Michael Worobcuk wrote:
Hi,
I am trying to set up my first webserver. I bought a Dell Poweredge 860, provided with a SAS5/IR RAID-Controller. The problem is now, that I cannot find software, that monitors the state of my disks. I already tried megarc from the ports but all I get is a short answer that no adapters where found:

#########################################################################
megarc -AllAdpInfo -nolog


********************************************************************** MEGARC MegaRAID Configuration Utility(FreeBSD)-1.04(03-02-2005)
              By LSI Logic Corp.,USA
**********************************************************************
          [Note: For SATA-2, 4 and 6 channel controllers, please specify
Ch=0 Id=0..15 for specifying physical drive(Ch=channel, Id=Target)]

        Type ? as command line arg for help

        No Adapters Found

        Error: No MegaRaid Found
#########################################################################

I had emails with Dell and LSI. Dell does not support FreeBSD and LSI says I should go and ask Dell ...


The second thing is, the perfomance.

<<<<SNIP>>>>

Final score for writes:            16
Final score for reads :          2025
 #########################################################################

(Just to remember: Pentium D; 2,8GHZ; 4 GB RAM; 2 x 500GB SATA RAID1)
That is pretty poor, isn't it ?


I am wondering now, if somebody has experience with the PERC5/I Controller. Would it be possible to monitor the disks, if I would buy that controller ?
Any hints are highly appreciated.

Thanks

Michael


I don't know about monitoring the SAS5/I however I read some posts on one of the lists that was talking about the linux compatibility system providing all of the correct interface for the linux version of ?megacli? to work on FreeBSD. As the SAS5/I is mpt driver based could it not be checked with camcontrol? (Just an idea never tested).

As for performance issues with the SAS5/i, there is a problem in the controller. A work arround was created by Scott Long which created a sysctl that could be set to cause the controller to turn on the on drive write cache's. These changes where commited to RELENG_6 on 2007-06-05 21:32:57 UTC.

The PERC5/[ei] controllers do not suffer the performance problems of the SAS5/i controller, we have ~30 systems with these controllers and have never seen any performance problems with them even when they have 20 drives attached to them.

If you had search the archives you would have found an almost identical response by me to an almost identical question regarding the SAS5/i performance problem.

Tom


Here is the original commit log:

scottl      2007-06-03 23:13:05 UTC

  FreeBSD src repository

  Modified files:
    sys/dev/mpt          mpt.c mpt.h mpt_cam.c
  Log:
  mpt.c:
  mpt.h:
          Add support for reading extended configuration pages.
  mpt_cam.c:
Do a top level topology scan on the SAS controller. If any SATA device are discovered in this scan, send a passthrough FIS to set the write cache. This is controllable through the following tunable at boot:

          hw.mpt.enable_sata_wc:
                  -1 = Do not configure, use the controller default
                   0 = Disable the write cache
                   1 = Enable the write cache

          The default is -1.  This tunable is just a hack and may be
          deprecated in the future.

Turning on the write cache alleviates the write performance problems with SATA that many people have observed. It is not recommend for those who value data reliability! I cannot stress this strongly enough. However, it is useful in certain circumstances, and it brings the performence in line with what a generic SATA controller running under the FreeBSD ATA driver provides (and the ATA driver has had the WC enabled by default for years).
_______________________________________________
freebsd-stable@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-stable
To unsubscribe, send any mail to "[EMAIL PROTECTED]"

Reply via email to