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Conference ssag::ask_ssag

Title:Ask the Storage Architecture Group
Notice:Check out our web page at http://www-starch.shr.dec.com
Moderator:SSAG::TERZAN
Created:Wed Oct 15 1986
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:6756
Total number of notes:25276

6543.0. "help! identify performance difference" by HYDRA::LNARAYAN () Wed Apr 02 1997 16:49

A recent benchmark results show some strange behavior. 
This is a MF-COBOL application with unikix
(CICS for UNIX) a sequential read/write application.
We found the same application/program (with similar set of data)
that took 8 minutes on the the volumes 6,7 & 8, whereas it took 
23 minutes on the volumes 1,2,3.
This process is a part of the benchmark, which uncompresses and untar's 
8 files on eight volumes ( all are similar )  

The volumes are shown below.
My question is Why is the difference? can some one help me identify
this?

Thanks In Advance
Nari

Config:
S/W
Digital UNIX V4.0
LSM v4.0
MF COBOL 3.2A
swap 4 gb
console firmware revision 4.0

H/W
System       Alphaserver 8400 5/440
memory       4 GB

When I issue show config on the console, it lists me
on C0 four controller isp0 to isp3
and on C1 four controller kzpsa0 to kzpsa3. I dont know the
characteristics of these isp's, it came with the system as
default I guess.
the following is the SCSI device configuration

     |     isp0               BA350
     |-----------------------------------------------------
     |      |      |      |      |      |      |
 P   |    rz28  rz28m  rz28m   rz28   rz28   rz28
     |    rz1   rz2    rz3     rz4    rz5    rz6 
     |     isp1               BA356
     |-----------------------------------------------------
 C   |      |      |      |      |      |      |
     |    rz28   rz28   rz28   rz28   rz28   rz28
     |    rz9    rz10   zr11   rz12   rz13   rz14
     |     isp2               BA356
 I   |-----------------------------------------------------
     |      |      |      |      |      |      |
     |   st3255 st3255 st3255 st3255 st3255 st3255    ----> all are ST3255OW 
     |   rz17   rz18   rz19   rz20   rz21   rz22
     |     isp3               
 B   |------------------------------------------------------
     |      |
     |   rrd43
     |   rz29
 U   |            kzpsa0        BA350
     |------------------------------------------------------
     |      |      |      |      |      |      |
 S   |    rz28   rz28   rz28   rz28   rz28m  rz28
     |    rz33   rz34   rz35   rz36   rz37   rz38
     |            kzpsa1        BA350
     |------------------------------------------------------
     |      |      |      |      |      |      |
     |    rz28   rz28   rz28   rz28   rz28   rz28m 
     |    rz41   rz42   rz43   rz44   rz45   rz46
     |            kzpsa2        BA350
     |-----------------------------------------------------
     |      |      |      |      |      |      |
     |   rz28m  rz28m  rz28m  rz28m  rz28m  rz28m
     |   rz49   rz50   rz51   rz52   rz53   rz54
     |            kzpsa3        BA350
     |------------------------------------------------------
     |      |      |     
     |    tlz06  tlz06  
          



LSM mirrored volumes (one full disk is mirrored to another, the c partition)

    vol1    vol2     vol3     vol4     vol5     vol6     vol7     vol8
--------------------------------------------------------------------------
     |        |        |        |        |        |        |        |       
   rz2c     rz3c     rz4c     rz18c    rz19c    rz41c    rz42c    rz43c
   rz10c    rz11c    rz12c    rz34c    rz35c    rz49c    rz50c    rz51c ----->
                                                                        mirrors
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