rx4640 Poor SCSI backplane HDD connection (survey)

[Bryan Strait]

Hi,

Has any rx4640 users had problems getting the system (EFI) to recognize drives in the SCSI bays?

We have to remove drives from the bays from time to time and occasionally have been running into problems where the HD lights are green and the system will not boot because it is unable to find the drive from which to boot. In this state, if attempting to add a new boot entry through EFI, the HD boot entries are not available. Powering off the system and reseating the drive seems to do the trick. It seems the rx4640 drive bay does not make a secure connection to the SCSI backplane when using the simple lever-latch system described in the operations manual. I took the front panels off and noticed that the connector on the back of the HD carrier does not always make a complete connection to the backplane. An additional wiggle and push beyond the latching is required to make a full connection. I've seen this on multiple rx4640 systems. Anyone else?

I haven't tried this enough to conclusively determine it's a backplane connectivity problem. Could it also be an issue with the SCSI bus? Is the SCSI bus live when the system is in the off state? Btw, we never perform hot-swaps with these drives.

Thanks ahead for your input.

Bryan

[mits]

Hi,

The best approach for resolving your problem is that you will report your problem to HP support center and request them a root cause analysis. If you have seen the same problem with multiple systems, it is better you will clarify which disk drive was used for which system when the problem happened. You may have some bent pins with a specific disk drive and it may caused your multiple problem.

[Steven Bearden]

Bryan,

We have two rx4640 with 2 local SCSI hard drives each (one of each which is the boot drive) and haven't had any problems at all since I installed and them them running last August (2005).

Let me know if I can be of any other help.

Steven

[Alan_152 · Accepted solution]

I would bet that the issue is not in the bays itself -- but instead in the cabling from the bay master to the controller card in private slot 1, or it is the card itself. Current models of the 4640 use either the A7173A or the SA6402, depending on whether you have hardware raid or not.

Also, when you put new drives in an EFI-equipped unit, you'll want to get to an EFI prompt and type in "reconnect -r" to be sure that the new drive is detected. If it is at that point, then you'll want to make sure that your system firmware recipies are u p to date, and that the drive ECU firmware is also up to date.

We have about 15 of the 4640s at this lab, all the way from pre-production prototypes to the most current models. As much as we abuse these units, the drive bays are generally the least of our concerns. The HP-style slides/connectors for the U160/U320 interfaces are pretty standard across all the lower-end Integrity equipment that HP sells.

[Bryan Strait]

Thanks for the responses so far.

I have not been entering the reconnect command but rather removing the boot entry and adding a new one, selecting the same entry from the list of bootable devices. In the cases where the drive has been unrecognizeable, you cannot see the drive in the list of bootable devices. Next time the problem occurs, I'll try the "reconnect -r" and see if it then shows up in the list.

I believe the 2 machines of we've seen the problem are using the A7173A. The last I checked, the SCSI cabling from the card to the backplanes on these machines looked okay.

Interested in more responses. Thanks again.

[Alan_152]

Make sure that the firmware on the 7173 is up to date, also.