Drive Overlay Question

[Folkert Rienstra]

There should be no problems.

There will be if the overlay messed with the partiton table entries or
relocates the partition tables back and forth.

If you see four partitions the overlay is recognized.

An overlay isn't 'recognized', it is working or it isn't, it is needed
or it isn't. Depends on the type of overlay software in use.

If the volumes appear unformatted or corrupt, you have incorrect geometry.

In the partition bootrecords, not the MBR.
I'll bet that you won't find more than one partition if with incorrect geometry in the MBR.

 

[Liz]

My computer has failed and I have to replace the motherboard. Since the
hard drive is from the computer before last I am taking the opportunity to
install a new 120Gb drive. I want to retrieve data from the old drive if
possible but I'm not sure it will be possible.

If I install the old drive as a slave in the new PC will I be able to
access it?
The old drive has 4 partitions and an overlay. It's the overlay that has me
worried.

I don't understand how the overlay works, but wonder if the drive will be
readable if it isn't the boot drive.

Please help. There's hours and hours of work on that drive. Most of it
backed up but other bits I'd prefer to copy from the the old drive than
doing from scratch.

 

[Martin Williams]

You should be able to view the old drive just fine. If you were keeping
your drive as a master, then you might possibly run into some problems with
the overlay software. Sometimes those drivers can be difficult to remove.

If your computer doesn't recognize your old drive immediately, then go into
the BIOS setup and manually input the drive specifications so that it will
be recognized. Just write down the info on the disk label before installing
it.

 

[Eric Gisin]

There should be no problems. If you see four partitions the overlay is
recognized.

If the volumes appear unformatted or corrupt, you have incorrect geometry.
Never run chkdsk or Norton to fix this, correct the geometry.

 

[Folkert Rienstra]

My computer has failed and I have to replace the motherboard. Since the
hard drive is from the computer before last I am taking the opportunity to
install a new 120Gb drive. I want to retrieve data from the old drive if
possible but I'm not sure it will be possible.

If I install the old drive as a slave in the new PC will I be able to
access it?
Depends.
The old drive has 4 partitions and an overlay. It's the overlay that has me
worried.

I don't understand how the overlay works,

It is executed from/by the MBR bootcode.

but wonder if the drive will be readable if it isn't the boot drive.

Run a dos boot from floppy and see what you get.

 

[Folkert Rienstra]

You should be able to view the old drive just fine.

Not if this drive overlay does something to the partitition tables.

If you were keeping your drive as a master, then you might
possibly run into some problems with the overlay software.

Only if the bootoverlay downgrades the natural ability of the
bios instead of upgrading it.

Sometimes those drivers can be difficult to remove.

Running from a disaster recovery bootdiskette there is no such problem.
Just a Fdisk /mbr will remove it. But then access to the partitions may
also have been removed with some types of Boot Overlay.

 

[Svend Olaf Mikkelsen]

Not if this drive overlay does something to the partitition tables.

The operating systems behaviors in this matter are somewhat subtle,
but some Windows versions may show the partitions anyway. As far as I
remember as example Windows 2000 would show EZ-drive partitions, but
return the real MBR for a read to sector 0.

 

[Zvi Netiv]

My computer has failed and I have to replace the motherboard. Since the
hard drive is from the computer before last I am taking the opportunity to
install a new 120Gb drive. I want to retrieve data from the old drive if
possible but I'm not sure it will be possible.

You should be able to retrieve all your data and even use the old drive as slave
with your new motherboard, but it requires making some changes in the MBR.

Before we go on, note that acting on some of the advice that was given above may
harm your chances to recover the data!

If I install the old drive as a slave in the new PC will I be able to
access it?

It depends on the type of the overlay (there are two common overlay types,
EZ-bios, and Disk Manager from Ontrack, used by different disk producers), the
OS you will be using on your new system, and the configuration of your original
partitions (with the overlay).

If the overlay is EZ-bios, then the extended partitions may be accessible (not
guaranteed), but not the primary one (I suppose you have been running under Win
9x, otherwise you wouldn't use an overlay). If OTOH you had DM as overlay, then
none of your partitions will be accessible right away. Don't despair yet, as
the proper editing of the partition table will surface all your partitions.

The old drive has 4 partitions and an overlay. It's the overlay that has me
worried.

What should worry you now is how to *successfully* convert the overlayed
partition table into a "standard" one that is recognized by common OS (without
the overlay).

I don't understand how the overlay works, but wonder if the drive will be
readable if it isn't the boot drive.

There are tens of articles on the subject in google's archive but there is no
need to read them to conduct the conversion.

Please help. There's hours and hours of work on that drive. Most of it
backed up but other bits I'd prefer to copy from the the old drive than
doing from scratch.

Let's start by telling us which overlay you had, EZ-bios or Disk Manager. If
you don't know, then download RESQ from www.resq.co.il/resq.php, and use
RESQDISK to tell us what is the *first* partition type on that disk. If it's
type 84 then you had Disk Manager, and if type 85 then it's obviously EZ-bios.

Also, tell us what is the extended / additional partition(s) type.

For what will be coming next, converting an EZ-bios partition type into standard
is pretty simple. Converting DM is somewhat more complicated.

Regards, Zvi

 

[Liz]

Thanks to all those who have offered advice - I'm feeling a lot more
optimistic now.

I have the new PC up and running with a new drive so I'm almost ready to try
install the old drive as a slave.

Details:
Samsung 60Gb
Overlay is Disk Manager - On Track
Partitions:
C: FAT32
D: NTFS
E: NTFS
F: NTFS
OS: Win XP Pro

Thanks

Liz

 

[Zvi Netiv]

Thanks to all those who have offered advice - I'm feeling a lot more
optimistic now.

Don't place the wagon in front of the horses, and please answer in-line rather
than top-posting. This thread may become very technical and top-posting
irritates some people that could help you!

Also, please wide your right margin to 80 characters, to not wrap lines in
quoted text. Thank you.

I have the new PC up and running with a new drive so I'm almost ready to try
install the old drive as a slave.

Details:
Samsung 60Gb
Overlay is Disk Manager - On Track

The trickier of the two.

Partitions:
C: FAT32
D: NTFS
E: NTFS
F: NTFS
OS: Win XP Pro

I understand this is for the new drive. Did you have Windows 98 on the old
drive and then upgraded the OS? To what OS was the old drive upgraded, XP Pro
too? Does the old drive still have XP/W98 dual booting?

If affirmative for the last question, and all you need is copying some stuff
from your old drive then you may prefer the following course of action, rather
than converting the Disk Manager partition into standard one.

Connect the old drive as first (drive 0) and the new drive as second (drive 1).
Drive 1 (second) must be partitioned before doing this. Boot from drive 0. It
should start normally, *with* the overlay. The presence of the second drive may
cause the partition letters to change (see under computer management (local) /
storage / disk management (local). Copy what you need to your new 120 GB drive
and restore the configuration of the new drive as first.

You are now free to empty the 60 GB drive and use it as second.

If the above fails, then it's always possible to revert to plan B (converting
the DM partition to standard).

Regards, Zvi