Jason Costomiris ([EMAIL PROTECTED]) thought it appropriate to state: >> I found a statement in the december RedHat (4.1?) >> claiming that some, but not all Adaptec have problems >> since 2.0.12. > >Hogwash.
To set the record straight: it´s in RedHat 4.0, in the unsupported i386 images section. It states that their bootimage kernel (dunno which version) had problems with some Adaptec aic7xxx cards, and that they created another image using the aic7xxx driver from 2.0.12. Fact: I am, right now, running a 2.0.27 patched with the drivers/scsi from 2.0.11. The system runs w/o problems. It did not run with the regular 2.0.27, 2.0.25, 2.0.28, 2.1.15, 2.1.16. Dunno about 2.0.29. >I've got 9 or 10 of these cards deployed. All of the machines are running >2.0.29 without a single problem. I've never done anything more than plug >the card in, turn the machine on and install. No special tweaking >required. So you´re lucky. Somewhere between 2.0.11 and 2.0.25, a change in the aic7xxx driver has happened. From the looks of it, the aic7xxx insists on accessing a wide scsi disk (IBM DORS, in my case) with 20 MHz scsi-2. This fails, and the system gets stuck in an loop of negotiating, aborting, reseting. The Adaptec BIOS is v1.23, 1996. There might be a problem with cable and/or termination. I have read that Adaptec boards are a bit picky in this regard. The 16bit cable is from the kit, but the 8bit bus (having been in operation since 1994, with ISA Adaptec 1542, Asus on-board NCR, and PCI NCR SC200) has seven SCSI devices and might be a bit long. With "Automatic" termination selected, low byte termination is reported as disabled, high byte is reported as enabled. Fits page 1-7 of the manual. Nonetheless I will check termination once more as soon as I have done all the other stuff that kept piling up during the last two days. The earlier kernel accesses the disk with 10MHz no problem. So if there´s a hardware flaw, the aic7xxx driver might as well use the lower frequency as a fallback. I would have settled for half the bandwidth any time during the last days. If Adaptec tolerance for cables is indeed substandard, this fallback might be worth changing the driver once more. Hope that those who might encounter a similar problem will find this summary helpful. You will probably not be able to use the older aic7xxx with 2.1.x, I suspect. b. P.S.: my gratitude to those maintaining the aic7xxx. I have read claims during the last two days that Adaptec does not support Linux in any regard. The 2940, 2940U and 2940UW boards I have dealt with during the last years were okay, however, this particular one will be the first and last one I bought myself. There are alternatives (see e.g. http://www.covd.se/~mikn/linux/aha/aic7xxx.html).