Rpi 3 Mount USB-HDD

Hello! Nice linux.
I install on Raspberry pi 3 like sys mode.
How i can mount USB-HDD?

blkid
/dev/sda1: LABEL="main" UUID="9a6d3082-b02f-4698-8175-7801e92da852" TYPE="ext4" this usb HDD
/dev/mmcblk0p2: UUID="7fd6ca63-c181-46e3-9d21-3330e7ceb82c" TYPE="ext4"
/dev/mmcblk0p1: UUID="8497-6186" TYPE="vfat"

I try modify fstab:

UUID=9a6d3082-b02f-4698-8175-7801e92da852 /mnt/main ext4 defaults 0 0

not help

or
/dev/sda1 /mnt/main ext4 defaults 0 0

still nothing. any ideas?