3 state boot » History » Version 2
Šimon Lukašík, 04/04/2014 09:36 AM
small typo
| 1 | 1 | Greg Sutcliffe | h1. 3 State Boot Support |
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| 2 | |||
| 3 | {{toc}} |
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| 4 | |||
| 5 | Foreman 1.1 now supports a 3 state boot model. This document describes the behaviour of the system, and how to make use of it. |
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| 6 | |||
| 7 | h2. The old way |
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| 8 | |||
| 9 | Until now Foreman has only ever cared about 2 states. A machine is either: |
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| 10 | |||
| 11 | * Known to Foreman _and_ in Build mode |
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| 12 | 2 | Šimon Lukašík | - A MAC-specific PXE file is written to launch the installer |
| 13 | 1 | Greg Sutcliffe | * Known to Foreman _and not_ in Build mode, _or_ unknown to Foreman |
| 14 | - The global default PXE file instructs the machine to localboot |
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| 15 | |||
| 16 | This makes it impossible to handle unknown machines separately from known, built machines. |
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| 17 | |||
| 18 | h2. The new way |
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| 19 | |||
| 20 | We now separate the last two states: |
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| 21 | |||
| 22 | * Known to Foreman _and_ in Build mode |
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| 23 | - A MAC-specific PXE file is written to laucnh the installer |
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| 24 | * Known to Foreman _and not_ in Build mode |
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| 25 | - A MAC-specific PXE file is written to instruct localboot |
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| 26 | * Unknown to Foreman |
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| 27 | - The global default PXE file instructs the machine to _whatever_ |
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| 28 | |||
| 29 | h2. How it works |
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| 30 | |||
| 31 | Until now, we've relied on a single, global default template (PXE Default File) which is written to all the proxies via the button on the Provisioning Template page. |
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| 32 | |||
| 33 | We now add a new global template (PXE Localboot Default). This does not need to be deployed to all the proxies, as it will be written when a host exits Build mode. So our state+file list becomes: |
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| 34 | |||
| 35 | * Known to Foreman _and_ in Build mode |
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| 36 | - A MAC-specific PXE file is written (OS-specific installer template) |
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| 37 | * Known to Foreman _and not_ in Build mode |
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| 38 | - A MAC-specific PXE file is written (Global PXE Localboot template) |
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| 39 | * Unknown to Foreman |
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| 40 | - The global default PXE file is used (PXE Default File template) |
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| 41 | |||
| 42 | h2. Defaults to 'off' |
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| 43 | |||
| 44 | Actually, this feature is always on. However, by default, the two global templates contain the same PXE instructions (i.e. boot from local disk). Thus, the current behaviour of Foreman is preserved - if a machine is unknown _or_ not in build mode, it will get a template that instructs it to boot from local disk. |
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| 45 | |||
| 46 | h2. How to use it |
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| 47 | |||
| 48 | Suppose you want all unknown hardware to boot into a custom ramdisk image that you have added to the TFTP server. To do this simply, edit the PXE Default File template to represent your desired behaviour. For example: |
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| 49 | |||
| 50 | DEFAULT menu |
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| 51 | PROMPT 0 |
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| 52 | MENU TITLE PXE Menu |
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| 53 | TIMEOUT 200 |
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| 54 | TOTALTIMEOUT 6000 |
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| 55 | ONTIMEOUT isoboot |
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| 56 | |||
| 57 | LABEL isoboot |
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| 58 | LINUX boot/memdisk |
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| 59 | INITRD boot/foreman.iso |
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| 60 | APPEND iso raw |
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| 61 | |||
| 62 | Then click Build PXE Default to redeploy the Global template. |
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| 63 | |||
| 64 | h2. Caveats |
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| 65 | |||
| 66 | Currently the system will deploy the global template to _all_ TFTP proxies. That may cause unintended behaviour if you want to boot-to-ramdisk only on a single network. |
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| 67 | |||
| 68 | One workaround would be to manually fix the default file for the appropriate subnet after deploying the template. |