Keep losing disk partition

  • Thread starter Thread starter Tony Gravagno
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Tony Gravagno

I have one hard drive on my laptop which has three primary partitions
and one extended. The primaries are structured like this:
0 - misc data
1 - boot/XP primary
2 - boot/XP secondary

I use the primary partition for long term MSDN development and the
secondary for testing and blowing away as required. I use System
Commander for booting into these partitions.

I used to have a Win98 partition in volume 0 but I removed it to
reinstall as part of my normal development activity. The problem is
that I can never get volume/partition 1 to consistently recognize and
access that partition 0.

Rather than leaving it all up to System Commander to partition, I
deleted the partition 0 and recreated it from XP Computer Management,
Disk Management. It read Healthy, I formatted it, assigned a letter,
and I was using it for hours. When I rebooted the system I could no
longer see the partition 0 from Windows Explorer, though Disk
Management still shows it there as a Healthy (Unknown Partition).
Right clicking the partition shows the famous Delete Partition option
with all others disabled.

I see this issue come up in newsgroups a lot, but without a solid
reason or solution. What's going on in there? What do I need to do
to "lock" the partition in place so that it doesn't go Unknown?

Short of blowing away partitions 1 and 2 I'll be happy to try some
experiments to get this figured out.

Thanks.
Tony
(using MSDN no-spam alias)
 
Something similar happened to me about 1 year ago. A partition that I had
been using daily, for more that a year, all of a sudden disappeared. It was
shown in disk management as "RAW". Many others have had this happen. I have
never seen any good answers as to why this happens, or what a person can do
to prevent it from occurring!

I was able to recover everything by using EasyRecovery Professional so I was
only out my time spent. The partition has functioned flawlessly ever since.

An acquaintance had partition C" through J: - across 4 different drives. One
day, when he went to shut down the computer, he said that upon clicking on
the "shutdown" button, the computer immediately powered off. It did not go
through the 15 second, or so, normal shutdown. Upon restarting his computer
he found that he had lost partitions D: through J:. They were all listed as
"RAW"!

This is something that has to be solved, and soon! There are too many people
posting with this type of experience!

--
Regards:

Richard Urban

aka Crusty (-: Old B@stard :-)
 
This problem usually occurs because of a cache-coherency error
on the Hard Disk that occurs during shutdown.

At shutdown, Windows is *supposed* to tell the Hard Disk to turn
off write-caching so that all the shutdown-housekeeping is properly
written to the Hard Disk before the power is removed.

However, if Windows thinks the write-caching has been disabled
and the drive is still working with write-caching enabled, then the
critical housekeeping data at shutdown may not be properly
written to the hard disk before the power is removed. Depending
upon the information left in the write-cache, this could be as simple
as a few lost-clusters to something as serious as partition-table or
FAT corruption.

"Raw" partitions are caused by corrupting the partition-table and/or
the FAT in such a way that Windows does not "see" the drive as a
validly-formatted item. Windows then blindly offers to format the
drive (it's trying to be helpful). If you follow this advice, your data
is probably unrecoverable.

There is some third-party software that can analyze a damaged
disk and rebuild the partition-table and FAT/NTFS file structures.
This software can *sometimes* revive a thrashed disk.


Things to check:

1. Ensure the Hard Disk you are using has recent firmware. In
some cases, you will have to contact the technical support
department of your Hard Disk manufacturer and pound-the-desk
rather vehemently before they send you a replacement disk with
proper firmware.

It is common for disk manufacturers to try and blame this
problem on disk-drivers and/or OS interactions. In some cases
that is true. In others, the disk firmware needs to properly
accept instructions from Windows to disable its write-caching
algorithms when Windows tells it to.

2. Ensure you are running the latest Service Packs for your OS.
There have been a bunch of fixes to the disk-drivers and the OS
to try and improve the "bulletproofing" of the shutdown-procedure.
It is possible that one of these bugfixes may be relevant for your
particular hardware/chipset configuration.

3. Ensure the version of System Commander you are using is W2K
and/or WXP-smart. If System Commander is performing some
partition-renaming operations at shutdown and is not properly
working in write-through (no caching) mode -- this will certainly
leave you with invalid partition-configuration data on the platters.



Best I can do for now. <tm>


Bill
 
Went through all of that, many times. The only thing "common" to my computer
(one drive going RAW) and my acquaintances computer (three drives going RAW)
is that we both use W.D. hard drives. We both had all the current service
packs, updates and motherboard drivers available at the time. In my
acquaintances situation, he knew that there was a problem the instant he
clicked on shutdown. You don't go from clicking "shutdown" to a power off
state in 1/2 second, as his computer did!

Since the incidents, neither of us has had any further issues.

--
Regards:

Richard Urban

aka Crusty (-: Old B@stard :-)
 
Thanks for the comments guys. I have made three errors here:
1) System Commander has a feature to hide partitions. Even though I
had deleted and recreated a partition through the XP Disk Manager, SC
still had the setting that said to hide partition 0 from the others.
As soon as I caught this everything is now fine. Answer: It's not
what you set now, it's what might have been set earlier.
2) This group is not moderated via MSDN as I thought.
3) I used the wrong alias address for MSDN anyway. Doh!

Ultimate resolution, the answers we seek are frequently closer than
they seem. :)

For reference, I'm using the partition in question now as a backup
staging area, from which I will generate CDs for our development
systems. Hearing about situations where entire partitions simply go
Raw is enough to scare someone into taking immediate measures to
insure full backups for all critical data - something we should all
practice on a regular basis anyway.

Regards,
Tony
 
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