Very weird disk parttion error

[puffingbear]

I have a 2k server that has the weirdest problem.
According to the user it blue-screened, on reboot it reported ntldr is missing.

On using ERD Commander to boot the dead system, the 2 disk partitions on its RAID 5 array have swapped positions.
It reports the Primary NTFS partition as being at the end of the disk and the Extended partition with NTFS Logical drive as being at the beginning.
It still shows the Primary partition as being the "Active" one. The letters C: and D: have swapped also.

It seems that only some files are missing from the system partiton, e.g. ntldr is gone, io.sys is still there.

The RAID array points out no problems and I can read the data with ERD to copy it over the network.
I cannot access the SYSVOL however, i get mixed messages of "access denied" "location not found" and of it just being empty.

I'm really puzzled how such a thing could happen from a crash, and as how to fix it.

Thanks for reading thru all that, any ideas?

 

[Seaspray0]

Very possible. It could have occured during the following condition... A hard drive was originally partitioned with a fraction of the space available. After the OS was installed, a second primary partition was created. At some point, the OS was transfered or recreated to this second primary partition and made the active partition. When the computer rebooted, it boots from the active partition (now the second primay partition) which shows up as C drive. The first primary partition got deleted at some point and recreated as a secondary partition.

possibility 2- some computers bios do not contain all the utilities on the bios chip. The bios contains the required information and the utilities are loaded onto a primary partition on the hard drive (typically a small primary partition). When you enter bios settup, the computer reboots to this partition to allow you to use utilities put there. This is common occurence with compaq servers and some of their other computers.

possibility 3- If the partitions are of equal size, mirroring may have been done through the OS. An error has occured on the first partition.

Note: a basic disk can contain up to 4 primary partitions or 3 primary partitions and a secondary partition. This can be useful in test environments because you can load 4 operating systems onto the disk and by selecting which one is active, you can select which partition is recognized as the C drive and boots to it.

 

[puffingbear]

Thanks for the post, I was clearly a bit vague as I'm aware of the conditions you describe but they cannot have occurred in this scenario.
To be more exact the server has 5 36Gb SCSI HDDs in a RAID 5 array giving a total of 140 (ish) Gb.
The "drive" is split into one 40gb system & boot partition and one "data" partition of 100Gb.


The server was functioning perfectly with its 2 partitions. It then crashed.
On booting it up (with recovery tools) the Primary partition had transformed into an Extended Partition with Logical Drive.
The Logical Drive had in turn become a Primary partition.

I have made some headway with this problem now, I've used Volume Manager to return the partitions to their original state.
I was really looking to see if other Server Managers had experienced anything like this when using a similar RAID system.



Note: You cannot merely choose which drive is active as a means of negating a boot loader. Not all OSes will boot to partitions that cross the 1024 cylinder boundary, and not all OSes are comfortable with more than one Primary partition.