The isostick can only read files from FAT32 partitions. Unfortunately, FAT32 has a maximum file size of 4GB. To overcome this, isostick can read ISO files which are split into multiple parts, up to a maximum of 10 parts (so, 40GB is the maximum supported image size).
Requirements for ISO file parts:
- Each part must only contain the ISO file data -- do not add any headers.
- Each part's size must be evenly divisible by 2048bytes (the size of a CD/DVD sector).
- Each part must use sequential extensions from .iso.0 thru a maximum of .iso.9
For example if you are splitting a 6GB ISO named Win7x64.iso, you may end up with Win7x64.iso.0 (4GB) and Win7x64.iso.1 (2GB). Of course, you could also split it into two 3GB files, or any other combination, so long as the above limits are obeyed.
If you're on Windows you will need to get split from the GNU CoreUtils package. Linux and MacOS X should come with split.
split -a 1 -b 4000m -d blah.iso blah.iso.Change "blah" to the name of the iso file, and be sure to keep that '.' at the end of the command!
Explanation of command-line options:
- -a 1 Suffixes are only one character long
- -b 4000m Maximum size of each file is 4000MB
- -d Use numeric suffixes
For those uncomfortable with a command prompt: I haven't found a good free split utility that doesn't have its drawbacks, but here's a couple:
- HJSplit does the job, but it is (at least in my testing) painfully slow.
Also it will produce .iso.001, .iso.002, and so, which you will have to rename to .iso.0, .iso.1, etc.
Just choose 'Split', and enter a split size of 4000 Mbytes.
- HxD has an option under Extras -> File Tools -> Split, here's an example setup:
HxD-Split.png 23.1KB 15 downloads
By choosing "Prompt for name" it will ask you for each filename, and you can specify the .iso.0, .iso.1, etc file extension for each. Set the size to 4000MB as shown.