NOTE don’t follow along without reading full post as some failed attempts are also documented.

First make a bootable Debian usb:

• download an ISO from Debian.
• format the USB if not already formatted I used ExFat to be crossplatform friendly. With a GUID partition scheme.
• df -h to identify device idenifier in /dev
• • /dev/disk4s2 15Gi 2.9Mi 15Gi 1% 94 481794 0% /Volumes/Debian
• unmount the disc diskutil unmount {identifier} eg /dev/disk4s2
• system_profiler SPUSBDataType is also interesting
• • however this was not working for me
• • The output of the above command I will post below this list with commentary
• dd if=debian-live-13.4.0-amd64-xfce.iso of=/dev/disk4s2 bs=4M; sync where if is the input file, of is the output file pointer, bs is the block size and sync is a directive to “Pad every input block to the input buffer size. Spaces are used for pad bytes if a block oriented conversion value is specified, otherwise NUL bytes are used.”
• • time for a meal break (at least at 4M block sizes).

``` Cruzer U:

      Product ID: 0x55a5
      Vendor ID: 0x0781  (SanDisk Corporation)
      Version: 1.00
      Serial Number: 4C530005940904114024
      Speed: Up to 480 Mb/s
      Manufacturer: SanDisk
      Location ID: 0x14200000 / 16
      Current Available (mA): 500
      Current Required (mA): 224
      Extra Operating Current (mA): 0
      Media:
        Cruzer U:
          Capacity: 16.01 GB (16,005,464,064 bytes)
          Removable Media: Yes
          BSD Name: disk4
          Logical Unit: 0
          Partition Map Type: GPT (GUID Partition Table)
          S.M.A.R.T. status: Verified
          USB Interface: 0
          Volumes:
            EFI:
              Capacity: 209.7 MB (209,715,200 bytes)
              File System: MS-DOS FAT32
              BSD Name: disk4s1
              Content: EFI
              Volume UUID: 0E239BC6-F960-3107-89CF-1C97F78BB46B
            disk4s2:
              Capacity: 15.79 GB (15,793,651,712 bytes)
              File System: MS-DOS
              BSD Name: disk4s2
              Content: Microsoft Basic Data
              ``` The section labeled `disk4s2` at the bottom seems to correspond to the file pointer at `/dev/`

more later…

So the ExFat disk format was not legible to the late 2013 Powerbook so second attempt used Mac Extended (journaled) which apparently can be read also by Linux.

Sure is slow. Bigger block size next time perhaps:

The recommended block size for the dd command typically ranges from 64K to 16M, depending on your specific hardware and use case. It’s best to start with a block size that is a multiple of your disk’s physical block size for optimal performance.

There is some further discussion here. UPDATE tried 32m block size as well and still a slow process.