Commit 4502bda7 authored by Constantinos Venetsanopoulos's avatar Constantinos Venetsanopoulos
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docs: image format details -> advanced section

parent 9cd69cad
Advanced Topics Advanced Topics
=============== ===============
.. _image-format-advanced:
Image Format
^^^^^^^^^^^^
snf-image supports 3 types of image formats:
* **extdump**: a raw dump of an ext{2,3,4} file system
* **ntfsdump**: a raw dump of an NTFS file system
* **diskdump** (recommended): a raw dump of a disk
extdump and ntfsdump image formats
++++++++++++++++++++++++++++++++++
Those two formats are dumps (raw copies using dd) of partitions hosting Linux
systems on ext{2,3,4} and Windows systems on ntfs file systems respectively.
Partitions hosting a Windows or Linux system that are suitable for dumping
should have the following properties:
* Be the first partition in the file system
* The OS they host should not depend on any other partitions
* Start at sector 2048
* Have a boot loader installed in the boot sector of the partition (not MBR)
* Have the root device in */etc/fstab* specified in a persistent way, using
UUID or LABEL (for extdump only)
Known Issues
------------
* For Linux systems, having grub installed in the partition is fragile and
things can go wrong when resizing the partitions, especially when shrinking.
* More complicated partition schemes are not supported.
diskdump image format (recommended)
+++++++++++++++++++++++++++++++++++
Diskdump is a newer format that overcomes most of the aforementioned issues.
This format is a dump (raw copy using dd) of a whole disk.
This design decision has the following benefits:
* Swap partitions are supported
* The system may use multiple partitions:
* dedicated partitions for /boot, /home etc in Linux
* system and boot partition in Windows
* There are no restrictions on starting sectors of partitions
Although diskdump is a lot more flexible than the older formats, there are
still some rules to follow:
* All devices in fstab should be specified by persistent names (UUID or LABEL)
* LVMs are not supported
* For Linux disks only ext{2,3,4} file systems are supported
* For FreeBSD disks only UFS file systems are supported
* For FreeBSD only GUID Partition Tables (GPT) are supported
Progress Monitoring Interface Progress Monitoring Interface
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
......
...@@ -24,56 +24,17 @@ following OS Parameters: ...@@ -24,56 +24,17 @@ following OS Parameters:
Image Format Image Format
^^^^^^^^^^^^ ^^^^^^^^^^^^
Right now 3 different types of image formats are supported: snf-image supports 3 different types of image formats:
* **diskdump** (recommended): a raw dump of a disk
* **extdump**: a raw dump of an ext{2,3,4} file system * **extdump**: a raw dump of an ext{2,3,4} file system
* **ntfsdump**: a raw dump of an NTFS file system * **ntfsdump**: a raw dump of an NTFS file system
* **diskdump**: a raw dump of a disk
extdump and ntfsdump image formats These are also the only valid values for the **img_format** OS parameter.
++++++++++++++++++++++++++++++++++ The **diskdump** type is the newest and recommended type. Thus, all sample
images we provide are of this type. For more details about the internals of
Those two formats are dumps (raw copies using dd) of partitions hosting Linux image formats please see the :ref:`corresponding advanced section
systems on ext{2,3,4} and Windows systems on ntfs file systems respectively. <image-format-advanced>`.
Partitions hosting a Windows or Linux system that are suitable for dumping
should have the following properties:
* Be the first partition in the file system
* The OS they host should not depend on any other partitions
* Start at sector 2048
* Have a boot loader installed in the boot sector of the partition (not MBR)
* Have the root device in */etc/fstab* specified in a persistent way, using
UUID or LABEL (for extdump only)
Known Issues
------------
* For Linux systems, having grub installed in the partition is fragile and
things can go wrong when resizing the partitions, especially when shrinking.
* More complicated partition schemes are not supported.
diskdump image format
+++++++++++++++++++++
Diskdump is a newer format that overcomes most of the aforementioned issues.
This format is a dump (raw copy using dd) of a whole disk.
This design decision has the following benefits:
* Swap partitions are supported
* The system may use multiple partitions:
* dedicated partitions for /boot, /home etc in Linux
* system and boot partition in Windows
* There are no restrictions on starting sectors of partitions
Although diskdump is a lot more flexible than the older formats, there are
still some rules to follow:
* All devices in fstab should be specified by persistent names (UUID or LABEL)
* LVMs are not supported
* For Linux disks only ext{2,3,4} file systems are supported
* For FreeBSD disks only UFS file systems are supported
* For FreeBSD only GUID Partition Tables (GPT) are supported
.. _image-id: .. _image-id:
......
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