서로 다른 프로세스가 서로 다른 마운트 지점을 보게 되는 원인은 무엇입니까?

알아내기가 정말 어렵네요이것.

어떤 이유로 cron이 수동으로 마운트한 파일 시스템을 볼 수 없습니다. 이것은 ext4로 포맷되어 에 설치되었습니다 /backup. 완성도를 높이기 위해 터미널에서 직접 설치하지 않고 SSH에 로그인한 상태에서 설치했습니다.

mount | sortSSH를 통해 명령줄에 입력한 내용을 동일한 명령과 비교 cron하면 cron atd버전에서 다음 줄을 놓칠 수 있습니다.

tmpfs on /run/sshd type tmpfs (rw,nosuid,nodev,mode=755)
/dev/sdb1 on /backup type ext4 (rw,relatime,data=ordered)

chrootcron과 sshd가 모두 사용 되지 않는 것을 확인했습니다.다른 질문에 대한 답변.

둘 다 루트가 변경되지 않은 경우 두 개의 서로 다른 프로세스가 서로 다른 설치를 보게 만드는 또 다른 원인은 무엇입니까?

내 백업이 2TB USB 하드 드라이브 대신 r-pi의 30GB SD 카드에 지속적으로 기록되므로 문제가 발생합니다.

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편집하다나중에 참고할 수 있도록. Systemd v236의 이 버그가 원인인 것 같습니다. https://github.com/systemd/systemd/issues/7761

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내가 들어가면

mount | sort

알겠어요

/dev/mmcblk0p1 on /boot type vfat (rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=ascii,shortname=mixed,errors=remount-ro)
/dev/mmcblk0p2 on / type ext4 (rw,noatime,data=ordered)
/dev/sda1 on /home type ext4 (rw,relatime,data=ordered)
/dev/sda1 on /mnt/mercury_data type ext4 (rw,relatime,data=ordered)
/dev/sda1 on /root type ext4 (rw,relatime,data=ordered)
/dev/sda1 on /var type ext4 (rw,relatime,data=ordered)
/dev/sdb1 on /backup type ext4 (rw,relatime,data=ordered)
cgroup on /sys/fs/cgroup/blkio type cgroup (rw,nosuid,nodev,noexec,relatime,blkio)
cgroup on /sys/fs/cgroup/cpu,cpuacct type cgroup (rw,nosuid,nodev,noexec,relatime,cpu,cpuacct)
cgroup on /sys/fs/cgroup/cpuset type cgroup (rw,nosuid,nodev,noexec,relatime,cpuset)
cgroup on /sys/fs/cgroup/devices type cgroup (rw,nosuid,nodev,noexec,relatime,devices)
cgroup on /sys/fs/cgroup/freezer type cgroup (rw,nosuid,nodev,noexec,relatime,freezer)
cgroup on /sys/fs/cgroup/net_cls type cgroup (rw,nosuid,nodev,noexec,relatime,net_cls)
cgroup on /sys/fs/cgroup/systemd type cgroup (rw,nosuid,nodev,noexec,relatime,xattr,name=systemd)
cgroup on /sys/fs/cgroup/unified type cgroup2 (rw,nosuid,nodev,noexec,relatime)
configfs on /sys/kernel/config type configfs (rw,relatime)
debugfs on /sys/kernel/debug type debugfs (rw,relatime)
devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000)
devtmpfs on /dev type devtmpfs (rw,relatime,size=470180k,nr_inodes=117545,mode=755)
mqueue on /dev/mqueue type mqueue (rw,relatime)
proc on /proc type proc (rw,relatime)
sunrpc on /run/rpc_pipefs type rpc_pipefs (rw,relatime)
sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime)
systemd-1 on /proc/sys/fs/binfmt_misc type autofs (rw,relatime,fd=27,pgrp=1,timeout=0,minproto=5,maxproto=5,direct)
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev)
tmpfs on /run type tmpfs (rw,nosuid,nodev,mode=755)
tmpfs on /run/lock type tmpfs (rw,nosuid,nodev,noexec,relatime,size=5120k)
tmpfs on /run/sshd type tmpfs (rw,nosuid,nodev,mode=755)
tmpfs on /sys/fs/cgroup type tmpfs (ro,nosuid,nodev,noexec,mode=755)

하지만 이것을 실행하면 cron다음과 같은 atd결과를 얻습니다.

/dev/mmcblk0p1 on /boot type vfat (rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=ascii,shortname=mixed,errors=remount-ro)
/dev/mmcblk0p2 on / type ext4 (rw,noatime,data=ordered)
/dev/sda1 on /home type ext4 (rw,relatime,data=ordered)
/dev/sda1 on /mnt/mercury_data type ext4 (rw,relatime,data=ordered)
/dev/sda1 on /root type ext4 (rw,relatime,data=ordered)
/dev/sda1 on /var type ext4 (rw,relatime,data=ordered)
cgroup on /sys/fs/cgroup/blkio type cgroup (rw,nosuid,nodev,noexec,relatime,blkio)
cgroup on /sys/fs/cgroup/cpu,cpuacct type cgroup (rw,nosuid,nodev,noexec,relatime,cpu,cpuacct)
cgroup on /sys/fs/cgroup/cpuset type cgroup (rw,nosuid,nodev,noexec,relatime,cpuset)
cgroup on /sys/fs/cgroup/devices type cgroup (rw,nosuid,nodev,noexec,relatime,devices)
cgroup on /sys/fs/cgroup/freezer type cgroup (rw,nosuid,nodev,noexec,relatime,freezer)
cgroup on /sys/fs/cgroup/net_cls type cgroup (rw,nosuid,nodev,noexec,relatime,net_cls)
cgroup on /sys/fs/cgroup/systemd type cgroup (rw,nosuid,nodev,noexec,relatime,xattr,name=systemd)
cgroup on /sys/fs/cgroup/unified type cgroup2 (rw,nosuid,nodev,noexec,relatime)
configfs on /sys/kernel/config type configfs (rw,relatime)
debugfs on /sys/kernel/debug type debugfs (rw,relatime)
devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000)
devtmpfs on /dev type devtmpfs (rw,relatime,size=470180k,nr_inodes=117545,mode=755)
mqueue on /dev/mqueue type mqueue (rw,relatime)
proc on /proc type proc (rw,relatime)
sunrpc on /run/rpc_pipefs type rpc_pipefs (rw,relatime)
sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime)
systemd-1 on /proc/sys/fs/binfmt_misc type autofs (rw,relatime,fd=27,pgrp=1,timeout=0,minproto=5,maxproto=5,direct)
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev)
tmpfs on /run type tmpfs (rw,nosuid,nodev,mode=755)
tmpfs on /run/lock type tmpfs (rw,nosuid,nodev,noexec,relatime,size=5120k)
tmpfs on /sys/fs/cgroup type tmpfs (ro,nosuid,nodev,noexec,mode=755)