Dell PV220S poor performance

I have PV-220S connected with Perc 3/DC to the PE 6450 server with 1GB RAM,
1xP3 700MHz CPU, running Win2k Adv. Server. PV is filled with 14 10krpm 73GB
harddisks and on the backplane there are three 18GB hdds. On both channels
there are RAID 5 logical disks. Performance of both logical disks are poor -
read about 5-6MB/s. I upgraded the PV220S firmware, perc firmware, windows
2000 perc driver and array manager, but perfoormance didn't grow. What's the
problem? What is the bottleneck in this system?

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Bartosz Konefal

"Konik" wrote:
I have PV-220S connected with Perc 3/DC to the PE 6450 server with 1GB
RAM,
1xP3 700MHz CPU, running Win2k Adv. Server. PV is filled with 14 10krpm
73GB
harddisks and on the backplane there are three 18GB hdds. On both channels
there are RAID 5 logical disks. Performance of both logical disks are
poor -
read about 5-6MB/s. I upgraded the PV220S firmware, perc firmware, windows
2000 perc driver and array manager, but perfoormance didn't grow. What's
the
problem? What is the bottleneck in this system?

I forgot about strip size: strip size is 64kB, I'm testing performance on
files with size about 1GB.

--
Bartosz Konefa³

Hello Bartosz,

I have PV-220S connected with Perc 3/DC to the PE 6450 server with 1GB
RAM,
1xP3 700MHz CPU, running Win2k Adv. Server. PV is filled with 14 10krpm
73GB
harddisks and on the backplane there are three 18GB hdds. On both channels
there are RAID 5 logical disks. Performance of both logical disks are

poor -
read about 5-6MB/s. I upgraded the PV220S firmware, perc firmware, windows
2000 perc driver and array manager, but perfoormance didn't grow. What's
the
problem? What is the bottleneck in this system?
I forgot about strip size: strip size is 64kB, I'm testing performance on
files with size about 1GB.
===

Have you tried to measure throughput for a single drive? (without any
RAID) You could try to run a benchmark like iozone to help you identify
the bottleneck if it ain't a production system. (...and turn on system
monitoring while you're running the benchmark)

BTW have you verified that you don't have a cable or termination
problem? Are you seeing a lot of kernel times, e.g. is the system
swapping while performing massive file transfers? How do you measure
throughput (cp, smb, rawrite ?)? Any scsi errors in the system log
during heavy activity?

Cheers,

Jochen

"Jochen Kaiser" wrote:

Have you tried to measure throughput for a single drive? (without any
RAID) You could try to run a benchmark like iozone to help you identify
the bottleneck if it ain't a production system. (...and turn on system
monitoring while you're running the benchmark)

It's impossible - this is a production server, main file server. I run tests
only by night or weekends, when users aren't connected.

BTW have you verified that you don't have a cable or termination
problem? Are you seeing a lot of kernel times, e.g. is the system
swapping while performing massive file transfers? How do you measure
throughput (cp, smb, rawrite ?)? Any scsi errors in the system log
during heavy activity?

There are no problems with cables - common problem is with internal
backplane of the server and external connection to PV220S.
System works normally, I've just reinstalled this server from Windows NT4.0
to Windows 2000 Server (new fresh installation) and problem didn't disapear.
I test performace using hdtach and copying big files (1GB) through network
(smb) or to another array of the same perc (backplane - channel 1).
Results are similar.
I think this is a question of some settings, not hardware failure. Do you
know what read speed should be on PV220S with Perc 3/DC?

--
Bartosz Konefal

Hi Bartosz,

There are no problems with cables - common problem is with internal
backplane of the server and external connection to PV220S.
System works normally, I've just reinstalled this server from Windows NT4.0
to Windows 2000 Server (new fresh installation) and problem didn't disapear.
I test performace using hdtach and copying big files (1GB) through network
(smb) or to another array of the same perc (backplane - channel 1).
Results are similar.
I think this is a question of some settings, not hardware failure. Do you
know what read speed should be on PV220S with Perc 3/DC?
===

http://lists.us.dell.com/pipermail/l...st/014766.html
and the thread under
http://lists.us.dell.com/pipermail/l...ly/014264.html
notes a performance of about 42MB/sec @ RAID5 (block write I assume)
under Linux, maybe you can email one of the authors for help. I've an
in-depth benchmark (bonnie++) for a Perc 3/DC with 3 to 5 attached
drives (although not a 220S) utilizing different raid techniques if
you're interested.

Cheers,

Jochen

Jochen Kaiser wrote:

I test performace using hdtach and copying big files (1GB) through
network (smb) or to another array of the same perc (backplane - channel
1). Results are similar.

A small comment..

Are you piping across a 100Mbit LAN pipe?
Then of o course all youre going to get is ~5-6MB/sec.

jk

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