kernel: ciss0: *** SCSI bus speed downshifted, SCSI port

[RA Cohen]

I'm new to this list but probably should have joined several years ago. 
I'm an independent consultant and I have placed many off-lease Proliants 
(lately DL 360 and 380 G3's) in the field running FBSD.

They are generally problem free, but I've had one recent case that still 
puzzles me:

I had a large ML 530 G2 in service populated with 36 gb drives, in the 
same server room as 2 DL380 G3's. I train my clients to observe the 
drive lights daily if possible. One morning the client noticed one drive 
on the ML530 showing red, and two drives on one of the DL380's as red 
(this server was build with two mirrored drives (for os) in one array, 
and the remaining 4 striped drives (for data) in the other). The third 
server was normal with no failed drives. I replaced the drive on the 
530, the array rebuilt and all was and continues to be, well. Not so for 
the DL380. The failed drives were each part of different arrays, that 
was good I thought. They were replaced, the array rebuilt, and we had 
six green drives. Until the next day when there were one or two failures 
- different drives - I kept playing around shuffling drives (at this 
point I knew I had to rebuild the machine and we had very good tape 
backups thanks to bacula and SDLT drive). The arrays would rebuild, but 
as soon as almost all the data was restored the array would fail. Long 
story short, I concluded there were environmental problems that caused 
the original failures, my feeling was there very well could be damage to 
the embedded 5i SCSI controller.

The server was replaced with a new (used) DL380 G3 and all seems ok 
until this morning (about a week after replacement) when I see this in 
the log:

Jun 17 18:03:16 dodson1 kernel: ciss0: *** SCSI bus speed downshifted, 
SCSI port 2
Jun 17 18:08:21 dodson1 kernel: ciss0: *** SCSI bus speed downshifted, 
SCSI port 2

I've google'd and searched for this kind of message and am still unsure 
what it means exactly. Does the bus downshift in reaction to a specific 
problem and then upshift? Or is there a problem lurking waiting to rear 
its ugly head? I'm also uneducated as to HP/Compaq's pro-active drive 
monitoring that is integral to these servers.

I wish there were a comprehensive summary of hardware-related messages 
for FreeBSD on Proliants. The two seem to go together quite well in most 
situations.

Thanks in advance for any and all help,
-Roy

-- 
Roy A Cohen
Network Advantage LLC
www.net-vantage.com
413.223.9007
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