I've recently installed a MD3000 with a red hat 5.3 host on a SAS 5/e and am experiencing similar performance figures also using various raid types and file systems.

Did you manage to improve on this?

Apologies, as I can't seem to get the report's columns to align here

We are running an MD3000 with dual SAS controllers (non-redundant with 3 hosts connected to non-shared Luns). It is chained to an MD1000. Both are populated with 1TB SATA (7200) drives. Running IOMETER  on our Windows 2003 x64 servers we've seen:

6+1 Raid5 w/256K Segments  (non-aligned partition blocked at 4k) :

            Single stream (64k nonbuffered) sequential writes = approx 80MB/sec,  6 streams = approx 115MB/sec

7+1 Raid5 w/64k Segments (aligned partition blocked at 64k) :

            Single stream (64k nonbuffered) sequential writes = approx 40MB/sec,  6 streams = approx 300MB/sec (some tests higher)

We are somewhat baffled at the disparity between the single stream tests .... We would have thought that the aligned w/larger (Windows) blocksize would yield better results --- even on a single stream (It certainly does on multiple streams). The 6+1 Raid is entirely on the MD3000, while our 7+1 Raids all have at least 1 drive on the MD1000 extension. We were wondering if there might be a troublesome disk (disks?) on the MD1000, but everything appears Optimal. However, we ran a System State report via the CLI interface and are seeing a LARGE number of (Unit ATTN) I/O errors attributed to the (MD1000) enclosure itself :

Client: 02.71.G6.07 built at Wed Mar 12 11:13:22 CST 2008

   Current configuration
      Firmware version:      06.70.15.60
         Appware version:    06.70.15.60
         Bootware version:   06.70.15.60
      NVSRAM version:     N133X-670890-001

chAll (Tick 0111881069) ==> 06/03/09-13:53:57 (GMT) 1332-A 06.70.15.60

.....Channels.....:...........Target...........:............Initiator.......... Link :ITN :..........IOs..........:ITN :............IOs...........

Ch H/D STP Down :cnt : Open Completed Errs :cnt : Qd Open Completed Errs

---- --- --- ---- :--- :----- ---------- ----- :--- :--- ----- ---------- -----

0 Drv SAS 0 : 1 : 0 178377 4 : 32 : 0 0 619156885 177302

1 Drv SAS 0 : 1 : 0 177580 2 : 32 : 0 0 132593985 176525

2 Hst SAS 0 : 1 : 1 637747373 53 : 0 : 0 0 0 0

-< 3 Hst SAS 0 : 0 : 0 0 0 : 0 : 0 0 0 0

-> luall 1

Initiator IO Breakdown
....Logical Unit....     :.....Open IOs.....         :..........R E A D S.........              :........W R I T E S.........        :..NON R/W...      :..WRT/VFY..
    Devnum Location : Read Write NonRW    :  #Success BlksXfered #Errs      :  #Success BlksXfered #Errs :#Succ #Errs        :#Succ #Errs

 00000010  t1           :      0      0           0     :              0               0      0       :              0                 0     0  :774541 388464   :    0     0

-> luall 0
.......Logical Unit........:    :annel:Que ............IOs...........
    Devnum Location Role   :ORP : 0 1 :Dep  Qd  Open  Completed  Errs
---------- -------- ------ :--- : - - :--- --- ----- ---------- -----
00000010  t1        Encl :++  : A B :  1   0     0    1058590 353635

-> iditnall 0
...IDITN..:.......Logical Unit........:Port :............IOs...........
 iditn Ch :    Devnum Location Role   :Byte : Qd  Open  Completed  Errs
------ -- :---------- -------- ------ :---- :--- ----- ---------- -----
    32  0 :  00000010  t1        Encl :0x00 :  0     0     529526 177115
    34  1 :  00000010  t1        Encl :0x00 :  0     0     529064 176520

Initiator IO Errors
                     :     :........................................E R R O R S..............................
                     :Chan    :.....Driver....             :........SCSI Check Conditions...........                     :......SCSI Status.......
.Channel     :....IOs....:Rlat : HID  LID           :Rec-  Not                      Ill    Unit  Abrt                  :     Resv    Q  ACA    
  Ch H/D : Completed :Errs :Abrt Dtec  EDC :ovrd Redy  Med  H/W  Req   Attn  Cmd Othr          :Busy Conf Full Actv Abrt
   ----  --- :        ---------- : ---- :  ---- ----- ---        : ----   -----   ----      ----    ---     ----       ---- ----            :----   ----   ----   ---- ----
     0 Drv : 619156885 :    2 :    0    2     0      :   0       0    0         0   144 175875    0    0             :   1    0 1280    0    0
     1 Drv : 132593985 :    0 :    0    0     0       :  0       0    0         0      1  176324    0    0             :   1    0  199    0    0

There is much more to the report that I won't post due to its size. We're about to open an incident with Dell, and are wondering if anyone else is seeing numbers like this?

Are you sure all these FW's are up to date,  check the EMM's on the 1000 expansion chasis as well?

We use MD3000i's and I was not really able to extrapolate to much to your running setup here.

We span stuff all over the MD3000i's with MD1000's attached.  So no specific issues with that as far as I know.  We have found if things get flakey?  It is not a bad idea to reset the power supplies and in our case the controllers in these chasis.  They get a little loose over time, moving them around, ect..ect...