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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?

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    about 5% of total disk space is reserved on linux systems. That account for 100GB of missing space on your hard drive. Maybe it got consumed by damaged inodes. How old is your hard drive? – saga Oct 26 '16 at 17:08
  • I'm running "sudo dd if=/dev/zero of=/dev/sdb bs=4M status=progress". I have the sdb1 wipe (same command otherwise) running right now, it's up to 687GB. According to fdisk, the sdb device is 1.7GiB, while the sdb1 device is 1.8TiB. How does this happen? – Harold Schreckengost Oct 26 '16 at 17:58
  • Can you include the output of fdisk -l /dev/sdb in your question? – Mark Plotnick Oct 26 '16 at 18:10
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    Hmm. So fdisk doesn't show that there are any partitions. Is /dev/sdb1 a special device file, or an ordinary file? – Mark Plotnick Oct 26 '16 at 18:22
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    Can you add the output of ls -l /dev/sdb* to your question? – Mark Plotnick Oct 26 '16 at 23:30
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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.

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