[K12OSN] new server serial ATA or SCSI - results on new 3ware card

[Chris Kacoroski]

Hi,

I got my new system with the following specs:
- 3ware controller #1 with (2) sata drives in mirrored config as system 
disk
- 3ware controller #2 with (9) sata drives in raid 5 split into 2 912GB 
partitions (sdb1 & sdb2)
- Redhat AS3 with all the patches (2.4.21-9.0.1.ELsmp kernel)
- Dual Xeon 2.4Ghz cpus with hyperthreading so they look like four 
processors

and the results I get with hdparm -tT when run individually are:

/dev/sdb2:
  Timing buffer-cache reads: 2440 MB in 2.00 seconds = 1220 MB/sec
  Timing buffered disk reads: 132 MB in 3.01 seconds = 43.85 MB/sec

/dev/sdb1:
  Timing buffer-cache reads: 2436 MB in 2.00 seconds = 1218 MB/sec
  Timing buffered disk reads: 132 MB in 3.03 seconds = 43.56 MB/sec

/dev/vg00/lvRoot:
  Timing buffer-cache reads: 2228 MB in 2.00 seconds = 1214 MB/sec
  Timing buffered disk reads: 110 MB in 3.03 seconds = 36.30 MB/sec

when I run them at the same time, the results drop to:

/dev/sdb2:
  Timing buffer-cache reads: 1760 MB in 2.00 seconds = 880 MB/sec
  Timing buffered disk reads: 102 MB in 3.14 seconds = 31.19 MB/sec

/dev/sdb1:
  Timing buffer-cache reads: 1780 MB in 2.00 seconds = 890 MB/sec
  Timing buffered disk reads: 98 MB in 3.03 seconds = 32.34 MB/sec

/dev/vg00/lvRoot:
  Timing buffer-cache reads: 1200 MB in 2.00 seconds = 600 MB/sec
  Timing buffered disk reads: 108 MB in 3.00 seconds = 36.00 MB/sec

To me the interesting thing is that the system partition also slows 
down even though it is on a separate 3ware card.  I plan to do some 
more extensive testing next week, but initially it looks like it will 
keep up with a scsi based system.


--
"When we try to pick out anything by itself, we find it
   connected to the entire universe"		John Muir

Chris "Ski" Kacoroski, ckacoroski at nsd.org, 425-489-6263

On Feb 25, 2004, at 6:48 PM, Sudev Barar wrote: