CentOS 7: df começou a travar

dffalha ao retornar qualquer saída e apenas trava. Não houve alterações fstabem mais de um ano. Não há unidades de rede.

SO: CentOS 7.0

Saída de 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

Começou a ter esse problema em alguns servidores após a atualização da versão 7.5. Uma reinicialização rápida corrigirá o problema, mas eu não podia me dar ao luxo de reiniciar os hosts de produção, após várias horas de solução de problemas a seguir.

systemctl restart proc-sys-fs-binfmt_misc.mount

Eu tenho o mesmo problema em muitos servidores

correção rápida e suja é

yum -y reinstall systemd

A solução acabou sendo estranha. Um novo problema se manifestou na forma de certas rotas de rede que não foram resolvidas. Na pesquisa, foi descoberto que a força do host subjacente atualizava as tabelas de roteamento, atualizando o kernel. Efetivamente, o problema foi resolvido com uma reinicialização e reinserção das tabelas de roteamento corretas.