MacOS 10.15 Catalina fails to burn bootable cdroms from ISOs

Not likely to impact most people, but occasionally I use an external USB dvd burner to make bootable disks for installing various OSes on older computers.

Previously before Catalina I would right click an ISO and select “Burn Image to…’ and this would work as it has for the past several MacOS releases. Now though when I click this option the menu disappears and nothing happens. A tip here suggested to double click this iso to mount it, and then right click the mounted disk and select “Burn Image’. While this does work to burn to a blank cdrom, the disk is not bootable, it appears to only copy the files to the cdrom and not burn it as a bootable disk, even if the iso is from a bootable disk.

Reading through the above post on the Apple site, this sounds like a bug in Catalina and has been logged.

Useful Sun OpenBoot Prom (OBP) commands

At power on: (useful reference)

Stop-A : stop the boot process, takes you to OBP ok prompt

Stop-N : reset to default NVRAM values

From go prompt (from article here):

  • to enable POST diags, not sent to monitor but sent via serial connection to a terminal or terminal emulator
setenv diag-switch? true

Turn off again with false

  • Turn off configured boot drive:
setenv auto-boot? false 

true to enable again

  • Manually boot from given device:
boot disk
boot cdrom

where disk and cdrom are device aliases that you can view with


Solaris 10 install on ESXi VM error: “ERROR: The disc you inserted is not a Solaris OS CD/DVD”

After going through all the setup options but before it gets to starting the actual install on an ESXi VM I get the error:

“ERROR: The disc you inserted is not a Solaris OS CD/DVD”

From this post here about the same error on a Dell server (I’m installing on a VM on an HP DL380 G7) with Solaris driver issues with ATAPI CD/DVD devices, I changed the virtual CD drive on my VM from SATA to IDE, and can now get past the error.