IBM NETFINITY 5600 BOOT PROBLEM ! ! !

[paulopadrao]

Hi i have one problem, most of the time when i a, booting the server on the morning i get this error "1962 Drive does not contain a valid boot record" . This server don´t have any RAID controller . I have 4 drives on the tower, witch are controlled by the internal SCSI AIC 78xx. The hard disks are installed on the folowing order :
1- Boot disk ID-0
2- Disk 2 ID-2
3- Disk 3 ID-4
2- Disk 4 ID-8

What i seen is when the server starts founding the disks on this order the system always starts ok.

But most of the times it start from the last disk and change the SCSI IDS .
So it will be like that.
1- Disk 1 ID-9
2- Disk 2 ID-5
3- Disk 3 ID-4
2- Disk 4 ID-3.
Why is the sever changing the scsi scanning order ???
Is there any think i can change on the controller?
Let remind again if the server starts scanning the disks from the top to down it will boot ok, cause the windows nt is isnttaled on the first disk .When he starts from down to up it will not boot . So i keep retarting until he remenber the correct order .

Any ideas
Many thanks
Paulo Azevedo

 

[scsiraid]

I assume these are Hotswap drives. Check both ends of the non-SCSI cables plugging to the backplane. Backplanes have option bits which change the addressing order and base address. This is to handle the difference in order between rack and tower boxes that share the same backplane p/n. Im betting that the 'forward/reverse' bit is flaky and is changing personality between rack and tower and messing up the drive ordering. If the cables are ok, the backplane may be bad.

 

[paulopadrao]

Yes they are Hotswap drives the first 3 are the same kind,but the last one as 17 Gb.
The strange think is when he gets the corrected start order, i can restart the server many times that will always start ok .
But on the next day i get the same problem. Is there any battery to change or check. You had speak about the 'forward/reverse' bit is change. Where i configure the server to start as Tower or Rack ??