Default Pi-Image: read-only database

I looked up the ownerships as mentioned here:

and they seem correct:

$ stat -c "%U:%G %a %n" /etc/pihole/* | column -t
root:root      644  /etc/pihole/adlists.list
root:root      644  /etc/pihole/adlists.list.old
root:root      644  /etc/pihole/custom.list
pihole:pihole  644  /etc/pihole/dhcp.leases
root:root      644  /etc/pihole/dns-servers.conf
pihole:pihole  664  /etc/pihole/gravity.db
pihole:pihole  664  /etc/pihole/gravity_old.db
root:root      644  /etc/pihole/install.log
root:root      644  /etc/pihole/list.10.v.firebog.net.domains
root:root      644  /etc/pihole/list.10.v.firebog.net.domains.sha1
root:root      644  /etc/pihole/list.11.pgl.yoyo.org.domains
root:root      644  /etc/pihole/list.11.pgl.yoyo.org.domains.sha1
root:root      644  /etc/pihole/list.13.raw.githubusercontent.com.domains
root:root      644  /etc/pihole/list.13.raw.githubusercontent.com.domains.sha1
root:root      644  /etc/pihole/list.14.raw.githubusercontent.com.domains
root:root      644  /etc/pihole/list.14.raw.githubusercontent.com.domains.sha1
root:root      644  /etc/pihole/list.15.www.technoy.de.domains
root:root      644  /etc/pihole/list.15.www.technoy.de.domains.sha1
root:root      644  /etc/pihole/list.16.raw.githubusercontent.com.domains
root:root      644  /etc/pihole/list.16.raw.githubusercontent.com.domains.sha1
root:root      644  /etc/pihole/list.17.www.technoy.de.domains
root:root      644  /etc/pihole/list.17.www.technoy.de.domains.sha1
root:root      644  /etc/pihole/list.18.www.technoy.de.domains
root:root      644  /etc/pihole/list.18.www.technoy.de.domains.sha1
root:root      644  /etc/pihole/list.19.raw.githubusercontent.com.domains
root:root      644  /etc/pihole/list.19.raw.githubusercontent.com.domains.sha1
root:root      644  /etc/pihole/list.1.raw.githubusercontent.com.domains
root:root      644  /etc/pihole/list.1.raw.githubusercontent.com.domains.sha1
root:root      644  /etc/pihole/list.20.raw.githubusercontent.com.domains
root:root      644  /etc/pihole/list.20.raw.githubusercontent.com.domains.sha1
root:root      644  /etc/pihole/list.21.someonewhocares.org.domains
root:root      644  /etc/pihole/list.21.someonewhocares.org.domains.sha1
root:root      644  /etc/pihole/list.2.raw.githubusercontent.com.domains
root:root      644  /etc/pihole/list.2.raw.githubusercontent.com.domains.sha1
root:root      644  /etc/pihole/list.3.raw.githubusercontent.com.domains
root:root      644  /etc/pihole/list.3.raw.githubusercontent.com.domains.sha1
root:root      644  /etc/pihole/list.4.v.firebog.net.domains
root:root      644  /etc/pihole/list.4.v.firebog.net.domains.sha1
root:root      644  /etc/pihole/list.5.adaway.org.domains
root:root      644  /etc/pihole/list.5.adaway.org.domains.sha1
root:root      644  /etc/pihole/list.6.v.firebog.net.domains
root:root      644  /etc/pihole/list.6.v.firebog.net.domains.sha1
root:root      644  /etc/pihole/list.7.v.firebog.net.domains
root:root      644  /etc/pihole/list.7.v.firebog.net.domains.sha1
root:root      644  /etc/pihole/list.8.raw.githubusercontent.com.domains
root:root      644  /etc/pihole/list.8.raw.githubusercontent.com.domains.sha1
root:root      644  /etc/pihole/list.9.s3.amazonaws.com.domains
root:root      644  /etc/pihole/list.9.s3.amazonaws.com.domains.sha1
root:root      644  /etc/pihole/local.list
root:root      644  /etc/pihole/logrotate
pihole:pihole  644  /etc/pihole/macvendor.db
root:root      755  /etc/pihole/migration_backup
pihole:root    664  /etc/pihole/pihole-FTL.conf
pihole:pihole  664  /etc/pihole/pihole-FTL.db
root:root      644  /etc/pihole/setupVars.conf
root:root      644  /etc/pihole/versions