On 5/14/2011 10:18 AM, Louis-David Mitterrand wrote:

On Sat, May 14, 2011 at 10:03:44AM -0500, Stan Hoeppner wrote:

quoted

On 5/13/2011 3:29 PM, Louis-David Mitterrand wrote:

quoted

I've been having very bad performance with an LSISAS2008 controller
attached to 8 WD Caviar Black 1TB disks.

What is the nature of this 'very bad performance'?  Did you recently
upgrade kernel/driver and run into a regression?  If not, either the HBA
has developed a circuit defect, or the problem lies elsewhere, either a
backplane/cabling issue, or a drive going south.

The performance problem can be clearly attributed to that model of the
LSI card because with the Adaptec card and the same cables and disks the
problem disappears.

How have you ascertained this already?  As of 2 hours ago you still
don't have your filesystem(s) back up and running after the HBA swap.  I
would assume a backup restore of a few TB would take more than a few
hours...

The LSI card has always performed very poorly with all kernel versions I
tried, including the very latest, and the with most recent firmware
revisions from LSI.

LSI HBAs are usually held in pretty high regard.  Which specific part#
are we talking about?  Is this an OEM Dell HBA?

After bricking the card while trying to change its firmware to an "IT"
version (Initiatior Target i.e. non-raid) I had Dell send me a new one
on warranty and the performance problem remained.

You still haven't described the nature of the performance problem.  This
is a technical mailing list after all.

quoted

Do you have any log entries showing problems with the LSI HBA?  Drive
errors?  What does smartctl tell you about each drive?

No error. Just plain sloth.

Interesting technical description.  Now we have yet another post in the
Interwebs archives stating a certain piece of hardware is junk without
any real explanation as to the nature of the problem...

-- 
Stan