Your 'fastest' figures below are very interesting to me. You are getting
200+ K/sec random IO speeds with only 6 drives whereas I am getting
around 150K/sec random I/O w/ 9 drives. Your ST32155W's are 5400RPM
drives with slower internal transfer rates and latency than my ST15150W's.
Even though you are using RAID 0 opposed to my RAID 5 I would have assumed
that the Random I/O figures as reported by Bonnie to be comparable.
Plus you are using one controller for all six of your drives whereas I
have three controllers with three drives each. I wonder if there is not
another configuration issue here that is slowing down my system. Anyone
else getting >150K/sec w/ bonnie for RAID 5?
Steve
-----Original Message-----
From: Kim-Ee Yeoh <[EMAIL PROTECTED]>
To: Stephen Costaras <[EMAIL PROTECTED]>
Cc: [EMAIL PROTECTED] <[EMAIL PROTECTED]>
Date: Tuesday, November 10, 1998 7:21 AM
Subject: Re: Improving RAID5 performance (what disks/configuration?)
>On Sat, 7 Nov 1998, Stephen Costaras wrote:
>> I'm using a Dual PPro system (Tyan S1668) with 3 Mylex KT-958
>> controllers. Each controller has 3 Seagate Barracuda ST15150W
>> drives (fast/wide, approx. 5MB/sec internal transfer bandwidth).
>> I have all nine disks in a RAID 5 array, so I figure 15*3=45MB/sec
>> usable bandwidth. Raidtab has everything configured for 64k chunks.
>> SNIP
>> (system has 256MB memory, CPU utilization is around 50-60% of one CPU,
>> kernel=
>> 2.0.35)
>> -------Sequential Output-------- ---Sequential
Input-- --Random--
>> -Per Char- --Block--- -Rewrite-- -Per
Char- --Block--- --Seeks---
>> Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec
%CPU
>> news:md0 1000 6213 89.0 11416 50.6 4412 34.4 6813 73.3 8395 23.8
149.7 10.0
>
>Here's are some more (RAID0 _not_ 5) numbers for comparison. Mine is
>a dual 233MHz ppro (Intel Providence PR440FX), 128MB RAM, with a single
>Mylex 958 on which are RAIDed 6 Seagate Hawk ST32155W (2GB) disks. Note
>that these disks belong to a previous generation -- Seagate no longer
>sells them.
>
>Kernel is 2.1.125 with 19981106-C-2.1.125 patches. Slowest and fastest
>configurations are given below.
>***************** RAID0: 32KB chunk, 4KB ext2 block, stride=8
>[root@iam /zu]# bonnie -s 512 -m "raid0,32k,4k,8" -d /zg
>File '/zg/Bonnie.3780', size: 536870912
> -------Sequential Output-------- ---Sequential
Input-- --Random--
> -Per Char- --Block--- -Rewrite-- -Per
Char- --Block--- --Seeks---
>Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec
%CPU
>raid0,32 512 3684 99.3 24511 65.4 9543 58.0 4569 94.2 22334 51.1 214.1
5.9
