diskutil list
/dev/disk0 (internal, physical):
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *251.0 GB disk0
1: EFI EFI 314.6 MB disk0s1
2: Apple_APFS Container disk1 250.7 GB disk0s2
/dev/disk1 (synthesized):
#: TYPE NAME SIZE IDENTIFIER
0: APFS Container Scheme - +250.7 GB disk1
Physical Store disk0s2
1: APFS Volume Macintosh HD - Data 152.5 GB disk1s1
2: APFS Volume Preboot 1.8 GB disk1s2
3: APFS Volume Recovery 1.1 GB disk1s3
4: APFS Volume VM 2.1 GB disk1s4
5: APFS Volume Macintosh HD 8.9 GB disk1s5
6: APFS Snapshot com.apple.os.update-... 8.9 GB disk1s5s1
/dev/disk2 (external, physical):
#: TYPE NAME SIZE IDENTIFIER
0: FDisk_partition_scheme *15.5 GB disk2
1: Windows_FAT_32 15.5 GB disk2s1
➜ diskutil unmountDisk /dev/disk2
Unmount of all volumes on disk2 was successful
➜ sudo dd if=/Users/d-inoue/Downloads/rhrexboot-2020-08.iso of=/dev/disk2 bs=512k
Password:
2417+1 records in
2417+1 records out
1267597312 bytes transferred in 800.997718 secs (1582523 bytes/sec)
it took about 31min 8sec.