# Updating an existing system from sources A common mechanism for upgrading a NetBSD system to a newer version is by rebuilding the system from sources and installing the results. This works both for stable releases such as [NetBSD 5.0](/releases/formal-5/) and for NetBSD-current. In particular, if you are running a stable NetBSD release in a production environment, you are encouraged to perform this procedure regularly in order to incorporate any security fixes that have been applied to the branch since its release. There are a variety of ways of achieving the goal of rebuilding NetBSD from source, and this chapter will guide you through the variety of options that are available. The chapter starts by showing first what the manual procedure looks like, and proceeds to describe some of automation tools that simplify the process. **Note**: Please remember to check [src/UPDATING](http://cvsweb.NetBSD.org/bsdweb.cgi/src/UPDATING) for the latest changes and special instructions that may be involved in upgrading the system.* ## Manual build and update procedure Most of the following steps can be done as ordinary user. Only the installation of a new kernel and the userland will require root privileges. Although `/usr` is choosen as the working directory in the following examples, the procedure can also take place in a user's home directory. Ordinary users have normally not the permissions to make changes in `/usr`, but this can be changed by root. Having up-to-date sources is a prerequisite for the following steps. [[Fetching by CVS|guide/fetch#cvs] informs about the ways to retrieve or update the sources for a release, stable or current branch (using CVS). Please always refer to the output of **build.sh -h** and the files `UPDATING` and `BUILDING` for details - it's worth it, there are *many* options that can be set on the command line or in `/etc/mk.conf` ### Building a new userland The first step is to build the userland: $ cd /usr/src $ ./build.sh -O ../obj -T ../tools -U distribution ### Building a new kernel The next step will build the kernel: $ cd /usr/src $ ./build.sh -O ../obj -T ../tools kernel= ### Installing the kernel and userland Installing the new kernel, rebooting (to ensure that the new kernel works) and installing the new userland are the final steps of the updating procedure: $ cd /usr/src $ su # mv /netbsd /netbsd.old # mv /usr/obj/sys/arch//compile//netbsd / # shutdown -r now ... $ cd /usr/src $ su # ./build.sh -O ../obj -T ../tools -U install=/ If the new kernel `netbsd` does not boot successfully, you can fall back on booting the `netbsd.old` kernel. ### Updating the system configuration files Run the `etcupdate` script ([etcupdate(8)](http://netbsd.gw.com/cgi-bin/man-cgi?etcupdate+8+NetBSD-5.0.1+i386)) and follow the instructions in the output for fixing obsolete files: # /usr/sbin/etcupdate -s /usr/src Optionally reboot to ensure all running services are using the new binaries: # shutdown -r now ### Summary 1. From the root of the source tree: $ cd /usr/src 2. Build the userland: $ ./build.sh -O ../obj -T ../tools -U -u distribution 3. Build the kernel: $ ./build.sh -O ../obj -T ../tools -U -u kernel=GENERIC 4. Install the kernel: $ cd ../obj/sys/arch//compile/GENERIC $ su # mv /netbsd /netbsd.old # cp netbsd /netbsd 5. Reboot into the new kernel: # shutdown -r now 6. Install the new userland: $ cd /usr/src $ su # ./build.sh -O ../obj -T ../tools -U install=/ 7. Update the system and configuration files;: # /usr/sbin/etcupdate -s /usr/src **Note**: In the procedure above, the `-u` option indicates an update process, and that a `make clean` operation should not be run before starting the build. This is useful when doing an update from a previous build and/or a fresh build. The `-U` option allows the entire build by a non-root user followed with an install by root. ## Using sysinst It is also possible to use `sysinst` to install a freshly built system. The steps are as follows: 1. Build a complete release: $ ./build.sh -O ../obj -T ../tools -U -u -x release 2. The resulting install sets will be in the `/usr/obj/releasedir/` directory. 3. Copy the install kernel to the root directory of your NetBSD system, reboot from it, and upgrade with `sysinst` (see [[Upgrading NetBSD|guide/upgrading]]). ## Using sysbuild and sysupgrade The sysbuild and sysupgrade tools (currently available in `pkgsrc/sysutils/sysbuild` and `pkgsrc/sysutils/sysupgrade` respectively) automate the full process of rebuilding NetBSD from sources (*including the retrieval of the sources from a CVS repository*) and installing the results with minimal effort. Both of these tools have configuration files to determine how to build a release and how to install it. Among other things, these specify the CVS repository to use, what architecture to build for, where to place the build files and what steps to perform during an upgrade. The files can be found in `/usr/pkg/etc/sysbuild/default.conf` and `/usr/pkg/etc/sysupgrade.conf`. The default configuration of both tools should let you get started with minimal effort. In their simplest form, you can do a full NetBSD build and upgrade your system to it by running these commands: # sysbuild build # sysupgrade auto ~/sysbuild/release/$(uname -m) And that's all that it takes. These invocations will do the following: 1. Download the source trees from CVS into `/usr/src` and `/usr/xsrc`. The latter is only fetched if your system has X11. And, if you already have the sources in your system, this will only update them to the newest version. 2. Build a new release into `~/sysbuild//`. This per-machine directory will include subdirectories like `obj`, `destdir`, etc. The build results will be left in `~/sysbuild/release//`. 3. Install a new kernel and unpack the new sets using the just-built release files. 4. Run both etcupdate and postinstall to aid you in merging new configuration changes into your system. For more details, please see the included `sysbuild(1)` and `sysupgrade(8)` manual pages, as well as the comments in the referenced configuration files. ### Tweak: Building as non-root The commands above depict the most basic and simple invocation of the tools using the *default configuration files*. One drawback is that you require root access during the build of the source tree so that sysbuild can upgrade the source trees under `/usr/src` and `/usr/xsrc`. It is recommended that you avoid building as root once you are familiar with the procedure, and this section show what is needed to do so with sysbuild. In order to build as non-root, you can either choose to store your source trees out of `/usr` (easiest) or give permissions to your user to modify the trees under `/usr` (good if you want to share the source tree with more than one user). If you want to store the source trees under your home directory, which is convenient for development purposes, simply edit `/usr/pkg/etc/sysbuild.conf` and add these settings: SRCDIR="${HOME}/sysbuild/src" [ ! -f /etc/mtree/set.xbase ] || XSRCDIR="${HOME}/sysbuild/xsrc" Once this is done, the `sysbuild build` invocation show above should just work under your unprivileged user. The upgrade procedure then becomes: $ sysbuild build ... become root ... # sysupgrade auto ~/sysbuild/release/$(uname -m) The other alternative, in case you want to maintain your source trees in the locations described by [hier(7)](http://netbsd.gw.com/cgi-bin/man-cgi?hier+7+NetBSD-5.0.1+i386), is to do the following as root: # mkdir -p /usr/src /usr/xsrc # chown -R :wsrc /usr/src /usr/xsrc ... and optionally add to wsrc in /etc/group ... After this, the default configuration file of sysbuild will let you place the files in these locations and let you do unprivileged builds. **Note**: If you have an an encrypted home partition, or another "special" filesystem you store your sources on, you should backup them somehwere you can easily access them! In case of a failed build you might want to rebuild without being able to access an encrypted partition. ### Tweak: Setting up nightly builds The `pkgsrc/sysutils/sysbuild-user` package can be used to configure and maintain an unprivileged system user to perform periodic (e.g. nightly) builds from source. This can come in very handy to closely track NetBSD-current. The installed user is appropriately named sysbuild, and is configured by default to run a full system build overnight. The results are left in `/home/sysbuild/release//`, which is the convenient default of sysupgrade's release directory. Any build failures will be reported to you by email. The behavior of sysbuild for this unprivileged user is configured in `/home/sysbuild/default.conf`. You can interact with sysbuild under this unprivileged user by running commands of the form: # su - sysbuild /usr/pkg/bin/sysbuild ... ## More details about the updating of configuration and startup files [etcupdate(8)](http://netbsd.gw.com/cgi-bin/man-cgi?etcupdate+8+NetBSD-current) is a script to help users compare, merge and install new configuration and startup files (files found in the `etc.tgz` distribution set) in `/dev`, `/etc` and `/root` after performing an operating system upgrade. The upgrade of the operating system could have been performed either by compiling sources or by extracting the distribution binaries. ### Using etcupdate with source files In case where the sources are in `/usr/src` the following command should be enough: # etcupdate But what if your NetBSD sources are in an alternative location, such as in `/home/jdoe/netbsd/src`? Don't worry, tell etcupdate the location of your source tree with `-s srcdir` and it will work just fine: # etcupdate -s /home/jdoe/netbsd/src ### Using etcupdate with binary distribution sets Sometimes it's not convenient to have the sources around but you still want to update the configuration and startup files. The solution is to feed `etc.tgz` (or `xetc.tgz`) to etcupdate via the `-s tgzfile` switch: # etcupdate -s /some/where/etc.tgz ### Using etcmanage instead of etcupdate The `etcmanage` perl script (available from [pkgsrc/sysutils/etcmanage](http://pkgsrc.se/sysutils/etcmanage) or as binary package) is an alternative to etcupdate(8). It should be used in the following way, in combination with [postinstall(8)](http://netbsd.gw.com/cgi-bin/man-cgi?postinstall+8+NetBSD-5.0.1+i386): # /usr/pkg/bin/etcmanage # /usr/sbin/postinstall