Re: IO Bottleneck

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Thanks, I will try to collect some data with exmon.

One thing I've noticed is that my log files never grow above 5MB each...
35MB total... is that normal? Should I really use two 73GB disks to store
just 35MB?


"Simon Walsh" escribió:

Run an EXMON on the server.
Look for unusual user activity in real time.
Start with the worst offenders. Turn their Outlook client off. Any change?
What version of Outlook are they using? Have you installed all the latest
fixes for those clients?
Are their bunches of users that are sending/receiving the exact same amount
of bytes/second?
Just a few tips

/Simon.


"Ariel" <Ariel@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
news:0B83F4E4-B6EB-45AD-8AFF-DD46FEF3C47F@xxxxxxxxxxxxxxxx
My databases are 36GB in size.
I am not running blackberry.
Most of my clients use OWA.
I am not sure how to determine if the users have desktop search, I saw a
couple of ones, but it's probably 5 users in total.
I am not running indexing or message tracking.

PTA says that user activity is unusually high.

Thanks for all your help

"jamestechman@xxxxxxxxx" escribió:

You're absolutely correct, this server should be able to support
substantially more than 300 users. Let's try to get some more info as
to the source of your I\O bottleneck in terms of user IOPS. How big are
your user's MB? Are you running Blackberry? Are your clients running
any desktop search engines, ie. google desktop search, yahoo desktop
search... Are you doing any Exchange indexing? What other applications
are running on the server?

James Chong
MCSE M+, S+, MCTS, Security+
msexchangetips.blogspot.com


Ariel wrote:
Bummer, I really don't know what I'm gonna do now... probably change
the
delay for the RPC dialog so I don't get so many complaints, until I am
able
to buy a new server. What really bothers me is that this server,
properly
configured, should be able to service much more than 300 users...

"John Fullbright [MVP]" wrote:

Write cache could remorve 1 IO operation out of 4 for RAID 5.
Instead of
defining write performance as P*N'/4, you could descibe it as P*N'/3.

For your 4 drive RAID 5 array using 10K drives, your current write
performance would be something like 85*3/4 or 61 IOPS. Adding the
write
cache could, depending on controller architecture, change that to
85*3/3 or
85 IOPS. I doubt that, in practical terms, it would make much
difference.



"Ariel" <Ariel@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
news:C812D79F-A273-4DA4-908A-79514F8E5096@xxxxxxxxxxxxxxxx
John:

Thanks for your response. The way you describe is exactly how I
would
design
a new server. However, this is our only exchange production server,
and I
need to improve performance as much as possible without
reinstalling it.

So, would adding the battery backed write cache improve performance
in a
significant way? And would I be better of moving something else to
the
logs
disk, say, the smtp queue or temp dirs?

"John Fullbright [MVP]" escribió:

At a minimum, you should have a mirror for the OS, a mirror for
the logs,
and a mirror (or RAID 10) for the databases. I'd hazard a guess
that the
write times on the the RAID 5 array far exceed 20ms.


"Ariel" <Ariel@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
news:F0839239-546B-4AA9-8B55-5B0E7A4DC986@xxxxxxxxxxxxxxxx
I have recently become the administrator of an Exchange 2003
Server.
These
are the server specs:

HP Proliant DL380 G3
Dual Xeon 2.8GHz
2GB RAM
Smart Array 5i Controller with 64MB and read-only cache
4 x 300GB Ultra320 10K Hard Drives in a RAID 5 array

I have been assigned the task to investigate a possible
bottleneck,
since
users were seeing the RPC dialog frecuently. I ran the
Performance
Troubleshooting Analyzer, and of course, the results indicated a
disk
bottleneck.

The server has room for 2 more hard drives. I tried adding a
73GB disk,
and
using it for the database logs, then ran the PTA again, and now
the
report
says that I have a disk bottleneck in all the roles that
remained on
the
primary array.

I am going to add another 73GB disk to make a RAID 1 array, and
move
the
logs anyways, but I was wondering if I should transfer another
role to
that
new volume.
I am also considering buying an upgrade for the controller to
add 128MB
of
battery-backed write cache, if it would help.

I would appreciate any advice you have to offer.

Regards,

Ariel.











.

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