Isolate the Bad/Good Sector on External Hard disk

[NhuZaa]

I want make two partition on external hard disk isolating the good and bad sectors can it be done. How ??

 

[kanewolf]

Could it be done, maybe. If the problem area is localized, you could figure out what the sectors are and avoid them. But, a disk that is starting to go bad will continue to degrade. If there is ever a doubt about a disk it should be destroyed so that data isn't lost.

 

[D_Know_WD]

Hi there NhuZaa,

I doubt that you will be able to create one partition with all the bad sectors and another one with the healthy ones. Also, as kanewolf said, you will not be able to isolate them and they will most probably continue to appear.
It seems that the HDD is unreliable and you need to get all the data stored on the drive off.

After that, I guess you could try to write zeros on it and re-test it with some tool that will provide a S.M.A.R.T. reports. This sometime could help a bit.

Cheers,
D_Know_WD

 

[Rookie_MIB]

Theoretically, it is quite possible **IF** you have the bad sectors localized in a particular spot.

What you would do is find the location of the sectors, calculate out the size of the free space -before- the bad spot, then create a partition starting at sector 1, going up to a few sectors before the bad spot. Then, create a secondary partition specifying a start sector a bit past the bad sectors going to the end. I think you would have to do this in Windows using the command line and diskpart utility.

Assuming that your external disk is disk 1 (VERIFY THIS BEFORE EXECUTING IT!! 'list disk' - then check and match up the size with the disk you have attached), and that your bad sectors are at 500mb on a 1tb drive

>select disk 1 (this selects the disk)
>clean (this erases all parition info)
>create partition primary size=450000 (this creates a primary partition of the size in megabytes. so 450GB == 450,000 MB)
>create partition primary size=450000 offset=505000000 (this creates second partition of size 450GB starting at 505GB, the offset is specd in KB, not MB or GB, hence the rather long number)
>assign (this assigns drive letters to the partitions and will pull up the 'do you want to format this drive' box.
>exit (exits the command line)

Now, I haven't tested this, but it gives you the basic idea on how it should work. Depending on your disk size and where the bad spots are located you will have to do the math to determine exactly where the bad sectors are. I would find an utilize a graphical disk check utility to help identify where the bad spots are to assist in doing the math. I will also caution you that a drive that is starting to show bad sectors should not be used to store any kind of important data as it can go from a few bad sectors to a bunch of bad sectors and an unreadable drive very quickly.

Let us know how this goes.

 

[HEXiT]

run chkdsk to map out any bad sectors. its what its designed for.
if chkdsk returns errors at the end then the disk is beyond repair.
so no matter how many partitions you try to make you will keep spreading bad sectors as its likely the drive head hitting the disk or burning the disk.
any other errors tend to be soft errors that can normally be formatted out.

there is 1 solution that will wipe the disk completely. a low level format. if you can find an app to do it (not many exist now) its worth a try as it will kill any soft errors on the disk and reset the allocation tables that windows uses to separate good sectors from bad.

 

[jsmithepa]

I want make two partition on external hard disk isolating the good and bad sectors can it be done. How ??

You are trying to do what the onboard firmware does automatically (block bad sectors so they are not used). This is something that a user usually don't concerned himself with.

But OK, if you still want to do this, and follow member's directions, you will end up with two driver letters, is that acceptable to you? Unless you are running a third party management software that "stitch" the now 2 physical partitions into one logical drive.

 

[Rookie_MIB]

I want make two partition on external hard disk isolating the good and bad sectors can it be done. How ??

You are trying to do what the onboard firmware does automatically (block bad sectors so they are not used). This is something that a user usually don't concerned himself with.

But OK, if you still want to do this, and follow member's directions, you will end up with two driver letters, is that acceptable to you? Unless you are running a third party management software that "stitch" the now 2 physical partitions into one logical drive.

If this weren't an external drive, but an internal drive, he could actually mount each individual drive letter under a directory instead of it's own logical drive in Windows (I know Win7 supports it). So - he could create a directory on the C drive like 'drive2', and then mount the two logical drives under those. Everything would show up then as a single drive (c) but would have access to all the storage capacity of the drives - much like how you can do it under linux.

I'm not sure if this would apply to a usb removable drive, but if Windows can remember which drive letter it assigns to a particular drive (which I'm pretty sure it does keep a list of recently attached drives), then it should also be able to remember to assign a mounted NTFS path assignment.

To access that, it's under 'control panel' -> 'administrative tools' -> 'computer management' -> 'storage' -> 'disk management',
right click the drive in question 'change letters and paths', this gets you to where those options are.