A problem with harddrives

[melott]

I have a problem with harddrives & manufactures.

Generally when a drive has more than 10% bad blocks
the drive is considered bad. With the size of the
newer drives now ie. 20, 30, 50, or 150 gigs why
throw one out if there is still plenty of room for
what you are doing with it.
I have a 6 gig laptop drive and I only want to use
between 3 and 4 gigs. I keep most of my important
files backed up on CD.
So my question is ... is there a prg. that will scan
and mark the bad sections of a drive and allow you to
use the rest of the drive?? The beginning of the drive
where the BAM is is OK, It has some bad tracks toward
the middle of the drive.
I've tried 'MyFormat' but that doesn't seem to do the
job, it gets to a bad section and just hangs there.
With trial and error I can figure out which blocks are
bad and partition them as a bad partition.
It just seems a shame to throw out a drive when there
is still plenty of usable space.

[darksun9210]

i think HDtoolbox can do this, just big drives can take tiiiiime. i think it might blow away any data on the drive, but it should have sumfink loike "verify data blocks" as one of the first options when you run it. this should update the drives block listing to show any bad blocks as unusable to the drive.

other than that, if its a scsi drive and you have the access at work, i chucked a 4.3Gb into a unix station and it marked the bad blocks "out of service" actually on the HD itself. so that they were invisable to the computer just the drive adjusted its capacity to take into account the removal of these blocks. clever stuff. down by 300Mb, but still useable

other than that one of my 12Gb'ers i ripped out of a laptop as a dodgy section at the very begining of the drive and my A1200 wouldn't boot , so just havn't got it used in a partition but with 12Gb i'm not exactly gutted about 50Mb
might be a dell diagnostic partition or something.

[Karlos]

The older 3.1 HDToolbox had "verify blocks", but I think you had to manually mark regions with "modify bad block list" to set areas out of service.

Oddly, I haven't seen either of these options in later incarnations of HDToolbox.

[JaXanim]

I've used WorseFormat (it's on Aminet) to mark bad blocks and it works fine. Don't know what the partition limit is, but worth a look.

Cheers,

JaX

[Piru]

MyFormat or WorseFormat won't help with hard disks.

With modern hard drives there is no direct relation between logical and physical blocks, the damaged physical tracks and blocks get mapped elsewhere on the drive and the mapping is changed. From outside ("from the interface") nothing appears to have changed on the drive.

What MyFormat and WorseFormat do, is to format each block, and mark bad blocks/tracks (that won't format properly) "allocated" in the FFS bitmap, so FFS won't reuse the blocks, ever. This works pretty well with floppies where logical and physical mapping always remain the same (there is no magic mapping done by the media).

However, it will not work with modern hard drives that map the blocks automagic. When errors occur, the physical blocks/track will be relocated to specially reserved backup area, and the logical->physical mapping is changed. After this, the previously "damaged" area is perfectly working again. In fact, hard drives do speculative mapping too, they use fuzzy logic to predict which parts of the disk are likely to fail "soon", and map the contents out of the way even before any damage happens. Likewise, if some part of the disk only works after several attempts, the block/track might get relocated.

Now if you use MyFormat or WorseFormat to scan the disk for these bad blocks, you most likely will end up with a disk that has perfectly working areas marked as "bad".


The "Badblock list" in old HDToolBox is totally unrelated to method used in MyFormat and WorseFormat. It's list of the actual physically bad areas on the disk. However, since modern drives hide this information "from the interface" competely (the list always appears empty), and do the mapping internally, this feature was removed. The drives do the bad block mapping automagic, and without ever telling it to the OS using the disk (except perhaps thru SMART).


In short: If the hard disk has enough errors for them to appear to outside of the drive itself, it means the disk is toast. Get it RMAd if still under warranty or dispose it.

[iMacMiga]

I have a 10GB Hard disk on my A1200 that is totally trashed from about 7.6GB onwards but the first 7.5GB is fine (i allow a margin for safety). I just set the RDB on the drive in HDToolbox to 7250 cylinders instead of 9765 so it doesn't consider the damaged upper part of the drive to be part of the drive surface.

If you can figure out if the bad blocks are in a cluster or spread out you might be able to use some of the disk, but I don't advise it. If the bad blocks are occurring spontaneously on the drive ditch it fast.

I only continue to use mine becuase the damage was caused by the computer it was attached to, not the drive itself degrading.

[KennyR]

Please, don't trust a drive with bad blocks anyway. It's a disaster waiting to happen. As soon as a drive starts to act up in any way, bad blocks, errors, vibration, noise, then its not trustworthy and needs replaced. Bad blocks have a habit of breeding until they're all over the place. Any data you put on a bad drive is probably doomed.

[melott]

This 6.5 gig drive .... it has 2 bad spots.
The first bad spot is about 200 megs in and about
30 megs long. The second is at about 3 gigs in and
again about 30 megs long.
I don't know what happened to cause this problem
but it seems a shame to throw it away when so much
of the drive is still usable. I have figured this
out by watching 'MyFormat' where it hangs-up.
I can partition these bad spots and just not use
them but it seem to me there should be a way to
just mark the bad spots and not include them in
a format. WorseFormat sais it does that and unless
you do a total reformat on the drive the bad block
list should survive (I think).
But then I don't know for sure (only guessing)
 

[Piru]

WorseFormat sais it does that and unless you do a total reformat on the drive the bad block list should survive (I think).

WorseFormat has nothing to do with hard disk badblock list. It does not read it, or manipulate it. Even full format won't erase the drive badblock list.

Back in the days low level format was possible (and recommended in some rare cases), it would also erase the bad block list. Modern drives don't allow low level format, nor they have any "external" badblock list to erase anyway. The information is all kept and managed internal to the drive.

[pVC]

Don't know about those modern drives, but I used to use years ago smallish hd, which had some bad blocks. I used ABTools to mark them out of use. In fact ABTools makes one file visible on filesystem, which lays over bad blocks. So the drive works if you don't remove that file or reorg or something. Downside is that ABTools works only with original FFS.. that means that there's that usual 2/4G limit in partition/hd size. With one bigger drive I just didn't use the area where I found the bad blocks to be. Just left it without any partitions.

[melott]

@PIRU....
I was refering to the list created by WorseFormat
not the internal BadBlock list created by the drive itself.

BTW is there a prg. that lets you look at the BadBlock
list ?? I'm interested now and would like to see if its
full or what.

@pVC
I'm going to check ABTools out if its on Aminet.
I'm using FFS and I don't like partitions larger
than 2 gigs. Usually 1 gig or less.

[pVC]

ABTools (AmiBackTools) is/was commercial... although I have feeling that it was on some mag's coverdisk once.

[melott]

@pVC

The update patches are on Aminet but not the prg.

I probably have it, I ran a BBS many years ago and
have hunderds of disks that I haven't looked at in
years. If I get ambishious I'll look for it.
Could take hours to go through the disks.

[melott]

@pVC

The update patches are on Aminet but not the prg.

I probably have it, I ran a BBS many years ago and
have hunderds of disks that I haven't looked at in
years. If I get ambishious I'll look for it.
Could take hours to go through the disks.