Hi,
I have the following configuration:
Alphaserver 2100 wirh 512MB memory
7 x 1GB rz26l disks configured in a RAID with one hot standby disk. That
means I have 5GB usable space in the RAID. The RAID controller is a 3
port controller on the EISA bus.
1 x 2GB rz28 (System disk), 3 x 1GB (Swap) on a PCI SCSI controller.
I want to test the throughput on all these disks (raw and filesystem).
I used the following commands and received these results:
1.) RAW RAID:
time dd if=/dev/mem of=/dev/re0c bs=64k ---> 821K/s throughput
2.) RAW standalone disk:
time dd if=/dev/mem of=/dev/rz13c bs=64k ---> 578K/s throughput
3.) FIlesystem on RAID:
time dd if=/dev/mem of=/dev/raidfs/mem bs=64k ---> 2.7MB/s
throughput
4.) Filesystem on standalone disk:
time dd if=/dev/mem of=/dev/sfs/mem bs=64k ---> 1.9MB/s thoughput
Questions:
a) Why is the Filesystem tests better that the raw devices?
b) Shouldn't I get at least a throughput of 3MB/s on the raw devices?
c) Seeing that the PCI bus is a lot faster that EISA, why is the RAID
faster than the standalone disk?
d) Are the tests that I have performed valid at all? Is there another
more valid method to use?
Any replies will be appreciated!
Thanx.
Marius Booysen
Email: booysems_at_telkom09.telkom.co.za
Received on Fri Mar 03 1995 - 08:30:23 NZDT