Note: Any version of Windows compatible with Balena Etcher should make an appropriate substitution for Windows 10. sudo dd if='$HOME/Downloads/snow leopard install.iso' of=/dev/sdb bs=1M If necessary, make the appropriate substitutions. Here, an assumption is made that the ISO file name is snow leopard install.iso and the file resides in your Downloads folder. mount | grep /dev/sdbĮnter the command given below to create the USB flash drive installer. If necessary, make the appropriate substitutions in the rest of the steps. Here, an assumption is made that the name for the flash drive is sdb. If there are mounted volumes, then use the sudo unmount command to unmount them before proceeding. lsblkĮnter the command given below to determine if any volumes on the flash drive are mounted. Use the command given below to determine the name for the flash drive. Sudo dd if='$HOME/Downloads/snow leopard install.iso' of=/dev/r$DISK bs=1m Also, an assumption is made that the identifier is disk2. diskutil listĮnter the commands given below to create the USB flash drive installer. Use the command given below to determine the identifier for the flash drive. In other words, there is more than one way to create a USB flash drive installer from a Snow Leopard ISO file. This differs from the flash drive created using the Disk Utility, which used the Master Boot Record scheme. Note: This flashdrive will be using the Apple Partition Map scheme. Finally, click on the Restore button in the popup window. In the popup window, select restore from Mac OS X Install DVD, as shown below. Highlight the name Untitled, then click on the Restore button on the top of the Disk Utility application window. Use the Disk Utility application to erase the flash drive, as shown below. Use the Finder application to mount the Snow Leopard ISO file. The Snow Leopard ISO file was the same as discussed in this answer, which should be the same ISO you have linked to in your question. The flash drive needs to be at least 8 GB in size. This was tested using an iMac (21.5-inch, Mid 2011) 2.5 GHz Intel Core i5 with MacOS High Sierra 10.13.6 installed. So the OP should probably try the second method involving the use of the dd command or the third method involving Balena Etcher.

User John Mark Harrell's answer confirms this is also true when using Big Sur on an unspecified Mac.

The first method, which involves the Disk Utility application, failed to work when tested using macOS Catalina 10.15.7 on an iMac (21.5-inch, Late 2013) 2.9 GHz Quad-Core Intel Core i5. Creating a USB Flash Drive Installer from a Snow Leopard ISO Fileīelow are three methods.

Os x leopard bootable usb