df无法返回任何输出，只是挂起。一年多来没有发生任何变化fstab。没有网络驱动器。
操作系统：CentOS 7.0
输出strace df：
execve("/usr/bin/df", ["df"], [/* 22 vars */]) = 0
brk(NULL) = 0x1499000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f628668f000
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=45250, ...}) = 0
mmap(NULL, 45250, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f6286683000
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\0P%\2\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=2173512, ...}) = 0
mmap(NULL, 3981792, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f62860a2000
mprotect(0x7f6286265000, 2093056, PROT_NONE) = 0
mmap(0x7f6286464000, 24576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1c2000) = 0x7f6286464000
mmap(0x7f628646a000, 16864, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f628646a000
close(3) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f6286682000
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f6286680000
arch_prctl(ARCH_SET_FS, 0x7f6286680740) = 0
mprotect(0x7f6286464000, 16384, PROT_READ) = 0
mprotect(0x616000, 4096, PROT_READ) = 0
mprotect(0x7f6286690000, 4096, PROT_READ) = 0
munmap(0x7f6286683000, 45250) = 0
brk(NULL) = 0x1499000
brk(0x14ba000) = 0x14ba000
brk(NULL) = 0x14ba000
open("/usr/lib/locale/locale-archive", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=106070960, ...}) = 0
mmap(NULL, 106070960, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f627fb79000
close(3) = 0
open("/usr/share/locale/locale.alias", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=2502, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f628668e000
read(3, "# Locale name alias data base.\n#"..., 4096) = 2502
read(3, "", 4096) = 0
close(3) = 0
munmap(0x7f628668e000, 4096) = 0
open("/usr/share/locale/en_US.UTF-8/LC_MESSAGES/coreutils.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/usr/share/locale/en_US.utf8/LC_MESSAGES/coreutils.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/usr/share/locale/en_US/LC_MESSAGES/coreutils.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/usr/share/locale/en.UTF-8/LC_MESSAGES/coreutils.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/usr/share/locale/en.utf8/LC_MESSAGES/coreutils.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/usr/share/locale/en/LC_MESSAGES/coreutils.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/etc/mtab", 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) = 0x7f628668e000
read(3, "rootfs / rootfs rw 0 0\nsysfs /sy"..., 1024) = 1024
read(3, "oexec,relatime,memory 0 0\ncgroup"..., 1024) = 1024
read(3, "rw,nosuid,nodev,relatime,size=14"..., 1024) = 167
read(3, "", 1024) = 0
close(3) = 0
munmap(0x7f628668e000, 4096) = 0
stat("/", {st_mode=S_IFDIR|0555, st_size=4096, ...}) = 0
stat("/sys", {st_mode=S_IFDIR|0555, st_size=0, ...}) = 0
stat("/proc", {st_mode=S_IFDIR|0555, st_size=0, ...}) = 0
stat("/dev", {st_mode=S_IFDIR|0755, st_size=2780, ...}) = 0
stat("/sys/kernel/security", {st_mode=S_IFDIR|0755, st_size=0, ...}) = 0
stat("/dev/shm", {st_mode=S_IFDIR|S_ISVTX|0777, st_size=40, ...}) = 0
stat("/dev/pts", {st_mode=S_IFDIR|0755, st_size=0, ...}) = 0
stat("/run", {st_mode=S_IFDIR|0755, st_size=1100, ...}) = 0
stat("/sys/fs/cgroup", {st_mode=S_IFDIR|0755, st_size=340, ...}) = 0
stat("/sys/fs/cgroup/systemd", {st_mode=S_IFDIR|0755, st_size=0, ...}) = 0
stat("/sys/fs/pstore", {st_mode=S_IFDIR|0755, st_size=0, ...}) = 0
stat("/sys/fs/cgroup/devices", {st_mode=S_IFDIR|0755, st_size=0, ...}) = 0
stat("/sys/fs/cgroup/pids", {st_mode=S_IFDIR|0755, st_size=0, ...}) = 0
stat("/sys/fs/cgroup/cpu,cpuacct", {st_mode=S_IFDIR|0755, st_size=0, ...}) = 0
stat("/sys/fs/cgroup/memory", {st_mode=S_IFDIR|0755, st_size=0, ...}) = 0
stat("/sys/fs/cgroup/hugetlb", {st_mode=S_IFDIR|0755, st_size=0, ...}) = 0
stat("/sys/fs/cgroup/freezer", {st_mode=S_IFDIR|0755, st_size=0, ...}) = 0
stat("/sys/fs/cgroup/blkio", {st_mode=S_IFDIR|0755, st_size=0, ...}) = 0
stat("/sys/fs/cgroup/perf_event", {st_mode=S_IFDIR|0755, st_size=0, ...}) = 0
stat("/sys/fs/cgroup/cpuset", {st_mode=S_IFDIR|0755, st_size=0, ...}) = 0
stat("/sys/fs/cgroup/net_cls,net_prio", {st_mode=S_IFDIR|0755, st_size=0, ...}) = 0
stat("/sys/kernel/config", {st_mode=S_IFDIR|0755, st_size=0, ...}) = 0
stat("/", {st_mode=S_IFDIR|0555, st_size=4096, ...}) = 0
stat("/proc/sys/fs/binfmt_misc",
fstab：
/dev/xvda1 / ext4 defaults,noatime 1 1
/swapfile swap swap sw 0 0
答案1
升级到 7.5 后，一些服务器开始出现此问题。快速重启可以修复此问题，但我无法承受重启生产主机的代价，经过数小时的故障排除后，问题终于解决了。
systemctl restart proc-sys-fs-binfmt_misc.mount
答案2
我在许多服务器上都遇到了同样的问题
快速而肮脏的解决方法是
yum -y reinstall systemd
答案3
解决方案很奇怪。出现了一个新问题，即某些网络路由无法解析。研究发现，底层主机强制更新路由表，更新内核。实际上，通过重新启动并重新输入正确的路由表解决了该问题。