mount: special device /dev/sda1 does not exists

Question

I bought a Raspberry Pi and installed Raspbian and transmission. I want to connect my USB hard drive to save there the transmission's downloads. The HDD is formatted in FAT32, Windows recognizes it correctly. When I try to mount it in /dev/sda1 it prompts me:

mount: special device /dev/sda1 does not exists

fdisk finds only /dev/mmcblk0p1 and /dev/mmcblk0p2.

I also tried adding

/dev/sda1      /mnt/usb     vfat      uid=pi,gid=pi     0     0

to my /etc/fstab.

Can someone help me?

I tried mounting an NTFS-formatted USB flash drive and it mounts correctly.

Answer 1

Is the disk powering up? A USB HDD may require lots of current. I suggest you use a powered USB hub for the disk.

Answer 2

Occasionally I get windows USB storage devices that do not have a "1st" partition and have to be mounted without the partition specifier so in fstab I have

/dev/sdc        /mnt/sdc    auto        user,noatime        0 1
/dev/sdc1       /mnt/sdc1   auto        user,noatime        0 1

and mount them with either

mount /mnt/sdc1

or

mount /mnt/sdc

if /dev/sdc1 does not exist.

Answer 3

Run sudo blkid and if you can't see your HDD that's mean it still not powered up. The Pi's USB ports only have output ~500mA as default so it might not enough for your HDD.

In this case you have to increase current output of those USB ports. Add max_usb_current=1 to /boot/config.txt then reboot the Pi :)