hdd

This is a simple guide, part of a series I'll call 'How-To Guide Without Ads'. In it, I'll show you how I completely initialize a hard drive so I can re-use it somewhere else (like Ceph) that doesn't like drives with partition information!

First, a warning: this blog post does not show how to zero a hard drive, or secure erase. That's a slightly different process.

But as someone with way too many storage devices (from testing, mostly), I find myself in the position of trying to use a spare drive in some place where it expects a brand new drive, but winds up failing because the drive had a partition, or had valid boot files from an SBC or something.

I wanted to document the easiest way in Linux to completely reset a hard drive—at least from Linux's perspective.

The impetus was when I was trying to get some hard drives added to a Ceph OSD, and the process that tried adding them ran into an error stating RuntimeError: Device /dev/sda has partitions.

A few months ago, I posted a video titled Enterprise SAS RAID on the Raspberry Pi... but I never actually showed a SAS drive in it. And soon after, I posted another video, The Fastest SATA RAID on a Raspberry Pi.

Well now I have actual enterprise SAS drives running on a hardware RAID controller on a Raspberry Pi, and it's faster than the 'fastest' SATA RAID array I set up in that other video.

A Broadcom engineer named Josh watched my earlier videos and realized the ancient LSI card I was testing would not likely work with the ARM processor in the Pi, so he was able to send two pieces of kit my way:

I am using a 2011 Mac mini as a backup server for all the data I store on iCloud, and for the first few days while I was setting up the Mac, I noticed the 4 TB and 2 TB external USB drives I had plugged in would spin down after a few minutes, and I would have blissful silence as long as there wasn't an active operation on that Mac (which should be fairly rare; just hourly Time Machine backups and periodic SSD activity since the iCloud libraries are all on SSD).

However, after a few weeks, I noticed that at least one of the two hard drives runs continuously, 24x7. Something on the Mac mini must keep hitting the drive and preventing it from spinning down.

To see what was happening, I used sudo fs_usage | grep VOLUME (in my case, VOLUME is 4\ TB\ Utility) to monitor what processes were accessing the drive, and what files they were accessing. After a few minutes watching (and doing nothing else on the computer, to make sure I wasn't causing any extra filesystem seeks), there were a couple regular culprits: