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authorhulkoba <jacoba@neighbourhood.ie>2024-02-26 13:57:40 +0100
committerhulkoba <jacoba@neighbourhood.ie>2024-03-27 07:11:56 +0100
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index 5416a22276..d2841a5a7e 100644
--- a/docs/CONVERTING_TO_HOMED.md
+++ b/docs/CONVERTING_TO_HOMED.md
@@ -8,11 +8,12 @@ SPDX-License-Identifier: LGPL-2.1-or-later
# Converting Existing Users to systemd-homed managed Users
Traditionally on most Linux distributions, regular (human) users are managed
-via entries in `/etc/passwd`, `/etc/shadow`, `/etc/group` and
-`/etc/gshadow`. With the advent of
+via entries in `/etc/passwd`, `/etc/shadow`, `/etc/group` and `/etc/gshadow`.
+With the advent of
[`systemd-homed`](https://www.freedesktop.org/software/systemd/man/systemd-homed.service.html)
it might be desirable to convert an existing, traditional user account to a
-`systemd-homed` managed one. Below is a brief guide how to do that.
+`systemd-homed` managed one.
+Below is a brief guide how to do that.
Before continuing, please read up on these basic concepts:
@@ -23,20 +24,20 @@ Before continuing, please read up on these basic concepts:
## Caveat
-This is a manual process, and possibly a bit fragile. Hence, do this at your
-own risk, read up beforehand, and make a backup first. You know what's at
-stake: your own home directory, i.e. all your personal data.
+This is a manual process, and possibly a bit fragile.
+Hence, do this at your own risk, read up beforehand, and make a backup first.
+You know what's at stake: your own home directory, i.e. all your personal data.
## Step-By-Step
Here's the step-by-step guide:
0. Preparations: make sure you run a distribution that has `systemd-homed`
- enabled and properly set up, including the necessary PAM and NSS
- configuration updates. Make sure you have enough disk space in `/home/` for
- a (temporary) second copy of your home directory. Make sure to backup your
- home directory. Make sure to log out of your user account fully. Then log in
- as root on the console.
+ enabled and properly set up, including the necessary PAM and NSS configuration updates.
+ Make sure you have enough disk space in `/home/` for a (temporary) second copy of your home directory.
+ Make sure to backup your home directory.
+ Make sure to log out of your user account fully.
+ Then log in as root on the console.
1. Rename your existing home directory to something safe. Let's say your user
ID is `foobar`. Then do:
@@ -45,92 +46,86 @@ Here's the step-by-step guide:
mv /home/foobar /home/foobar.saved
```
-2. Have a look at your existing user record, as stored in `/etc/passwd` and
- related files. We want to use the same data for the new record, hence it's good
- looking at the old data. Use commands such as:
+2. Have a look at your existing user record, as stored in `/etc/passwd` and related files.
+ We want to use the same data for the new record, hence it's good looking at the old data.
+
+ Use commands such as:
```
getent passwd foobar
getent shadow foobar
```
- This will tell you the `/etc/passwd` and `/etc/shadow` entries for your
- user. For details about the fields, see the respective man pages
+ This will tell you the `/etc/passwd` and `/etc/shadow` entries for your user.
+ For details about the fields, see the respective man pages
[passwd(5)](https://man7.org/linux/man-pages/man5/passwd.5.html) and
[shadow(5)](https://man7.org/linux/man-pages/man5/shadow.5.html).
- The fourth field in the `getent passwd foobar` output tells you the GID of
- your user's main group. Depending on your distribution it's a group private
- to the user, or a group shared by most local, regular users. Let's say the
- GID reported is 1000, let's then query its details:
+ The fourth field in the `getent passwd foobar` output tells you the GID of your user's main group.
+ Depending on your distribution it's a group private to the user, or a group shared by most local, regular users.
+ Let's say the GID reported is 1000, let's then query its details:
```
getent group 1000
```
- This will tell you the name of that group. If the name is the same as your
- user name your distribution apparently provided you with a private group for
- your user. If it doesn't match (and is something like `users`) it apparently
- didn't. Note that `systemd-homed` will always manage a private group for
- each user under the same name, hence if your distribution is one of the
- latter kind, then there's a (minor) mismatch in structure when converting.
+ This will tell you the name of that group.
+ If the name is the same as your user name your distribution apparently provided you with a private group for your user.
+ If it doesn't match (and is something like `users`) it apparently didn't.
+ Note that `systemd-homed` will always manage a private group for each user under the same name,
+ hence if your distribution is one of the latter kind, then there's a (minor) mismatch in structure when converting.
- Save the information reported by these three commands somewhere, for later
- reference.
+ Save the information reported by these three commands somewhere, for later reference.
3. Now edit your `/etc/passwd` file and remove your existing record
- (i.e. delete a single line, the one of your user's account, leaving all
- other lines unmodified). Similar for `/etc/shadow`, `/etc/group` (in case
- you have a private group for your user) and `/etc/gshadow`. Most
- distributions provide you with a tool for that, that adds safe
+ (i.e. delete a single line, the one of your user's account, leaving all other lines unmodified).
+ Similar for `/etc/shadow`, `/etc/group` (in case you have a private group for your user) and `/etc/gshadow`.
+ Most distributions provide you with a tool for that, that adds safe
synchronization for these changes: `vipw`, `vipw -s`, `vigr` and `vigr -s`.
4. At this point the old user account vanished, while the home directory still
- exists safely under the `/home/foobar.saved` name. Let's now create a new
- account with `systemd-homed`, using the same username and UID as before:
+ exists safely under the `/home/foobar.saved` name.
+ Let's now create a new account with `systemd-homed`, using the same username and UID as before:
- ```
- homectl create foobar --uid=$UID --real-name=$GECOS
- ```
+ ```sh
+ homectl create foobar --uid=$UID --real-name=$GECOS
+ ```
In this command line, replace `$UID` by the UID you previously used,
- i.e. the third field of the `getent passwd foobar` output above. Similar,
- replace `$GECOS` by the GECOS field of your old account, i.e the fifth field
- of the old output. If your distribution traditionally does not assign a
- private group to regular user groups, then consider adding `--member-of=`
- with the group name to get a modicum of compatibility with the status quo
- ante: this way your new user account will still not have the old primary
+ i.e. the third field of the `getent passwd foobar` output above.
+ Similar, replace `$GECOS` by the GECOS field of your old account, i.e the fifth field of the old output.
+ If your distribution traditionally does not assign a private group to regular user groups,
+ then consider adding `--member-of=` with the group name to get a modicum of compatibility with the status quo ante:
+ this way your new user account will still not have the old primary
group as new primary group, but will have it as auxiliary group.
Consider reading through the
[homectl(1)](https://www.freedesktop.org/software/systemd/man/homectl.html)
- manual page at this point, maybe there are a couple of other settings you
- want to set for your new account. In particular, look at `--storage=` and
- `--disk-size=`, in order to change how your home directory shall be stored
+ manual page at this point, maybe there are a couple of other settings you want to set for your new account.
+ In particular, look at `--storage=` and `--disk-size=`, in order to change how your home directory shall be stored
(the default `luks` storage is recommended).
-5. Your new user account exists now, but it has an empty home directory. Let's
- now migrate your old home directory into it. For that let's mount the new
- home directory temporarily and copy the data in.
+1. Your new user account exists now, but it has an empty home directory.
+ Let's now migrate your old home directory into it.
+ For that let's mount the new home directory temporarily and copy the data in.
```
homectl with foobar -- rsync -aHANUXv --remove-source-files /home/foobar.saved/ .
```
This mounts the home directory of the user, and then runs the specified
- `rsync` command which copies the contents of the old home directory into the
- new. The new home directory is the working directory of the invoked `rsync`
- process. We are invoking this command as root, hence the `rsync` runs as
- root too. When the `rsync` command completes the home directory is
- automatically unmounted again. Since we used `--remove-source-files` all files
- copied are removed from the old home directory as the copy progresses. After
- the command completes the old home directory should be empty. Let's remove
- it hence:
+ `rsync` command which copies the contents of the old home directory into the new.
+ The new home directory is the working directory of the invoked `rsync` process.
+ We are invoking this command as root, hence the `rsync` runs as root too.
+ When the `rsync` command completes the home directory is automatically unmounted again.
+ Since we used `--remove-source-files` all files copied are removed from the old home directory as the copy progresses.
+ After the command completes the old home directory should be empty.
+ Let's remove it hence:
```
rmdir /home/foobar.saved
```
-And that's it, we are done already. You can log out now and should be able to
-log in under your user account as usual, but now with `systemd-homed` managing
-your home directory.
+And that's it, we are done already.
+You can log out now and should be able to log in under your user account as usual,
+but now with `systemd-homed` managing your home directory.