If you want to set more than one persistence dat files for one ISO file.
Code:
{
"persistence":[
{
"image":"/iso/ubuntu-21.04-desktop-amd64.iso",
"backend":[
"/persistence/persistence_ext4_512MB_casper-rw.dat",
"/persistence/persistence_ext4_512MB_writable.dat"
]
}
]
}