Back In Time is set up to start backups daily as soon as the external disk got connected.This results in a udev rule which starts anacron with a config file generated by Back In Time. Unfortunately the backups do not run, as anacron always throws an error anacron: Can't open timestamp file for job 1_Main_profile: Read-only file system (seen in syslog).The command which Back In Time generated as udev rule runs fine, if started manually (started as root user and as the ordinary user jdoe). (Also the backup runs fine when started manually via GUI.)I would be happy to find at least out which file exactly anacron can not open, and of course why.udev rule:ACTION==add, ENV{ID_FS_UUID}==dd68d7f7-054b-dae0-a4a2-4315acad138a, RUN+=/bin/su - 'jdoe' -c 'test -x /usr/sbin/anacron && test -e /home/jdoe/.config/backintime/anacrontab-dd68d7f7-054b-dae0-a4a2-4315acad138a && /usr/sbin/anacron -s -t /home/jdoe/.config/backintime/anacrontab-dd68d7f7-054b-dae0-a4a2-4315acad138a -S /home/jdoe/.local/share/backintime/anacron' &anacrontab, modified for now to do just logging, original file (without logger   ||) did start backup fine when executed manually, but not automatically:$ cat /home/jdoe/.config/backintime/anacrontab-dd68d7f7-dae0-4315-a4a2-054bacad138aSHELL=/bin/bashPATH=/home/jdoe/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/gamesDISPLAY=:0.01   0   1_Main_profile  /usr/bin/logger would start backup now, but exiting, as you set in anacrontab :-) || /usr/bin/nice -n 19 /usr/bin/ionice -c2 -n7 /usr/bin/backintime --backup-job >/dev/null 2>&1files/folders (rights of '1_Main_profile' get set like this by running anacron command out of udev rule):$ ls -ld /home/jdoe/.local/share/backintime/anacron/drwxrwxrwx 2 jdoe jdoe 4096 Jul 18 10:41 /home/jdoe/.local/share/backintime/anacron/$ ls -l /home/jdoe/.local/share/backintime/anacron/insgesamt 8-rw------- 1 jdoe jdoe 9 Jul 18 10:42 1_Main_profile$ groups jdoejdoe : jdoe adm cdrom sudo dip plugdev lpadmin sambashare vboxusers$ ls -ld /var/spool/anacron/drwxrwxr-x 2 root adm 4096 Apr 30  2016 /var/spool/anacron/$ ls -l /var/spool/anacron/insgesamt 12-rw------- 1 root root 9 Jul 18 10:20 cron.daily-rw------- 1 root root 9 Jun 29 09:07 cron.monthly-rw------- 1 root root 9 Jul 18 10:24 cron.weeklyStarting command out of udev rule manually (as root via ssh, starting it without the logger  || from above will start backup):$ /bin/su - 'jdoe' -c 'strace /usr/sbin/anacron -s -t /home/jdoe/.config/backintime/anacrontab-dd68d7f7-054b-dae0-a4a2-4315acad138a -S /home/jdoe/.local/share/backintime/anacron &> /dev/shm/strace-anacron-backintime'X11 connection rejected because of wrong authentication.$ cat /dev/shm/strace-anacron-backintimeexecve(/usr/sbin/anacron, [/usr/sbin/anacron, -s, -t, /home/jdoe/.config/backintime/..., -S, /home/jdoe/.local/share/backin...], [/* 26 vars */]) = 0brk(NULL)                               = 0x562556b3c000access(/etc/ld.so.nohwcap, F_OK)      = -1 ENOENT (No such file or directory)mmap(NULL, 12288, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f75287a6000access(/etc/ld.so.preload, R_OK)      = -1 ENOENT (No such file or directory)open(/etc/ld.so.cache, O_RDONLY|O_CLOEXEC) = 3fstat(3, {st_mode=S_IFREG|0644, st_size=178056, ...}) = 0mmap(NULL, 178056, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f752877a000close(3)                                = 0access(/etc/ld.so.nohwcap, F_OK)      = -1 ENOENT (No such file or directory)open(/lib/x86_64-linux-gnu/libc.so.6, O_RDONLY|O_CLOEXEC) = 3read(3, \177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\320\3\2\0\0\0\0\0..., 832) = 832fstat(3, {st_mode=S_IFREG|0755, st_size=1685264, ...}) = 0mmap(NULL, 3791264, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f75281e8000mprotect(0x7f752837d000, 2093056, PROT_NONE) = 0mmap(0x7f752857c000, 24576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x194000) = 0x7f752857c000mmap(0x7f7528582000, 14752, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f7528582000close(3)                                = 0mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f7528778000arch_prctl(ARCH_SET_FS, 0x7f7528778700) = 0mprotect(0x7f752857c000, 16384, PROT_READ) = 0mprotect(0x5625560cc000, 4096, PROT_READ) = 0mprotect(0x7f75287a9000, 4096, PROT_READ) = 0munmap(0x7f752877a000, 178056)          = 0brk(NULL)                               = 0x562556b3c000brk(0x562556b5d000)                     = 0x562556b5d000open(/usr/lib/locale/locale-archive, O_RDONLY|O_CLOEXEC) = 3fstat(3, {st_mode=S_IFREG|0644, st_size=3259968, ...}) = 0mmap(NULL, 3259968, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f7527ecc000close(3)                                = 0open(./, O_RDONLY)                    = 3chdir(/home/jdoe/.local/share/backintime/anacron) = 0umask(000)                              = 022rt_sigprocmask(SIG_BLOCK, NULL, [], 8)  = 0close(0)                                = 0open(/dev/null, O_RDONLY)             = 0close(1)                                = 0open(/dev/null, O_WRONLY)             = 1close(2)                                = 0open(/dev/null, O_WRONLY)             = 2clone(child_stack=NULL, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0x7f75287789d0) = 4473exit_group(0)                           = ?+++ exited with 0 +++
Back In Time backup not starting via anacron because of Can't open timestamp file for job
backintime;anacron