Всем привет!
Вопрос из любопытства. Вот значит включил я OverlayFS в МалинкеПи3Б и обнаружил любопытную особенность монтирования, нет папок upper и work. А как это? Выглядит всё вот так:
root@rasp:/home/pi # mount
sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime)
proc on /proc type proc (rw,relatime)
udev on /dev type devtmpfs (rw,nosuid,relatime,size=243284k,nr_inodes=60821,mode=755)
devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000)
tmpfs on /run type tmpfs (rw,nosuid,noexec,relatime,size=76332k,mode=755)
overlay on / type overlay (rw,noatime,lowerdir=/lower,upperdir=/upper/data,workdir=/upper/work)
securityfs on /sys/kernel/security type securityfs (rw,nosuid,nodev,noexec,relatime)
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev)
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)
cgroup2 on /sys/fs/cgroup/unified type cgroup2 (rw,nosuid,nodev,noexec,relatime,nsdelegate)
cgroup on /sys/fs/cgroup/systemd type cgroup (rw,nosuid,nodev,noexec,relatime,xattr,name=systemd)
none on /sys/fs/bpf type bpf (rw,nosuid,nodev,noexec,relatime,mode=700)
cgroup on /sys/fs/cgroup/blkio type cgroup (rw,nosuid,nodev,noexec,relatime,blkio)
cgroup on /sys/fs/cgroup/net_cls,net_prio type cgroup (rw,nosuid,nodev,noexec,relatime,net_cls,net_prio)
cgroup on /sys/fs/cgroup/cpuset type cgroup (rw,nosuid,nodev,noexec,relatime,cpuset)
cgroup on /sys/fs/cgroup/cpu,cpuacct type cgroup (rw,nosuid,nodev,noexec,relatime,cpu,cpuacct)
cgroup on /sys/fs/cgroup/devices type cgroup (rw,nosuid,nodev,noexec,relatime,devices)
cgroup on /sys/fs/cgroup/perf_event type cgroup (rw,nosuid,nodev,noexec,relatime,perf_event)
cgroup on /sys/fs/cgroup/pids type cgroup (rw,nosuid,nodev,noexec,relatime,pids)
cgroup on /sys/fs/cgroup/freezer type cgroup (rw,nosuid,nodev,noexec,relatime,freezer)
systemd-1 on /proc/sys/fs/binfmt_misc type autofs (rw,relatime,fd=32,pgrp=1,timeout=0,minproto=5,maxproto=5,direct)
debugfs on /sys/kernel/debug type debugfs (rw,relatime)
mqueue on /dev/mqueue type mqueue (rw,relatime)
configfs on /sys/kernel/config type configfs (rw,relatime)
/dev/mmcblk0p1 on /boot type vfat (rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=ascii,shortname=mixed,errors=remount-ro)
tmpfs on /run/user/1000 type tmpfs (rw,nosuid,nodev,relatime,size=76328k,mode=700,uid=1000,gid=1000)
binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw,relatime)
tracefs on /sys/kernel/debug/tracing type tracefs (rw,relatime)
можно видеть, что / (root) монтирован в overlay, где в скобочках видно lowerdir=/lower,upperdir=/upper/data,workdir=/upper/work
но если сделать так:
root@rasp:/ # ls -la /
total 36
drwxr-xr-x 1 root root 160 Jan 1 1970 .
drwxr-xr-x 1 root root 160 Jan 1 1970 ..
lrwxrwxrwx 1 root root 7 Jan 11 18:50 bin -> usr/bin
drwxr-xr-x 4 root root 4096 Jan 1 1970 boot
drwxr-xr-x 17 root root 3720 Jul 6 12:49 dev
drwxr-xr-x 1 root root 120 Jul 6 16:15 etc
drwxr-xr-x 1 root root 60 Jan 11 18:52 home
lrwxrwxrwx 1 root root 7 Jan 11 18:50 lib -> usr/lib
drwx------ 2 root root 16384 Jan 11 19:08 lost+found
drwxr-xr-x 2 root root 4096 Jan 11 18:50 media
drwxr-xr-x 2 root root 4096 Jan 11 18:50 mnt
drwxr-xr-x 3 root root 4096 Jan 11 18:52 opt
dr-xr-xr-x 194 root root 0 Jan 1 1970 proc
drwx------ 1 root root 120 Jul 6 16:19 root
drwxr-xr-x 20 root root 700 Jul 6 17:38 run
lrwxrwxrwx 1 root root 8 Jan 11 18:50 sbin -> usr/sbin
drwxr-xr-x 2 root root 4096 Jan 11 18:50 srv
dr-xr-xr-x 12 root root 0 Jan 1 1970 sys
drwxrwxrwt 1 root root 340 Jul 6 17:17 tmp
drwxr-xr-x 1 root root 100 Jan 11 18:50 usr
drwxr-xr-x 1 root root 140 Feb 12 21:19 var
то папки /lower или /upper тут нет. А где они?! А как это?