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--- ubuntu:iso:create_iso_from_a_bootable_usb_drive:using_dd [2024/07/30 14:22] – created peter
+++ ubuntu:iso:create_iso_from_a_bootable_usb_drive:using_dd [2024/07/30 14:24] (current) – [Make a Copy] peter
@@ Line 1: / Line 1: @@
 ====== Ubuntu - ISO - Create ISO from a Bootable USB Drive - Using dd ======
+**dd** is a powerful Linux tool for a wide range of disk-related tasks:
+ * creating disk images
+ * copying data between devices
+ * performing low-level operations on data
+dd makes a bit-for-bit copy of the USB drive’s contents into a single ISO file.
+----
+===== Make a Copy =====
+Create a copy from the bootable USB to a file:
+<code bash>
+sudo dd if=/dev/sdb1 of=myisofile bs=4M status=progress
+</code>
+<WRAP info>
+**NOTE:**  This creates a raw binary copy of the USB in the current directory.
+These are optional parameters, but do help:
+  * **bs=4M**:  Read and write up to 4M at a time; to make I/O faster.
+  * **status=progress**:  Provide a progress report while dd runs.
+</WRAP>
+----
+===== Convert the raw binary file to an ISO format =====
+Install genisoimage:
+<code bash>
+sudo apt install genisoimage
+</code>
+----
+===== Convert the raw file to an ISO format =====
+<code bash>
+sudo genisoimage -o converted.iso -input-charset utf-8 -R -J myisofile
+</code>
+<WRAP info>
+**NOTE:**
+  * **-o**: converted.iso specifies the name of the output ISO file in proper ISO 9660 format.
+  * **-input-charset utf-8**: sets the character encoding for the ISO image.
+  * **-R**: generates the Rock Ridge extension for UNIX file attributes.
+  * **-J**: generates the Joliet extension for Windows file systems.
+The output **converted.iso** will be in a standard ISO format and can be used for various purposes, including burning to optical media or distributing bootable images.
+</WRAP>
+----
+===== Verify the ISO Format =====
+Perform a simple check to examine the ISO’s structure and extract information about its content.
+<code bash>
+sudo isoinfo -d -i converted.iso
+</code>
+returns:
+<code>
+CD-ROM is in ISO 9660 format
+System id: LINUX
+Volume id: CDROM
+...
+Volume set size is: 1
+Volume set sequence number is: 1
+Logical block size is: 2048
+Volume size is: 123456
+Joliet with UCS level 3 found
+Rock Ridge signatures version 1 found
+</code>
+<WRAP info>
+**NOTE:**  **isoinfo** is a part of the genisoimage package:
+The resulting output confirms that the converted.iso file is in the ISO format.
+It provides details about its volume and file system attributes and support for extended file names and attributes.
+</WRAP>