PDA

View Full Version : Zero out target drive?


DavidCB
12-19-2005, 12:34 PM
When preparing an external drive for cloning, does it make any difference if it is first erased with Disk Utility or does SuperDuper's erase have the same effect? Also, if Disk Utility should be used, does it make any difference if the drive has zeroes written to it or can it simply be erased?

Thank you,

David

dnanian
12-19-2005, 12:42 PM
Internally, we use Disk Utility to erase the drive, so there's no real difference. However, once you've put a backup on a drive, we keep track of it using its low-level ID, which is assigned during erase. Erasing outside of SD will cause us to lose track of the drive, so you'll be prompted to select it again.

It's a good idea, with a new drive, to zero it out. That way, any low-level defects will get remapped.

DavidCB
12-19-2005, 12:50 PM
It's a good idea, with a new drive, to zero it out. That way, any low-level defects will get remapped.

What about in the case of a drive you have been using but are now repartitioning?

David

dnanian
12-19-2005, 12:51 PM
Since you're wiping it anyway, David, might as well take the opportunity to test/remap the surface. It's hard to do once data is laid down!

DavidCB
12-19-2005, 12:54 PM
Since you're wiping it anyway, David, might as well take the opportunity to test/remap the surface. It's hard to do once data is laid down!

So maybe it's a good idea to zero out the drive every so often, say every few months or so, as a sort of maintenance procedure?

David

dnanian
12-19-2005, 12:58 PM
Well, no. Inside the drive, it automatically detects weak sectors and re-maps them on the fly. I think it's riskier to constantly move data back and forth than it is to just keep a good set of backups so you can recover from the (inevitable) failure.

I'd also suggest a very nice bit of software called SMART Reporter, which is free and available from VersionTracker. It'll keep you informed as to the SMART status of the drive, which *might* (no guarantee) give you some advance warning of drive failure. Hopefully. :)

DavidCB
12-19-2005, 01:05 PM
Well, no. Inside the drive, it automatically detects weak sectors and re-maps them on the fly. I think it's riskier to constantly move data back and forth than it is to just keep a good set of backups so you can recover from the (inevitable) failure.

The reason I am asking is that in this case, I am pressed for time so if it doesn't make a significant difference I would rather just erase than zero out the drive.

David

dnanian
12-19-2005, 01:09 PM
It's up to you, of course, but I would take this opportunity to do it. If you don't want to, don't... it's certainly not mandatory.

DavidCB
12-19-2005, 01:12 PM
I'd also suggest a very nice bit of software called SMART Reporter, which is free and available from VersionTracker. It'll keep you informed as to the SMART status of the drive, which *might* (no guarantee) give you some advance warning of drive failure. Hopefully. :)

Unfortunately I am using a FireWire drive, which this does not work with, but thank you anyway for the suggestion.

David

dnanian
12-19-2005, 01:16 PM
Indeed, true -- but it's helpful for the boot drive! :)

DavidCB
12-19-2005, 01:18 PM
It's up to you, of course, but I would take this opportunity to do it. If you don't want to, don't... it's certainly not mandatory.

I will probably err on the side of caution--always my practice with backups--and zero out the drive.

Thank you,

David