WARNING: This blog post was posted at approximately 3 AM. As a result, it is not very well defined. Had I been thinking, I would have been more to the point. As it is, I may repost more info about the Seagate HD when it is successfully RMAd.
One of my hard drives is making sounds that indicate that it could fail at any time; In order to prevent any losses, I ordered a new drive. I spent a while copying all of my data from one drive to the next (I generally have 2 drives in my computer at a given time; the drive closer to failure contains data that is broadly available online, so losses should be minimal if anything happens, while my personal data is semiannually burned to disc and regularly synced to my brother’s computer). At any rate, I finished the migration, and started updating my install on the new drive.
The next morning I got up and found that my computer was making a horribly disturbing sound. The update process had blocked on a prompt for my acceptance of a license agreement. Gkrellm told me that data was not being transfered, so the sound was simply the spinning of the platters. I ran “hdparm -y /dev/olddrive” and “hdparm -C /dev/olddrive” to stop my old drive to make sure it wasn’t responsible for the sound, and then recorded the sound for documentation purposes.
I have a pretty good recording setup, so the recording is probably about as good quality as is practical – or even better. I heard it as soon as I entered the room, so it was fairly loud – but my system is also fairly quiet. The sound at the very end is the sound of me clicking a (fairly loud) mouse from a foot away from the mic – which is about the same distance as the mic was from the disk.
At any rate, I’m in the habit of keeping multiple copies of my data around until I trust my drives and I need more space, so I was able to undo a few changes I had made to my older drive to make it usable as the master – so I should have a marginally useful system until the real replacement is mailed to me.
Wiping the Disk for RMA
As I had put nearly all of my data on the new drive, I want to wipe it before returning it – but I also want to return the drive asap. I had always used DBAN to wipe drives, but I figured I should be able to do it from my normal install.
I first found shred, which seemed like it should be quite effective (and useful for shredding specific files, depending on the file system). It puts random data over the drive in several passes, and it optionally zeros the drive on the final pass. Unfortunately, I noticed that it was taking a long time – it uses data from /dev/urandom, which means that the random number generator was cranking like mad. To sum it up, the bottleneck was the CPU, not the hard disk.
I next tried dding data from /dev/urandom over the file (this was before I completely understood how shred works). Not surprisingly, it was CPU bound as well (I’m guessing that disk throughput was at about 10% of its capacity).
Finally, I found wipe, which uses special patterns, much like DBAN, as opposed to pseudorandom data like shred. As a result, the data is probably slightly less securely wiped (although it should also be more consistent in its results), but the bottleneck is now the disk. I expect that it will take 3-4 hours per pass, as opposed to 30-40 hours per pass.
New Seagate Barracudas (.12)
This reminds me, the new barracudas seem to be getting great throughput, at least – though I can’t speak for their reliability. However, I should mention that the packing job was not as good as it could have been, so my issues should probably not be blamed on Seagate, at least not in their entirety. I bought the OEM drive from Newegg, but the bubble wrap they used has perforations so it can be torn easily. Unfortunately, one of the perforated lines lined up perfectly with the edge of the disk – not a good thing, as the perforations pop the bubbles along the line.
I actually took the bubble wrap and tested it to see how much room for error they had in packing. As it turns out, they have about 1.25 inches of give on either side before one of the corners will not be protected by the bubble wrap. It’s enough allowance so that it’s not generally a problem, but just the same, it may easily have been a factor in my experience.