What is meant by low level formatting?

Answer 1

Low-level formatting is the process of outlining the positions of the tracks and sectors on the hard disk, and writing the control structures that define where the tracks and sectors are. This is often called a "true" formatting operation, because it really creates the physical format that defines where the data is stored on the disk. The first time that a low-level format ("LLF") is performed on a hard disk, the disk's platters start out empty. That's the last time the platters will be empty for the life of the drive. If an LLF is done on a disk with data on it already, the data is permanently erased (save heroic data recovery measures which are sometimes possible).

If you've explored other areas of this material describing hard disks, you have learned that modern hard disks are much more precisely designed and built, and much more complicated than older disks. Older disks had the same number of sectors per track, and did not use dedicated controllers. It was necessary for the external controller to do the low-level format, and quite easy to describe the geometry of the drive to the controller so it could do the LLF. Newer disks use many complex internal structures, including zoned bit recording to put more sectors on the outer tracks than the inner ones, and embedded servo data to control the head actuator. They also transparently map out bad sectors. Due to this complexity, all modern hard disks are low-level formatted at the factory for the life of the drive. There's no way for the PC to do an LLF on a modern IDE/ATA or SCSI hard disk, and there's no reason to try to do so.

Older drives needed to be re-low-level-formatted occasionally because of the thermal expansion problems associated with using stepper motor actuators. Over time, the tracks on the platters would move relative to where the heads expected them to be, and errors would result. These could be corrected by doing a low-level format, rewriting the tracks in the new positions that the stepper motor moved the heads to. This is totally unnecessary with modern voice-coil-actuated hard disks.

More input from FAQ Farmers:

• The only time you could low level format a new voice coil hard drive if it you would have bad sector that are not being taken care by the hard disk logic. Most of the time you will have a utility to do this task that comes from the manufacturer of the drive and it will not work with any other brand. Maxtor and late quantum has a utility called Max blast plus and power max and others. They are used to diagnostic but also to fix at the low level.

• Those utilities can many times restore an unstable drive by reformatting at the low level and blocking out bad sector. Of course if the RLL (magnetic data) is low because the read write hardware is defective it will do no good. If the surface was damaged it could give the drive a new life.

• There is also an application called Spinrite (by Steve Gibson) It's not a low level format in itself but it reads and rewrites the data (at the low level) while analyzing the disk. Spinrite is over 17 years old and has been updated to the new technology ever since version 1 (current version is 6). I's a very respected software by all the hard disk service technician around the world. Steeve Gibson is one (if not the best) of the best hard disk low level white hat hacker in the world.

• No software of any sort can truly low-level format today's modern drives. The ability to low-level format hard drives was lost back in the early 1990's when disc surfaces began incorporating factory written "embedded servo data". If you have a very old drive that can truly be low-level reformatted, SpinRite v5.0 will do that for you ( But this is only possible on very old non-servo based MFM and RLL drives with capacities up to a few hundred megabytes. You can still read and write from that "so called" low level but not in the same way it was original;y possible then with old drives.

Answer 2

Low-Level formatting is used to outline areas (tracks and sectors) on the hard drive so physically the hard drive is ready to be used. So low level formatting is so called "PHYSICAL Formatting" which means all of your old data are physically wiped out and create a new structure on your disk. So when you add new data, it just add into your empty disk.

High level formatting is so called "LOGICAL Formatting" which means that all the old data in your disk will not be completely erased (they are still in your disk) but the access path to those data has been wiped out. So you cannot access those data anymore (e.g. access path is like your address book. when you lost the address book, you won't know where your friends stay and can't contact them (same analogy)) However, your disk will show as empty. Okay, again when you want to store new data in your disk, it will create new access path and replace old data with your newly stored data.

This formatting changes the file system on the hard drive so the Operating System that you use can write and save data to the hard drive.:)

Answer 3

Low level formatting: Normal formating our hard disk is Low level formatting, It will take Some minutes.

High Level Formatting: Quick formating our hard disk its takes some seconds.

Answer 4

The meaning of low level formatting is to remove all traces of data on a drive. This is a very lengthy process which goes sector by sector to completely clean the drive.