Very slow I/O performance on HP BL465c

[Scott Lambert]

> Nathan Le Nevez wrote:
> > I?m fairly certain this is a hardware problem ? swapping the disks from
> > a known working install on another blade produced the same lousy
> > performance.
> 
> >>>> Hi,
> >>>>
> >>>> I'm running 7.2-p3 on 2x HP BL465c blade servers, one of which
> >>>> performs very poorly. Both have the same RAID controller and 2 x
> >>>> 146GB 10k SAS disks configured in RAID-1. Both controllers have
> >>>> write-cache enabled. Both servers are running the same BIOS and
> >>>> firmware versions. Neither servers are running any services other
> >>>> than sshd.
> >>>> 
> >>>> Blade with good performance (2 x Opteron 2218, 8GB RAM):
> >>>> 
> >>>> Blade with bad performance (2 x Opteron 2352, 16GB RAM):
> >>>> 
> >>>> # dbench -t 10  1              2              3             4
> >>>> blade1          183.456 MB/sec 236.86 MB/sec  299.28 MB/sec 192.675 MB/sec
> >>>> blade2          6.97931 MB/sec 9.42293 MB/sec 10.2482 MB/sec 12.407 MB/sec

Sorry, I deleted the start of this thread.  

I figured someone else would suggest pulling half the RAM in the slow
server.  That seems to be the biggest difference in configuration, other
than CPU model.  I don't know that it could cause this problem, but it
would seem to be easy enough to test if they are not in production, yet.

Just grasping at staws here...

-- 
Scott Lambert                    KC5MLE                       Unix SysAdmin
lambert at lambertfam.org