What might cause a block device to somehow be smaller than its partitions?

Question

I'm trying to wipe an IOSafe external drive, and I'm running into a major problem. When I run dd to wipe the full disk (/dev/sdb) it errors out at the 1.8 GB mark (it's a 2 TB disk), saying no space left on device.

sudo dd if=/dev/zero of=/dev/sdb bs=4M status=progress

When I go to wipe /dev/sdb1 (the partition, that oddly enough shouldn't even exist, because I wiped the partition table), it will wipe that.ea

Any idea what's going on and what to do about it?

Output of fdisk -l /dev/sdb:

Disk /dev/sdb: 1.7 GiB, 1770082304 bytes, 3457192 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x1f7d3f72

As requested, the output of ls -l /dev/sdb*

$ ls -l /dev/sdb*
-rw-r--r-- 1 root root 1770082304 Oct 27 07:17 /dev/sdb
brw-rw---- 1 root disk      8, 17 Oct 27 07:18 /dev/sdb1

Now that I see that output, does the 'b' in the sdb1 line denote a block device?

Answer 1

Edit: Thanks to the answer to Mark Plotnick's question, it is demonstrated

/dev/sdb has been removed as a device node, so you've then filled /dev (which is a tmpfs and hence limited by RAM). As you surmise, the b next to sdb1 is what shows that it's a block device.

/dev should be recreated if you reboot.