For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/server:database/openSUSE_Tumbleweed/server:database.repo
zypper refresh
zypper install rrdtool-cached
For openSUSE Factory zSystems run the following as root:
zypper addrepo https://download.opensuse.org/repositories/server:database/openSUSE_Factory_zSystems/server:database.repo
zypper refresh
zypper install rrdtool-cached
For openSUSE Factory PowerPC run the following as root:
zypper addrepo https://download.opensuse.org/repositories/server:database/openSUSE_Factory_PowerPC/server:database.repo
zypper refresh
zypper install rrdtool-cached
For openSUSE Factory ARM run the following as root:
zypper addrepo https://download.opensuse.org/repositories/server:database/openSUSE_Factory_ARM/server:database.repo
zypper refresh
zypper install rrdtool-cached
For 15.6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/server:database/15.6/server:database.repo
zypper refresh
zypper install rrdtool-cached
For 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/server:database/15.5/server:database.repo
zypper refresh
zypper install rrdtool-cached