Date: Fri, 29 May 1998 16:16:18 -0400 (EDT) From: Simon Shapiro <shimon@simon-shapiro.org> To: tcobb <tcobb@staff.circle.net> Cc: "freebsd-scsi@freebsd.org" <freebsd-scsi@FreeBSD.ORG>, "freebsd-current@freebsd.org" <freebsd-current@FreeBSD.ORG>, Mike Smith <mike@smith.net.au> Subject: RE: DPT driver fails and panics with Degraded Array Message-ID: <XFMail.980529161618.shimon@simon-shapiro.org> In-Reply-To: <509A2986E5C5D111B7DD0060082F32A402FAC3@freya.circle.net>
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On 29-May-98 tcobb wrote:
...
> My problem report (most of which you snipped) pointed out a deficiency
> in the DPT driver code which renders it useless in HA applications. I
> believe that this deficiency is likely to be present in ALL VERSIONS of
> this code, unless suddenly, people are putting the newest code in the
> oldest versions of the OS.
We all trust that you use FreeBSD 3.0-current and a DPT controller in said
system. What you have failed to demonstrate is that the FreeBSD DRIVER is
at fault. I am very anxious to discover and repair ANY bug in this driver
as many people use this setup for mission critical work.
Since I read the driver code few times and am somewhat familiar with it, I
cannot find support to your claim that the failure you report (and we trust
there is a failure) is induced in the driver.
I am very interested in helping you solve your problem, but going into the
driver and tearing up the code, searching for unknown and unlikely breakage
is not an efficient use of my time and will most likely not advance our
common goal of getting your system up and running and the problem
eradicated.
As you can observe elsewhere, a FreeBSD SCSI HBA driver in general (and the
DPT driver in particular) is not involving itself with the contents of the
SCSI commands passed to it from the kernel. Nor does it concern itself
with the results of these commands.
In the FreeBSD driver, similar to other DPT drivers (but not identical), I
perfrom certain checks with the DPT hardware. These happen at boot time,
BEFORE any of the kernel boot prompts you see. None of these has anything
to do with what devices are attached to the bus, but strictly with the
controller; Who are you? How are you doing?, etc. But never anything to
do with attached devices.
Reporting an array size zero (or one) is most likely caused by the array
being DEAD, not degraded. Have you run the dptmgr verify function against
the entire array? DOS does not perform much analysis and can be misleading.
Unless you explicitly instruct the DPTMGR software to access data on a
disk (or array), only the first sector is being accessed. Thus, it is
entirely possible that the array is inaccessible beyond one sector, if that.
Your symptoms can be caused by many causes, all of them within the realm of
DPT hardware and attached devices.
I really do not know the purpose of your messages on this subject.
You really have not asked for help fixing the problem. Neither did you
offer any diagnistics data to me, or the group as a whole.
If your purpose is to create an acusation, it is well written, with the
minor flow of it being inaccurate and quite wrong in its conclusion.
If your purpose is to solve the problem, please send me the following (with
a copy to the group, if you care)
a. Exact Configuration; What CPU, what memory, DPT card model, type of
cache memory, amount of cache, exact firmware version, exact BIOS
version (NOT the same thing!) What disks are in which array, etc.
I'll also need to know how the disks are programmed into the array,
their bus and target IDs, etc. I need this information from both the
hardware configuration and the logical view screens.
b. Exact Setup; These disks, what brand and model? What firmware version
on each disk? How are these disks mounted and in what? The type of
cables you use, the type of terminators you use, etc.
c. Is the system bootable now? Is it on the net? Can I have a root login
on it for a while?
d. Are you going to be available to run dptmgr for me and be my eyes and
fingers, while in DOS or SU mode?
e. Have you run all the DPT diagnostics to assure that the arrays are
really healthy and accessible? Have you wiggled the wires to every
device, while the tests are running? Have you printed out the DPT error
log for the controller (from DPTMGR)? Have you run the statistics, to
see the error counts and rates?
Please provide me with this data, so I can try and help you.
Simon
---
Sincerely Yours,
Simon Shapiro Shimon@Simon-Shapiro.ORG
770.265.7340
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