Az cli backups

az disk grant-access --duration-in-seconds 86400 --access-level Read --name azd0-foo_OsDisk_1 --resource-group MY-RESOURCE-GROUP

Download

az login --scope https://management.core.windows.net//.default
url="https://md-hdd-..myurlfrom-grant-access"
file_name=azd0-foo.vhd
az storage blob download -f ${file_name} --blob-url ${url}

Backup disks via array in MY-RGRP resource group

#!/bin/bash
set -eux
rg_name=MY-RGRP
ttl=43200
ttl=86400

disks=(
azd0-foo_osdisk01
azd0-foo_datadisk01
)

jq -h || sudo apt install -y jq

main(){
  for disk_name in "${disks[@]}"; do
    file_name="${disk_name}__${rg_name}.vhd"
    echo Exporting disk $file_name in 10 seconds; sleep 10
    r=$(az disk grant-access --duration-in-seconds $ttl --access-level Read --name $disk_name --resource-group $rg_name)    url=$(echo $r | jq -r '.accessSas')
    echo Downloading disk vhd for $file_name from $url in 10 seconds; sleep 10
    echo Downloading now
    az storage blob download -f ${file_name} --blob-url ${url}
    tar -czvf ${file_name}.tgz ${file_name}
    rm ${file_name}
  done
}

main