Greetings!
Got another basic question for the community 
After wiping a drive with dd , and calling mkfs.ext4 to set things up again, fstab seems to need to be refreshed somehow to allow a call to mount for the volume.
What might the "secret handshake" be to pull this off without first pulling the drive out???
Thanks --
Yes, you will have to edit /etc/fstab to add or change the entry for your new filesystem. Are you getting an error when you try:
mount -t ext4 /dev/something /mnt
You do need to explicitly remount the file system with a proper mount command. It won't magically remount itself.
You got me moving in the right direction.
In the end,
mount -t ext4 /dev/sdb1 /mnt/usb
turned the nut on my end 
Comically, I tried
mount -t ext4 /dev/sdb1 /dev
and watched all of the unmounted filesystems completely disappear (even GParted and TestDisk protested)! Rudely killed everything and rebooted to Parted Magic; only to see that all was still there, and happy as normal...
Any comments/insights on what might've happened?
Thanks again --
Hi,
Mounting a file system on a directory causes all below the directory to vanish until the file system is unmounted - not that easy when you have no device tree (/dev)
Regards
Dave
That is pretty funny 
/dev/ is folder where device files are kept -- the files UNIX/Linux need to access, among other things, disks. You opened your new partition overtop of that, blocking them all. (Kind of like setting a blank sheet of paper atop a written one; the stuff beneath still exists, but you don't see it.) Things already open won't be affected, but you won't be able to open anything else. This has wider effects than disks. You probably lost the ability to create new terminals too, as well as sound, mice, even the bit-bucket, anything which is a character or block device.
You might have been able to recover from that with umount /dev but a reboot is good too.
