Unable to Switch Back to 'rpi-ro'

General support for the Pi-Star System
G4FDL
Posts: 44
Joined: Wed Apr 11, 2018 12:10 pm

Re: Unable to Switch Back to 'rpi-ro'

Post by G4FDL »

That shows that dhclient needs the file system to be rw so it can write to /var/lib/dhcp/dhclient.leases

kill dhclient then try rpi-ro
AF6VN
Posts: 821
Joined: Fri Jul 20, 2018 1:15 am

Re: Unable to Switch Back to 'rpi-ro'

Post by AF6VN »

KN2TOD wrote: Sun Jun 05, 2022 8:57 pm FWIW:

Happened to try out DHCLIENT recently. It appears it can/will inadvertently put the system in permanent RW mode:

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pi-star@pi-star(ro):~$ sudo dhclient -v

can't create /var/lib/dhcp/dhclient.leases: Read-only file system

pi-star@pi-star(rw):~$ 
ummmm.... I wonder what it's up to.
Just an FYI: but a regular Pi=Star install has...

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pi-star@pi-star-3b(ro):~$ df
Filesystem     1K-blocks    Used Available Use% Mounted on
/dev/root       15213412 1850688  12709040  13% /
devtmpfs          464768       0    464768   0% /dev
tmpfs             498048       0    498048   0% /dev/shm
tmpfs              32768    7632     25136  24% /run
tmpfs               5120       0      5120   0% /run/lock
tmpfs              32768       0     32768   0% /sys/fs/cgroup
tmpfs                 16       4        12  25% /var/lib/logrotate
tmpfs              65536       8     65528   1% /tmp
tmpfs                 16       0        16   0% /var/lib/sudo
tmpfs              65536    7896     57640  13% /var/log
tmpfs               1024      72       952   8% /var/cache/samba
tmpfs               1024       0      1024   0% /var/lib/nginx/body
tmpfs                 64       0        64   0% /var/lib/php/sessions
tmpfs               4096    2176      1920  54% /var/lib/samba/private
tmpfs                 32      16        16  50% /var/lib/dhcpcd5              <<<=============
/dev/mmcblk0p1     64456   51032     13424  80% /boot
tmpfs              99608       0     99608   0% /run/user/1000
pi-star@pi-star-3b(ro):~$
... mounted in a tmpfs (aka RAM disk).

Find out where that mount is made, and add a line referencing /var/lib/dhcp may clear up your experiment. (I think it's /etc/fstab, but /etc/mtab has some stuff too -- but may be a dynamic file updated by the mount command using fstab)

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pi-star@pi-star-3b(ro):~$ cat /etc/fstab
#File System            Mountpoint              Type    Options                                         Dump    Pass
proc                    /proc                   proc    defaults                                        0       0
/dev/mmcblk0p1          /boot                   vfat    defaults,ro                                     0       2
/dev/mmcblk0p2          /                       ext4    defaults,noatime,ro                             0       1
# a swapfile is not a swap partition, no line here
#   use  dphys-swapfile swap[on|off]  for that
tmpfs                   /run                    tmpfs   nodev,noatime,nosuid,mode=1777,size=32m         0       0
tmpfs                   /run/lock               tmpfs   nodev,noatime,nosuid,mode=1777,size=5m          0       0
tmpfs                   /sys/fs/cgroup          tmpfs   nodev,noatime,nosuid,mode=1755,size=32m         0       0
tmpfs                   /tmp                    tmpfs   nodev,noatime,nosuid,mode=1777,size=64m         0       0
tmpfs                   /var/log                tmpfs   nodev,noatime,nosuid,mode=0755,size=64m         0       0
tmpfs                   /var/lib/sudo           tmpfs   nodev,noatime,nosuid,mode=1777,size=16k         0       0
tmpfs                   /var/lib/dhcpcd5        tmpfs   nodev,noatime,nosuid,mode=1777,size=32k         0       0
tmpfs                   /var/lib/logrotate      tmpfs   nodev,noatime,nosuid,mode=0755,size=16k         0       0
tmpfs                   /var/lib/nginx/body     tmpfs   nodev,noatime,nosuid,mode=1700,size=1m          0       0
tmpfs                   /var/lib/php/sessions   tmpfs   nodev,noatime,nosuid,mode=0777,size=64k         0       0
tmpfs                   /var/lib/samba/private  tmpfs   nodev,noatime,nosuid,mode=0755,size=4m          0       0
tmpfs                   /var/cache/samba        tmpfs   nodev,noatime,nosuid,mode=0755,size=1m          0       0
pi-star@pi-star-3b(ro):~$

--
AF6VN
Dennis L Bieber
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