I just restored my Raspberry Pi server from an
rsync image. During the backup, I had excluded
/var/cache/*, thinking that this would restore an empty directory. This worked, but when I rebooted, a process complained that it couldn't write to it in the following mail.
Subject: status report from ddclient@raspberrypi ... WARNING: updating <url>.dynu.com: nochg: No update required; unnecessary attempts to change to the current address are considered abusive FATAL: Cannot create file '/var/cache/ddclient/ddclient.cache'. (No such file or directory)
I checked the permissions of
/var/log, which were consistent with my Arch desktop system.
$ ls -ld /var/cache/ drwxr-xr-x 3 root root 4096 Aug 15 13:23 /var/cache/
Do I have to do anything else? If the permissions are
a-w, then how can non-root processes write in here?