Date: Tue, 2 Mar 1999 15:20:28 -0500 (EST)
From: David Mansfield <[EMAIL PROTECTED]>
I am concerned that these stats for bonnie are in fact pretty poor for the
hardware involved. Could someone running SW RAID5 on similar hardware
comment on your bonnie findings?
I have a DAC960:
DAC960: ** DAC960 RAID Driver Version 2.2.0 Beta4 of 13 January 1999 **
DAC960: Copyright 1998-1999 by Leonard N. Zubkoff <[EMAIL PROTECTED]>
DAC960#0: Configuring Mylex DAC960PG PCI RAID Controller DAC960#0:
Firmware Version: 4.06-0-00, Channels: 2, Memory Size: 8MB DAC960#0: PCI
Bus: 0, Device: 16, Function: 1, I/O Address: Unassigned DAC960#0: PCI
Address: 0xFD4FE000 mapped at 0xD0800000, IRQ Channel: 11 DAC960#0:
Controller Queue Depth: 64, Maximum Blocks per Command: 128 DAC960#0:
Driver Queue Depth: 63, Maximum Scatter/Gather Segments: 33
DAC960#0: Stripe Size: 64KB, Segment Size: 8KB, BIOS Geometry: 128/32
with 6 UW Quantum Viking II 4.5GB drives, three on each channel,
configured (by VA Research) into a Raid5 volume. The system is a dual PII
450Mhz, running linux kernel 2.2.2 (a RedHat 5.1 + upgrades system), with
256MB ram. Note, the bonnie file size is 500MB (about double phys. ram).
Here is the bonnie output (slightly edited to fit well in 74 columns):
File './Bonnie.4392', size: 524288000
Writing with putc()...done
Rewriting...done
Writing intelligently...done
Reading with getc()...done
Reading intelligently...done
Seeker 1...Seeker 2...Seeker 3...start 'em...done...done...done...
-------Sequential Output-------- ---Sequential Input-- --Random--
-Per Char- --Block--- -Rewrite-- -Per Char- --Block--- --Seeks---
MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec %CPU
500 3742 46.8 4623 6.7 2604 7.9 6614 72.9 13314 14.6 183.4 3.2
vmstat shows blocks in and out maxing out at 9000, but typically in th
4500-5500 range at any given time.
If these are in fact poor numbers, what is wrong with my system. I feel
like I should be seeing numbers 5 times these.
I expect that the performance issue is that the logical drive is configured for
Write Thru caching for safety reasons. If you use the BIOS Configuration
Utility to enable Write Back caching, I expect the numbers will increase
dramatically. In order to use Write Back caching safely, one really should
have a battery backup unit installed or at least a UPS. Please give that a try
and report on the results you achieve.
Leonard
