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Home > Archive > Data Storage > August 2004 > How to improve Escalade SATA RAID speed
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How to improve Escalade SATA RAID speed
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| Bob Brokman 2004-08-04, 2:45 am |
| Hi,
I am comparing SATA single drive performance with the SATA RAID 5
and RAID 0 performance (the RAID is built of 4 drives) and getting
counter-intuitive results.
Initially, my test was to copy 100 files 12MB each in size under Redhat 9
linux. When I copied from the disk to /dev/null (effectively just reading
the
files) it took 23 seconds for the single drive and 32 seconds for the RAID
5.
RAID 0 gave me similar numbers. When I copied from one file to another on
the same drive it took 68 seconds for the single drive and 93 seconds for
the RAID 5. Again, RAID 0 gave me similar numbers. I would expect
the RAID to be faster, especially the RAID 0 for the read operations.
Then I found some articles and tried to repeat what other people did using
benchmark tools. I used iometer under both Redhat 9 linux and
Windows 2000 OS, and obtained speed of 54 MB/sec. for both of them
when running against RAID 0 configuration of 4 drives. This is in-line with
my initial copy-file experiments, but is way too slow compared to speeds
reported by others. I have used 64 KB size requests and 100% sequential
reading.
My system is running Linux 9 with EXT3 filesystem and Windows 20000
with NTFS filesystem. I am using Intel SE7501CW2 motherboard with 1GB
of RAM and 3Ware 9500S-4LP SATA controller with the latest 3Ware
firmware (2.02.00.011) and drivers (9.0.1). I have 4 Seagate ST3120026AS
drives attached to the controller and I tried both RAID 5 and RAID 0
configurations.
Any ideas or similar experiences? May be there are some well-hidden
settings I could tweak to reach the optimal performance?
Thanks,
Bob.
===== Configuration details from 3ware 3DM web admin tool =======
== Controller Summary:
ID : 0
Model: 9500S-4LP
Serial #: F18402A4210121
Firmware: FE9X 2.02.00.011
Driver: 2.4.1.38
Status: OK
== Unit Information (Controller ID 0):
Unit #: 0
Type: RAID 0
Capacity: 446.99 GB
Status: OK
== Drive Information (Controller ID 0):
Port #: (0, 1, 2, 3)
Model: (ST3120026AS, ST3120026AS, ST3120026AS, ST3120026AS)
Capacity: (111.79 GB, 111.79 GB, 111.79 GB, 111.79 GB)
Serial #: (3JT4K7QD, 3JT19NMX, 3JT45656, 3JT4532Q)
Firmware: (3.18, 3.18, 3.18, 3.18)
Unit: (0, 0, 0, 0)
Status: (OK, OK, OK, OK)
== Controller Settings
Background Task Rate (Controller ID 0)
Rebuild Rate: 80% Faster I/O
Verify Rate: 80% Faster I/O
Unit Write Cache (Controller ID 0)
Unit 0 [RAID 0]: Enabled
Unit Policies (Controller ID 0)
for Unit 0 [RAID 0]:
Auto Verify: NO
Continue on Source Error during Rebuild: --
Other Controller Settings (Controller ID 0) [change through BIOS]
Number of Drives per Spin-up: 1
Delay between Spin-up: 2 second(s)
Export Unconfigured Disk: No
Disable Write Cache on Unit Degrade: No
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| Steve Cousins 2004-08-05, 5:45 pm |
| Bob Brokman wrote:
> My system is running Linux 9 with EXT3 filesystem and Windows 20000
> with NTFS filesystem. I am using Intel SE7501CW2 motherboard with 1GB
> of RAM and 3Ware 9500S-4LP SATA controller with the latest 3Ware
> firmware (2.02.00.011) and drivers (9.0.1). I have 4 Seagate ST3120026AS
> drives attached to the controller and I tried both RAID 5 and RAID 0
> configurations.
You might try using xfs instead of ext3. I have a 3Ware 8506 controller that
showed a 10-20% increase in throughput when I switched to XFS using RAID 5 with
9 250GB drives. Try some different values of sunit and swidth. I used
bonnie++ to test throughput.
Good luck,
Steve
________________________________________
______________________________
Steve Cousins, Ocean Modeling Group Email: cousins@umit.maine.edu
Marine Sciences, 208 Libby Hall http://rocky.umeoce.maine.edu
Univ. of Maine, Orono, ME 04469 Phone: (207) 581-4302
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| Priit Poldmaa 2004-08-05, 5:45 pm |
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"Bob Brokman" <beboris@earthlink.net> wrote in message news:9K0Qc.8779$9Y6.5979@newsread1.news.pas.earthlink.net...
> Hi,
>
> Any ideas or similar experiences? May be there are some well-hidden
> settings I could tweak to reach the optimal performance?
>
Have you read the performance tips fro 3ware's Knowledge Base?
http://www.3ware.com/KB/kb.asp
Q10036 for example did help me a lot.
Regards
Priit
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