
open("/lib64/librt.so.1", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\340!\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=43776, ...}) = 0
mmap(NULL, 2128920, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7fc77ad3b000
mprotect(0x7fc77ad42000, 2093056, PROT_NONE) = 0
mmap(0x7fc77af41000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x6000) = 0x7fc77af41000
close(3) = 0
open("/lib64/libselinux.so.1", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\320i\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=155784, ...}) = 0
mmap(NULL, 2255184, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7fc77ab13000
mprotect(0x7fc77ab37000, 2093056, PROT_NONE) = 0
mmap(0x7fc77ad36000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x23000) = 0x7fc77ad36000
mmap(0x7fc77ad38000, 6480, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7fc77ad38000
close(3) = 0
open("/lib64/liblzma.so.5", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\2000\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=157424, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fc77b16b000
mmap(NULL, 2249352, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7fc77a8eb000
mprotect(0x7fc77a910000, 2093056, PROT_NONE) = 0
mmap(0x7fc77ab0f000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x24000) = 0x7fc77ab0f000
close(3) = 0
open("/lib64/liblz4.so.1", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\20%\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=85952, ...}) = 0
mmap(NULL, 2179400, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7fc77a6d3000
mprotect(0x7fc77a6e7000, 2093056, PROT_NONE) = 0
mmap(0x7fc77a8e6000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x13000) = 0x7fc77a8e6000
close(3) = 0
open("/lib64/libgcrypt.so.11", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\0u\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=535064, ...}) = 0
mmap(NULL, 2621648, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7fc77a44b000
mprotect(0x7fc77a4c8000, 2093056, PROT_NONE) = 0
mmap(0x7fc77a6c7000, 16384, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x7c000) = 0x7fc77a6c7000
mmap(0x7fc77a6cb000, 208, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7fc77a6cb000
close(3) = 0
open("/lib64/libcap.so.2", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0 \26\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=20032, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fc77b16a000
mmap(NULL, 2114112, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7fc77a243000
mprotect(0x7fc77a247000, 2093056, PROT_NONE) = 0
mmap(0x7fc77a446000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x3000) = 0x7fc77a446000
close(3) = 0
open("/lib64/libgcc_s.so.1", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\220*\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=88776, ...}) = 0
mmap(NULL, 2184192, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7fc77a02b000
mprotect(0x7fc77a040000, 2093056, PROT_NONE) = 0
mmap(0x7fc77a23f000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x14000) = 0x7fc77a23f000
close(3) = 0
open("/lib64/libpthread.so.0", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\260l\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=141968, ...}) = 0
mmap(NULL, 2208904, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7fc779e0b000
mprotect(0x7fc779e22000, 2093056, PROT_NONE) = 0
mmap(0x7fc77a021000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x16000) = 0x7fc77a021000
mmap(0x7fc77a023000, 13448, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7fc77a023000
close(3) = 0
open("/lib64/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\340$\2\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=2151672, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fc77b169000
mmap(NULL, 3981792, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7fc779a3b000
mprotect(0x7fc779bfd000, 2097152, PROT_NONE) = 0
mmap(0x7fc779dfd000, 24576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1c2000) = 0x7fc779dfd000
mmap(0x7fc779e03000, 16864, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7fc779e03000
close(3) = 0
open("/lib64/libpcre.so.1", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\360\25\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=402384, ...}) = 0
mmap(NULL, 2494984, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7fc7797d3000
mprotect(0x7fc779833000, 2097152, PROT_NONE) = 0
mmap(0x7fc779a33000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x60000) = 0x7fc779a33000
close(3) = 0
open("/lib64/libdl.so.2", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\220\r\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=19288, ...}) = 0
mmap(NULL, 2109712, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7fc7795cb000
mprotect(0x7fc7795cd000, 2097152, PROT_NONE) = 0
mmap(0x7fc7797cd000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x2000) = 0x7fc7797cd000
close(3) = 0
open("/lib64/libgpg-error.so.0", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0000\n\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=19384, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fc77b168000
mmap(NULL, 2113656, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7fc7793c3000
mprotect(0x7fc7793c7000, 2093056, PROT_NONE) = 0
mmap(0x7fc7795c6000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x3000) = 0x7fc7795c6000
close(3) = 0
open("/lib64/libattr.so.1", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\320\23\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=19896, ...}) = 0
mmap(NULL, 2113904, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7fc7791bb000
mprotect(0x7fc7791bf000, 2093056, PROT_NONE) = 0
mmap(0x7fc7793be000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x3000) = 0x7fc7793be000
close(3) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fc77b167000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fc77b163000
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fc77b161000
arch_prctl(ARCH_SET_FS, 0x7fc77b161880) = 0
mprotect(0x7fc779dfd000, 16384, PROT_READ) = 0
mprotect(0x7fc7793be000, 4096, PROT_READ) = 0
mprotect(0x7fc7795c6000, 4096, PROT_READ) = 0
mprotect(0x7fc7797cd000, 4096, PROT_READ) = 0
mprotect(0x7fc77a021000, 4096, PROT_READ) = 0
mprotect(0x7fc779a33000, 4096, PROT_READ) = 0
mprotect(0x7fc77a23f000, 4096, PROT_READ) = 0
mprotect(0x7fc77a446000, 4096, PROT_READ) = 0
mprotect(0x7fc77a6c7000, 4096, PROT_READ) = 0
mprotect(0x7fc77a8e6000, 4096, PROT_READ) = 0
mprotect(0x7fc77ab0f000, 4096, PROT_READ) = 0
mprotect(0x7fc77ad36000, 4096, PROT_READ) = 0
mprotect(0x7fc77af41000, 4096, PROT_READ) = 0
stat("/etc/sysconfig/64bit_strstr_via_64bit_strstr_sse2_unaligned", 0x7ffc0948a6b0) = -1 ENOENT (No such file or directory)
mprotect(0x559a0d333000, 20480, PROT_READ) = 0
mprotect(0x7fc77b164000, 4096, PROT_READ) = 0
munmap(0x7fc77b15b000, 21817) = 0
set_tid_address(0x7fc77b161b50) = 3189
set_robust_list(0x7fc77b161b60, 24) = 0
rt_sigaction(SIGRTMIN, {0x7fc779e11790, [], SA_RESTORER|SA_SIGINFO, 0x7fc779e1a5d0}, NULL, 8) = 0
rt_sigaction(SIGRT_1, {0x7fc779e11820, [], SA_RESTORER|SA_RESTART|SA_SIGINFO, 0x7fc779e1a5d0}, NULL, 8) = 0
rt_sigprocmask(SIG_UNBLOCK, [RTMIN RT_1], NULL, 8) = 0
getrlimit(RLIMIT_STACK, {rlim_cur=8192*1024, rlim_max=RLIM64_INFINITY}) = 0
brk(NULL) = 0x559a0e05a000
brk(0x559a0e07b000) = 0x559a0e07b000
access("/etc/system-fips", F_OK) = -1 ENOENT (No such file or directory)
statfs("/sys/fs/selinux", 0x7ffc0948b910) = -1 ENOENT (No such file or directory)
statfs("/selinux", 0x7ffc0948b910) = -1 ENOENT (No such file or directory)
open("/proc/filesystems", O_RDONLY) = 3
fstat(3, {st_mode=S_IFREG|0444, st_size=0, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fc77b160000
read(3, "nodev\tsysfs\nnodev\trootfs\nnodev\tr"..., 1024) = 309
stat("/etc/sysconfig/64bit_strstr_via_64bit_strstr_sse2_unaligned", 0x7ffc0948b4f0) = -1 ENOENT (No such file or directory)
read(3, "", 1024) = 0
close(3) = 0
munmap(0x7fc77b160000, 4096) = 0
access("/etc/selinux/config", F_OK) = 0
open("/usr/lib/locale/locale-archive", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=106075056, ...}) = 0
mmap(NULL, 106075056, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7fc772c8b000
close(3) = 0
open("/proc/self/stat", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0444, st_size=0, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fc77b160000
read(3, "3189 (systemctl) R 3187 3187 313"..., 1024) = 338
close(3) = 0
munmap(0x7fc77b160000, 4096) = 0
ioctl(1, TCGETS, {B38400 opost isig icanon echo ...}) = 0
stat("/proc/1/root", {st_mode=S_IFDIR|0555, st_size=241, ...}) = 0
stat("/", {st_mode=S_IFDIR|0555, st_size=241, ...}) = 0
stat("/proc/1/root", {st_mode=S_IFDIR|0555, st_size=241, ...}) = 0
stat("/", {st_mode=S_IFDIR|0555, st_size=241, ...}) = 0
lstat("/run/systemd/system/", {st_mode=S_IFDIR|0755, st_size=120, ...}) = 0
geteuid() = 0
socket(AF_LOCAL, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0) = 3
setsockopt(3, SOL_SOCKET, SO_PASSCRED, [1], 4) = 0
setsockopt(3, SOL_SOCKET, SO_PASSSEC, [0], 4) = 0
getsockopt(3, SOL_SOCKET, SO_RCVBUF, [212992], [4]) = 0
setsockopt(3, SOL_SOCKET, SO_RCVBUFFORCE, [8388608], 4) = 0
getsockopt(3, SOL_SOCKET, SO_SNDBUF, [212992], [4]) = 0
setsockopt(3, SOL_SOCKET, SO_SNDBUFFORCE, [8388608], 4) = 0
connect(3, {sa_family=AF_LOCAL, sun_path="/run/systemd/private"}, 22) = 0
getsockopt(3, SOL_SOCKET, SO_PEERCRED, {pid=1, uid=0, gid=0}, [12]) = 0
getsockopt(3, SOL_SOCKET, SO_PEERSEC, 0x559a0e05b810, 0x7ffc0948b5b4) = -1 ENOPROTOOPT (Protocol not available)
fstat(3, {st_mode=S_IFSOCK|0777, st_size=0, ...}) = 0
getsockopt(3, SOL_SOCKET, SO_ACCEPTCONN, [0], [4]) = 0
getsockname(3, {sa_family=AF_LOCAL, sun_path=@"00011"}, [8]) = 0
geteuid() = 0
sendmsg(3, {msg_name(0)=NULL, msg_iov(3)=[{"\0AUTH EXTERNAL ", 15}, {"30", 2}, {"\r\nNEGOTIATE_UNIX_FD\r\nBEGIN\r\n", 28}], msg_controllen=0, msg_flags=0}, MSG_DONTWAIT|MSG_NOSIGNAL) = 45
getsockopt(3, SOL_SOCKET, SO_PEERCRED, {pid=1, uid=0, gid=0}, [12]) = 0
stat("/proc/1/root", {st_mode=S_IFDIR|0555, st_size=241, ...}) = 0
stat("/", {st_mode=S_IFDIR|0555, st_size=241, ...}) = 0
ioctl(0, TCGETS, {B38400 opost isig icanon echo ...}) = 0
rt_sigprocmask(SIG_SETMASK, ~[RTMIN RT_1], [], 8) = 0
clone(child_stack=0, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0x7fc77b161b50) = 3190
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
ioctl(0, TCGETS, {B38400 opost isig icanon echo ...}) = 0
pipe2([4, 5], 0) = 0
rt_sigprocmask(SIG_SETMASK, ~[RTMIN RT_1], [], 8) = 0
clone(child_stack=0, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0x7fc77b161b50) = 3191
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
close(5) = 0
ppoll([{fd=4, events=POLLHUP}], 1, NULL, NULL, 8) = 1 ([{fd=4, revents=POLLHUP}])
close(4) = 0
gettid() = 3189
getrandom("\37I\307\354\364~\375\r\256?\323\6\350\\\313\260", 16, GRND_NONBLOCK) = 16
recvmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{"OK 2b2d83aeb02c4b349313fff193905"..., 256}], msg_controllen=32, [{cmsg_len=28, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS, {pid=1, uid=0, gid=0}}], msg_flags=MSG_CMSG_CLOEXEC}, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) = 52
sendmsg(3, {msg_name(0)=NULL, msg_iov(2)=[{"l\1\4\1 \0\0\0\1\0\0\0\240\0\0\0\1\1o\0\31\0\0\0/org/fre"..., 176}, {"\f\0\0\0sshd.service\0\0\0\0\7\0\0\0replace\0", 32}], msg_controllen=0, msg_flags=0}, MSG_DONTWAIT|MSG_NOSIGNAL) = 208
recvmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{"l\2\1\1&\0\0\0\1\0\0\0\17\0\0\0\5\1u\0\1\0\0\0", 24}], msg_controllen=32, [{cmsg_len=28, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS, {pid=1, uid=0, gid=0}}], msg_flags=MSG_CMSG_CLOEXEC}, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) = 24
recvmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{"\10\1g\0\1o\0\0!\0\0\0/org/freedesktop/sys"..., 46}], msg_controllen=32, [{cmsg_len=28, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS, {pid=1, uid=0, gid=0}}], msg_flags=MSG_CMSG_CLOEXEC}, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) = 46
sendmsg(3, {msg_name(0)=NULL, msg_iov(2)=[{"l\1\0\1\21\0\0\0\2\0\0\0\227\0\0\0\1\1o\0\31\0\0\0/org/fre"..., 168}, {"\f\0\0\0sshd.service\0", 17}], msg_controllen=0, msg_flags=0}, MSG_DONTWAIT|MSG_NOSIGNAL) = 185
recvmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{"l\4\1\1H\0\0\0\2\0\0\0\206\0\0\0\1\1o\0!\0\0\0", 24}], msg_controllen=32, [{cmsg_len=28, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS, {pid=1, uid=0, gid=0}}], msg_flags=MSG_CMSG_CLOEXEC}, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) = 24
recvmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{"/org/freedesktop/systemd1/job/21"..., 200}], msg_controllen=32, [{cmsg_len=28, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS, {pid=1, uid=0, gid=0}}], msg_flags=MSG_CMSG_CLOEXEC}, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) = 200
recvmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{"l\4\1\1D\0\0\0\3\0\0\0q\0\0\0\1\1o\0\31\0\0\0", 24}], msg_controllen=32, [{cmsg_len=28, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS, {pid=1, uid=0, gid=0}}], msg_flags=MSG_CMSG_CLOEXEC}, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) = 24
recvmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{"/org/freedesktop/systemd1\0\0\0\0\0\0\0"..., 180}], msg_controllen=32, [{cmsg_len=28, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS, {pid=1, uid=0, gid=0}}], msg_flags=MSG_CMSG_CLOEXEC}, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) = 180
recvmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{"l\4\1\1H\0\0\0\4\0\0\0\206\0\0\0\1\1o\0!\0\0\0", 24}], msg_controllen=32, [{cmsg_len=28, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS, {pid=1, uid=0, gid=0}}], msg_flags=MSG_CMSG_CLOEXEC}, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) = 24
recvmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{"/org/freedesktop/systemd1/job/19"..., 200}], msg_controllen=32, [{cmsg_len=28, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS, {pid=1, uid=0, gid=0}}], msg_flags=MSG_CMSG_CLOEXEC}, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) = 200
recvmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{"l\4\1\1M\0\0\0\5\0\0\0z\0\0\0\1\1o\0\31\0\0\0", 24}], msg_controllen=32, [{cmsg_len=28, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS, {pid=1, uid=0, gid=0}}], msg_flags=MSG_CMSG_CLOEXEC}, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) = 24
recvmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{"/org/freedesktop/systemd1\0\0\0\0\0\0\0"..., 197}], msg_controllen=32, [{cmsg_len=28, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS, {pid=1, uid=0, gid=0}}], msg_flags=MSG_CMSG_CLOEXEC}, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) = 197
recvmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{"l\2\1\0012\0\0\0\6\0\0\0\17\0\0\0\5\1u\0\2\0\0\0", 24}], msg_controllen=32, [{cmsg_len=28, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS, {pid=1, uid=0, gid=0}}], msg_flags=MSG_CMSG_CLOEXEC}, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) = 24
recvmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{"\10\1g\0\1o\0\0-\0\0\0/org/freedesktop/sys"..., 58}], msg_controllen=32, [{cmsg_len=28, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS, {pid=1, uid=0, gid=0}}], msg_flags=MSG_CMSG_CLOEXEC}, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) = 58
sendmsg(3, {msg_name(0)=NULL, msg_iov(2)=[{"l\1\0\0019\0\0\0\3\0\0\0\240\0\0\0\1\1o\0-\0\0\0/org/fre"..., 176}, {"\35\0\0\0org.freedesktop.systemd1.Uni"..., 57}], msg_controllen=0, msg_flags=0}, MSG_DONTWAIT|MSG_NOSIGNAL) = 233
recvmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{"l\2\1\1\10\0\0\0\7\0\0\0\17\0\0\0\5\1u\0\3\0\0\0", 24}], msg_controllen=32, [{cmsg_len=28, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS, {pid=1, uid=0, gid=0}}], msg_flags=MSG_CMSG_CLOEXEC}, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) = 24
recvmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{"\10\1g\0\1v\0\0\1b\0\0\0\0\0\0", 16}], msg_controllen=32, [{cmsg_len=28, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS, {pid=1, uid=0, gid=0}}], msg_flags=MSG_CMSG_CLOEXEC}, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) = 16
recvmsg(3, 0x7ffc0948a480, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) = -1 EAGAIN (Resource temporarily unavailable)
ppoll([{fd=3, events=POLLIN}], 1, NULL, NULL, 8) = 1 ([{fd=3, revents=POLLIN}])
recvmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{"l\4\1\0019\2\0\0\10\0\0\0\216\0\0\0\1\1o\0.\0\0\0", 24}], msg_controllen=32, [{cmsg_len=28, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS, {pid=1, uid=0, gid=0}}], msg_flags=MSG_CMSG_CLOEXEC}, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) = 24
recvmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{"/org/freedesktop/systemd1/unit/h"..., 705}], msg_controllen=32, [{cmsg_len=28, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS, {pid=1, uid=0, gid=0}}], msg_flags=MSG_CMSG_CLOEXEC}, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) = 705
recvmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{"l\4\1\1\304\2\0\0\t\0\0\0\216\0\0\0\1\1o\0.\0\0\0", 24}], msg_controllen=32, [{cmsg_len=28, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS, {pid=1, uid=0, gid=0}}], msg_flags=MSG_CMSG_CLOEXEC}, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) = 24
recvmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{"/org/freedesktop/systemd1/unit/h"..., 844}], msg_controllen=32, [{cmsg_len=28, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS, {pid=1, uid=0, gid=0}}], msg_flags=MSG_CMSG_CLOEXEC}, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) = 844
recvmsg(3, 0x7ffc0948a480, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) = -1 EAGAIN (Resource temporarily unavailable)
ppoll([{fd=3, events=POLLIN}], 1, NULL, NULL, 8) = 1 ([{fd=3, revents=POLLIN}])
recvmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{"l\4\1\0019\2\0\0\30\0\0\0\216\0\0\0\1\1o\0.\0\0\0", 24}], msg_controllen=32, [{cmsg_len=28, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS, {pid=1, uid=0, gid=0}}], msg_flags=MSG_CMSG_CLOEXEC}, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) = 24
recvmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{"/org/freedesktop/systemd1/unit/h"..., 705}], msg_controllen=32, [{cmsg_len=28, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS, {pid=1, uid=0, gid=0}}], msg_flags=MSG_CMSG_CLOEXEC}, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) = 705
recvmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{"l\4\1\1\304\2\0\0\31\0\0\0\216\0\0\0\1\1o\0.\0\0\0", 24}], msg_controllen=32, [{cmsg_len=28, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS, {pid=1, uid=0, gid=0}}], msg_flags=MSG_CMSG_CLOEXEC}, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) = 24
recvmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{"/org/freedesktop/systemd1/unit/h"..., 844}], msg_controllen=32, [{cmsg_len=28, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS, {pid=1, uid=0, gid=0}}], msg_flags=MSG_CMSG_CLOEXEC}, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) = 844
recvmsg(3, 0x7ffc0948a480, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) = -1 EAGAIN (Resource temporarily unavailable)
ppoll([{fd=3, events=POLLIN}], 1, NULL, NULL, 8) = 1 ([{fd=3, revents=POLLIN}])
recvmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{"l\4\1\0019\2\0\0\32\0\0\0\216\0\0\0\1\1o\0.\0\0\0", 24}], msg_controllen=32, [{cmsg_len=28, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS, {pid=1, uid=0, gid=0}}], msg_flags=MSG_CMSG_CLOEXEC}, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) = 24
recvmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{"/org/freedesktop/systemd1/unit/h"..., 705}], msg_controllen=32, [{cmsg_len=28, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS, {pid=1, uid=0, gid=0}}], msg_flags=MSG_CMSG_CLOEXEC}, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) = 705
recvmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{"l\4\1\1\304\2\0\0\33\0\0\0\216\0\0\0\1\1o\0.\0\0\0", 24}], msg_controllen=32, [{cmsg_len=28, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS, {pid=1, uid=0, gid=0}}], msg_flags=MSG_CMSG_CLOEXEC}, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) = 24
recvmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{"/org/freedesktop/systemd1/unit/h"..., 844}], msg_controllen=32, [{cmsg_len=28, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS, {pid=1, uid=0, gid=0}}], msg_flags=MSG_CMSG_CLOEXEC}, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) = 844
recvmsg(3, 0x7ffc0948a480, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) = -1 EAGAIN (Resource temporarily unavailable)
ppoll([{fd=3, events=POLLIN}], 1, NULL, NULL, 8) = ? ERESTARTNOHAND (To be restarted if no handler)
--- SIGINT {si_signo=SIGINT, si_code=SI_KERNEL} ---
+++ killed by SIGINT +++
非常感谢任何帮助，我很乐意提供任何必要的更多细节。
编辑：
/usr/lib/systemd/system/sshd.service包含以下内容：
[Unit]
Description=OpenSSH server daemon
Documentation=man:sshd(8) man:sshd_config(5)
After=network.target sshd-keygen.service
Wants=sshd-keygen.service
[Service]
Type=notify
EnvironmentFile=/etc/sysconfig/sshd
ExecStart=/usr/sbin/sshd $OPTIONS
ExecReload=/bin/kill -HUP $MAINPID
KillMode=process
Restart=on-failure
RestartSec=42s
[Install]
WantedBy=multi-user.target