# Re-Installation

A reinstall can be done without doing anything other than doing the PXE boot, but there are some caveats to consider:

## Netboot
After the initial installation the boot mode has been reset from netboot to local so it will then always boot from the local disk. For a redeployment the netboot needs to be set anew.

```bash
bob node netboot $FQDN
```

On UEFI based systems netboot also needs to be always selected by the UEFI menu!

## Puppet Certificates

The puppet client certificate is saved on the puppet server. By default corresponding certificate on the client is tried to be saved by the kickstart script. If you do a new install to a blank drive, but the puppet server has a certificate saved for the host, the client will generate a new cert, but the server will not, so the certificates saved on the 2 sides, will not match and will never work. In this case both sides need to be cleaned up before a new puppet run is attempted.

Puppet client certs can be deleted at https://puppet.psi.ch/ and on that page, the command to delete the client cert is specified.

To access https://puppet.psi.ch one needs to authenticate with your username/password. The server uses a invalid https certificate that is not accepted by modern safari/chrome any more. Use Firefox as a workaround.

## Different Hiera Environment

There are some safeguards build in to prevent machines being (temporarily) moved from one hiera environment to another (e.g. to get hold of the other environts encryption secrets). 

If a machine needs to be moved/reinstalled from one hiera environment into another it might be necessary to delete some files on the puppet server:

```bash
[root@puppet ~]# cd /srv/puppet/alias_reservation/
[root@puppet alias_reservation]# ll x04sa-cons-01*
lrwxrwxrwx. 1 puppet puppet 11  1. Mai 09:49 x04sa-cons-01 -> ../data/sls
lrwxrwxrwx. 1 puppet puppet 11  1. Mai 09:49 x04sa-cons-01.psi.ch -> ../data/sls
```

```{note}
If the host has a long hostname it might be necessary to also delete the link with the hashed name! e.g. `awi-cha-dba8004`
```