Hello linux-raid!
I'm a newbie, so please forgive any stupidity. I've searched and read
diligently and feel I need to ask this more specifically. I have:
Dell 6300
Dual 400 mHz Xeon w/512K cache each
1GB RAM
Adaptec SCSI controller
Dell PERC 16MB (AMI MegaRAID)
Redhat 6.0 vanilla (2.2.5-15)
6-18GB Quantum 7200 RPM in
RAID 5
I've been benchmarking Oracle on this server against an identical
Oracle instance on an IDENTICALLY EQUIPPED NT server. The Linux box
KICKS the NT's butt, drastically, on all but the simplest, least
loaded queries. I've got statistics if anyone is interested.
Given the Linux box is so much faster than the NT server, and given
I'm using a (reputedly) slow RAID controller, I'd like to verify
something before proceeding. IF this RAID controller is so slow,
I can imagine the performance margin would increase if I could
increase the RAID performance.
All the reading I've been doing would suggest that the MagaRAID
controller is the slowest RAID solution I could choose. Based on
the Bonnie stats below, I THINK I recognize what is meant. The
final two Bonnie runs on files of size 2047GB look like the IO is
a serious bottleneck.
But I need help and validation to continue.
1) Am I correct in reading the Bonnie numbers to say the greatest
throughput (using a file of size 2047GB) is 9.655MB during the
Sequential Block Input, and does that mean "write" or "read"?
2) Regarding the hdparm output, is it saying the best disk read
is 12.08 MB/sec?
3) And does this reinforce the Bonnie stats?
4) Isn't this all pretty slow?
5) if so, is there anything I can do about it?
-- ===================================================================== --
-- I ran Bonnie against the described server: --
--------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
128 4793 77.7 62438 100.0 12211 41.8 6177 98.3 174710 100.0 8344.5 200.3
128 6112 99.0 62926 99.4 31905 96.9 6205 98.3 154055 97.6 8362.8 200.7
256 4097 66.1 30336 47.0 18749 68.2 6197 98.5 161505 99.8 7746.3 199.5
256 6081 99.3 36635 55.8 16771 57.4 6185 97.9 161112 100.8 7698.8 190.5
512 3983 65.4 13016 21.7 7956 36.8 6214 99.0 140129 100.2 2839.2 75.9
512 6026 97.9 12731 22.2 7931 32.6 6239 99.0 140255 100.1 2821.9 75.5
1024 4796 77.8 8991 17.2 4615 18.5 5103 80.6 10319 19.0 408.7 10.4
1024 5646 92.4 9094 17.9 5081 21.5 4911 77.5 8887 18.2 396.5 9.5
2047 4630 75.7 8577 18.6 4559 18.0 5274 82.6 9655 20.1 98.7 3.9
-- ===================================================================== --
-- I ran hdparm and got these results: --
[root@patty system_stats]# hdparm -tT /dev/sda5 /dev/sda6
/dev/sda5:
Timing buffer-cache reads: 64 MB in 0.62 seconds =103.23 MB/sec
Timing buffered disk reads: 32 MB in 2.65 seconds = 12.08 MB/sec
/dev/sda6:
Timing buffer-cache reads: 64 MB in 0.64 seconds =100.00 MB/sec
Timing buffered disk reads: 32 MB in 2.69 seconds = 11.90 MB/sec
-- ===================================================================== --
Any and all input will be greatly appreciated. You may respond directly if you
don't want to bother the rest of the list with this (probably) infantile question.
Best regards,
Kevin
=========================================
Kevin Soukup
phone: (815) 235-6944 (wk)
phone: (815) 232-4133 (hm)
FAX: (815) 235-5959 (wk)
e-mail: [EMAIL PROTECTED]
=========================================
