Installroot Parameter

Description

The --installroot parameter is used to specify an alternative installroot, relative to where all packages will be installed. Think of it like doing chroot <root> dnf, except using --installroot allows DNF5 to work before the chroot is created.

cachedir, log files, releasever, and gpgkey are taken from or stored in the installroot. GPG keys are imported into the installroot from a path relative to the host which can be specified in the repository section of configuration files.

configuration file, reposdir, and vars are taken from inside the installroot, unless the command-line argument --use-host-config is passed, in which case the configuration and environment from the host system will be used.

Note: When a path is specified within a command line argument (--config=CONFIG_FILE_PATH in case of configuration file, --setopt=reposdir=/path/to/repodir for reposdir, --setopt=logdir=/path/to/logdir for logdir, or --setopt=varsdir=/paths/to/varsdir for vars), then this path is always relative to the host with no exceptions. pluginpath and pluginconfpath are relative to the host.

Note: You may also want to use the command-line option --releasever=RELEASEVER when creating the installroot, otherwise the $releasever value is taken from the rpmdb within the installroot (and thus it is empty at the time of creation and the transaction will fail). If --releasever=/ is used, the releasever will be detected from the host (/) system. The new installroot path at the time of creation does not contain the repository, releasever and dnf.conf files.

On a modular system you may also want to use the --setopt=module_platform_id=<module_platform_name:stream> command-line option when creating the installroot, otherwise the module_platform_id value will be taken from the /etc/os-release file within the installroot (and thus it will be empty at the time of creation, the modular dependency could be unsatisfied and modules content could be excluded).

Examples

dnf5 --installroot=INSTALLROOT --releasever=RELEASEVER install system-release: Permanently sets the releasever of the system in the INSTALLROOT directory to RELEASEVER.
dnf5 --installroot=INSTALLROOT --setopt=reposdir=PATH --config /path/dnf.conf upgrade: Upgrades packages inside the installroot from a repository described by --setopt using configuration from /path/dnf.conf.