Estou realmente lutando para chegar ao fim de
Por alguma razão, o cron não pode ver um sistema de arquivos montado manualmente. Este é um drive USB formatado para ext4 montado em /backup . Para completar, montei-o enquanto estava conectado ao SSH, não diretamente em um terminal.
Se eu comparar a digitação mount | sort na linha de comando (por ssh) com o mesmo comando sobre cron ou atd , a versão do cron perderá as linhas:
tmpfs on /run/sshd type tmpfs (rw,nosuid,nodev,mode=755)
/dev/sdb1 on /backup type ext4 (rw,relatime,data=ordered)
Confirmei que nem o cron nem o sshd são chroot ed usando a resposta aceita para outra pergunta .
Se nenhum dos dois estiver chrooted, o que mais pode fazer com que dois processos diferentes vejam montagens diferentes?
Isso está realmente causando um problema porque meus backups continuam gravando no cartão SD de 30 GB no meu r-pi em vez do disco rígido USB de 2 TB.
Editar para referência futura. Esse bug no Systemd v236 parece a causa. link
Se eu digitar
mount | sort
Eu obtenho
/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)
Mas quando eu executo isso com cron ou atd , obtenho:
/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)
Parece que os daemons estão sendo executados em namespaces de montagem diferentes, portanto, as alterações feitas em sua sessão SSH não são visíveis em cron ou at jobs. Veja mountinfo e ns/mnt nos vários diretórios /proc/${pid} dos deamons para verificar quais namespaces eles estão usando e o que eles podem herdar.