bgodden
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Need help determining proper SCSI bus termination
Hi,
I have an Intel VS440FX with an Adaptec 2940 card attached and am having some problems installing Linux (I had Windows on this machine previously). The problem I am seeing is that during the install of Linux(RH 6.0 from CDROM), after the packages have been scanned (supposedly successfully) and the drive has been partitioned, the installer begins to add packages, then it chokes saying it can't find certain rpms and that they don't exist. I had installed onto this machine before, but have changed the hard drive since.
Here is the configuration:
AHA 2940(S76) PCI SCSI Adapter, says w/ AUTO on the card, which I assume means Auto termination...
Next on the chain is a Seagate Medalist 9140 SCSI 2 Drive. (ST34520N). SCSI ID 0, The default SCSI configuration was "Enable SCSI Terminator" - ON, and "Drive supplies term. power for it's own terminators only" - ON. This default configuration is not working... I have also adjusted the CDROM drive as below.
This drive can also be configured to supply term power to SCSI bus only, to both the disk and the SCSI bus, or Neither.
The CDROM drive (Toshiba X-5701TA SCSI) is last in the chain and by default has SCSI ID 1 and the TERM OFF.
I've checked the card an don't see any jumpers where I can change settings on it. I've changed the setting for both drives in a few different ways, but still end up with the same errors during install.
I cold make a table and figure the right configuration eventually, but I thought it would be a good question to pose as well as I' hoping to gain a better undertanding of why this isn't working and why it will, etc. instead of just getting the right combo setup.
Hopefully this explanation is good, if this question gets any hairier, I'll add more points for the help.
Thanks!
I have an Intel VS440FX with an Adaptec 2940 card attached and am having some problems installing Linux (I had Windows on this machine previously). The problem I am seeing is that during the install of Linux(RH 6.0 from CDROM), after the packages have been scanned (supposedly successfully) and the drive has been partitioned, the installer begins to add packages, then it chokes saying it can't find certain rpms and that they don't exist. I had installed onto this machine before, but have changed the hard drive since.
Here is the configuration:
AHA 2940(S76) PCI SCSI Adapter, says w/ AUTO on the card, which I assume means Auto termination...
Next on the chain is a Seagate Medalist 9140 SCSI 2 Drive. (ST34520N). SCSI ID 0, The default SCSI configuration was "Enable SCSI Terminator" - ON, and "Drive supplies term. power for it's own terminators only" - ON. This default configuration is not working... I have also adjusted the CDROM drive as below.
This drive can also be configured to supply term power to SCSI bus only, to both the disk and the SCSI bus, or Neither.
The CDROM drive (Toshiba X-5701TA SCSI) is last in the chain and by default has SCSI ID 1 and the TERM OFF.
I've checked the card an don't see any jumpers where I can change settings on it. I've changed the setting for both drives in a few different ways, but still end up with the same errors during install.
I cold make a table and figure the right configuration eventually, but I thought it would be a good question to pose as well as I' hoping to gain a better undertanding of why this isn't working and why it will, etc. instead of just getting the right combo setup.
Hopefully this explanation is good, if this question gets any hairier, I'll add more points for the help.
Thanks!
Okay, sounds straight forward, but let me recap to be sure I've got it right.
The SCSI cable goes from the 2940 to the disk drive then to the CD (which is the last thing on the SCSI cable). Currently the disk has its TERM and TERM PWR jumpers installed and the CD has its TERM jumper removed.
This would be exactly backwards. the CD, being the last device on the bus needs its TERM jumper in to enable its terminators and the disk needs its TERM jumper removed. With the disk's TERM jumper out the TERM PWR jumper doesn't matter, leave it in.
The other way to correct the problem would be just to change the order of the devices. If you make the disk be the last device on the SCSI bus you don't have to fiddle with the jumpers.
The basic rule is that each SCSI bus may only have terminator, and that terminator must be at the end of the chain. The terminator can be in a drive, as is normally the case for internal drives. Or it can be an external terminator attached to the last device, as is frequently done with external SCSI devices. Note that if you were to attach an external device or devices to the 2940, that SCSI bus would have to be terminated. It and the internal SCSI bus are different.
The 2940 has the option of allowing automatic termination of it's external connector. When set to "Auto" it senses the presence of an external device and disables it's on-board terminator for the external bus. Most of the time this works fine, but occasionally you'll encounter a external device that won't trigger the 2940 to disable the terminator and you have to force that function "Off". If there aren't any external devices connected the 2940 must be configured for either "Auto" or "On" termination.
One other consideration. Some CD drives don't properly negogiate the max SCSI bus transfer rate properly. I don't remember if this particular one has that problem. Usually you want max possible speed enabled in the 2940's bios for the disk drives and set the max to 10 for CD's and tapes.
The SCSI cable goes from the 2940 to the disk drive then to the CD (which is the last thing on the SCSI cable). Currently the disk has its TERM and TERM PWR jumpers installed and the CD has its TERM jumper removed.
This would be exactly backwards. the CD, being the last device on the bus needs its TERM jumper in to enable its terminators and the disk needs its TERM jumper removed. With the disk's TERM jumper out the TERM PWR jumper doesn't matter, leave it in.
The other way to correct the problem would be just to change the order of the devices. If you make the disk be the last device on the SCSI bus you don't have to fiddle with the jumpers.
The basic rule is that each SCSI bus may only have terminator, and that terminator must be at the end of the chain. The terminator can be in a drive, as is normally the case for internal drives. Or it can be an external terminator attached to the last device, as is frequently done with external SCSI devices. Note that if you were to attach an external device or devices to the 2940, that SCSI bus would have to be terminated. It and the internal SCSI bus are different.
The 2940 has the option of allowing automatic termination of it's external connector. When set to "Auto" it senses the presence of an external device and disables it's on-board terminator for the external bus. Most of the time this works fine, but occasionally you'll encounter a external device that won't trigger the 2940 to disable the terminator and you have to force that function "Off". If there aren't any external devices connected the 2940 must be configured for either "Auto" or "On" termination.
One other consideration. Some CD drives don't properly negogiate the max SCSI bus transfer rate properly. I don't remember if this particular one has that problem. Usually you want max possible speed enabled in the 2940's bios for the disk drives and set the max to 10 for CD's and tapes.
ASKER
Hmmm... OK, so it looks like I was understanding this better than I thought :-) I've tried most of these configurations and it looks like the SCSI ID is fine on the Controller as well as termiantion is enabled there... I have tried different orders of the devices, but with the same results. So this is the current configuration:
The Hard drive is the first device on the cable and it has it's term turned off (I have the jumper parked. And I also set the Term Power to the "Neither" setting.
The CDROM is the last in the chain and it has it's term enabled.
So as far as hardware setup goes, there is one last thing I'm not exactly sure about. On the hard drive, should the term power be set to Drive supplies term. "supply power for it's own terminators only" , "supply term power to SCSI bus only", to both the disk and the SCSI bus, or Neither.
Also, I was watching the install closely this time and the CDROM is being accessed normally between rpm installs and then seems to drop into the pattern of initializing and then the install dies.
The Hard drive is the first device on the cable and it has it's term turned off (I have the jumper parked. And I also set the Term Power to the "Neither" setting.
The CDROM is the last in the chain and it has it's term enabled.
So as far as hardware setup goes, there is one last thing I'm not exactly sure about. On the hard drive, should the term power be set to Drive supplies term. "supply power for it's own terminators only" , "supply term power to SCSI bus only", to both the disk and the SCSI bus, or Neither.
Also, I was watching the install closely this time and the CDROM is being accessed normally between rpm installs and then seems to drop into the pattern of initializing and then the install dies.
I believe that the Adaptec Controller will supply the termination power for the drives.
as per the above comment, termination is at both ends of the chain only:
adaptec controller scsi id 7 (default) terminated (or auto per the Adaptec bios)
seagate HD scsi id 0, not terminated (w/0 termination the power issue
for termination should not matter
toshiba cd scsi id 1, terminated
as per the above comment, termination is at both ends of the chain only:
adaptec controller scsi id 7 (default) terminated (or auto per the Adaptec bios)
seagate HD scsi id 0, not terminated (w/0 termination the power issue
for termination should not matter
toshiba cd scsi id 1, terminated
ASKER
Right, this is how the config is setup. I have confirmed these settings in the SCSI BIOS and also made sure that the data transfer rates are set to max (which is 10).
Tried again, no dice. Another tidbit is that the installers doesn't always die in the same place, but there are a few re-occuring places. Don't know if that would be a useful clue.
Tried again, no dice. Another tidbit is that the installers doesn't always die in the same place, but there are a few re-occuring places. Don't know if that would be a useful clue.
Okay, the SCSI bus is now correct and shouldn't be a source of the problem.
Next most likely source of the problem would be a bad CD or a bad CD drive. I'd try another CD first, preferably one from a "boxed distribution". If that doesn't help, see if you can borrow a drive to comapre results.
Next most likely source of the problem would be a bad CD or a bad CD drive. I'd try another CD first, preferably one from a "boxed distribution". If that doesn't help, see if you can borrow a drive to comapre results.
ASKER
Right. It is a boxed version, and I have used it before. I'm suspecting the drive at this point, I did try a FreeBSD install last night and iut choked aswell hmmm... I'll try a different drive.
Just out of courosity, the final BIOS for this mainboard was 18, it might wb worthwhile to flash it if you haven't done so:
http://support.intel.com/support/motherboards/desktop/vs440fx/software.htm
bill
http://support.intel.com/support/motherboards/desktop/vs440fx/software.htm
bill
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ASKER
Hmmm... Well it didn't seem to turn out to be a flaky drive or CD. I tried two different SCSI CDROM's with the same result, then went to a IDE CDROM drive and it worked like a charm. Perhaps a BIOS upgrade might help the scsi bus be a little less flaky or whatever was causing this failure.
I appreciate all the great help! jlevie help me the most through this problem from start to finish (this started with another question).
Thanks!
I appreciate all the great help! jlevie help me the most through this problem from start to finish (this started with another question).
Thanks!
You might also want to check out Adaptec's site (www.adaptec.com). I just fought a problem all day yesterday that turned out to be the bios on my 2940UW card. The latest firmware flashed onto the card fixed it.
ASKER
OK Thanks. I did change the card at some point, but essentially used the same card. Could be that firmware for all of the hardware is needing the latest... Thanks for your help!
According to how old your card is some require the boot hard disk to be set at ID 0. New one will boot any ID number.
The card is the first in the chain so it must be terminated. Your CDrom is the last in the chain so it also must be terminated.
Make sure your Bios is set to No drives installed.
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Good Luck