Cloning to a larger hard drive

Kj,

OK, I'll bite.... Why?

If a drive is targeted in Disk Utility for "zeroing," bad blocks will be mapped out. I'm fairly certain that this isn't the case when volumes are selected (I don't think it could be), but zeroing a drive does scan for errors and maps out anything that is found. I can't think of any additional benefit from using manufacturer's software.

Scott

I agree.

If you remember the old days of SCSI all formatters did low-level formatting. With the advent of ATA drives there was no more low-level formatting. That was all done at the factory, but I guess the idea of doing a low-level format has persisted even though SCSI drives are not that widely used in consumer machines.

When I first started using machines with ATA drives the first thing I was looking for was the low-level formatter. Seemed like you couldn't do a low-level format on an ATA drive. Warnings abounded about how the drive would be permanently damaged if the used performed a low-level format. Took me a little learning to get over my desire to low-level format a drive. I got over it.

From PCguide.com:

Warning: Only use a low-level zero-fill or diagnostic utility designed for your particular hard disk. You can download one for free from your drive manufacturer's web site. Even though damage probably won't result from using the wrong program, you may lose data and you may also complicate any warranty service you try to have performed on the drive. (Technical support people at "Company X" generally don't like to hear that you used a utility on their drive written by "Company Y".)

http://www.pcguide.com/ref/hdd/geom/formatUtilities-c.html

Kj

Kj,

Hmmm. Windows 9.x, booting to DOS, floppy disks?? That article is from 2001, which is a very, very long time ago in tech terms. Particularly in drive tech terms.

Scott

Maybe so, but I recently called seagate tech support on a 500GB drive I knew was bad, but still in
warranty and they insisted that I run their software on the drive before giving me a RMA to return
it for repair.

If it is not in warranty I will use whatever software I want on it.

Kj

True low-level formatting involves writing the guide or "servo" data to the media that make it possible for the head assembly to find each data track. Until circa 1999 or 2000, pretty much every drive (SCSI or ATA) found in personal computers could rewrite this servo formatting data to the disk surface with the drive's own head assembly, just like it writes to data sector areas. Because of this, true low-level formatting could be done in the field with a suitable utility.

But as ways were found to increase areal data densities to ever higher levels (more tracks per inch & more sectors per track) it became necessary to embed servo data very precisely throughout the tracks between data sectors, so much so that it has become impossible to write it with the drive's own head assembly with the required precision. Modern high density drives are low-level formatted at the factory using special high-precision "servowriter" machines in clean room environments before the drives are sealed with cover plates. This low-level formatting data must last for the life of the drive -- if it becomes damaged, the drive will become unusable.

Seagate says that its current tool is still referred to as a low level formatter but that this is "somewhat of a misnomer" since it doesn't really do the same thing as a factory low-level format. Instead, it is a tool that initializes the drive by writing to its data sectors. In older drives that could self-write servo data, re-initializing data sectors provided the benefit of erasing any trace of servo data that might be left in the data sector area, which could confuse the servo positioning mechanism. In modern drives this is a non-issue: servowriters don't write to data areas, the servo signals they embed are distinctly different from data sector signals, & the drive's logic prevents it from writing to servo areas. If it doesn't, there is nothing users can do about it except replace the drive.