clusters

[bob]

I have a programmer on my staff who is giving me difficulties.

we have a database server (progress), win2000 sp4, quad processor, 4gb ram,
raid 0+1 (3 drives stripe set, mirrored) with 4k default cluster size.

this server's disk I/O performance is abysmal.

First, the guy argues that there's any value to defragging (he think's there
is none).

second, i mentioned since we are using a db application that supports 8k or
greater cluster sizes, that we should consider increasing the cluster size
on the volume.

so here's my delimma. I need to find an article to PROVE to him that larger
cluster sizes CAN have a performance increase in situations like this.

does any one have any links on articles about cluster size and performance?

i tried googling, and all i can come up with is just generic or non specific
info. In other words, they say that increasing cluster size COULD increase
performance for large file size (multimedia, database). but none of them
actually PROVE it.

i need to find a doc that i can show him to stuff up his littlee...uh...you
get the picture.

anyways, i suggested we take and do an in house performance test: setup a
test server, 4k clusters, benchmark. set to 8/16k cluster size, benchmark,
compare. he thinks it is a waste of time (mainly because it might prove that
I know what i'm talking about).

anyways, i've since learned that this guy won't take my word for it no
matter what I say. so i have to find a documented expert source to prove it.

i searched MS's kb. couldn't find anything.

i'm so desperate to prove to this guy that my suggestion to increase cluster
size could help us with Disk i/o. (i've done enough perfmonning to
demonstrate clearly it's not processor, memory, network. it's disk).

we've got a 7gb database that can be set to 8/16k cluster sizess. i
suggested we set the file system volume to 16/32/64, set the db
approproately and give it a real world test.

he's not interested.

so....i have to find a reputable whitepaper / source that clearly shows
larger cluster size in a db / ntfs file environment could help improve
cluster size.

if i'm wrong, then i've learned something. it seems to me that if a db has
to read several pages of data 4k at a time, rather than 64k at a time, that
we are not being efficient. it seems to me that if we could utilize larger
clusters, it'd be a potential boost to disk performance.

help me either 1) prove i'm wrong, or 2) help me get him to see the light. I
hate situations like this. but i guess it's real world. they don't want to
take my word for it. fine.

HELP! I'm an IT Pro in distress who's being told he doesn't have a clue!
help me find the clue!

 

[Galen]

In

I have a programmer on my staff who is giving me difficulties.

I'll address this first. It's your staff, I think if I'd a programmer on my
staff who wasn't listening to me at least to hear what I had to say I'd find
a new coder. That being said this is an older article based on NT but has
some good information about cluster size. What you also need to know is the
average size of the files that will be stored but you can read more on your
own if you'd like:

http://www.windowsitpro.com/Windows/Article/ArticleID/4875/4875.html

I'd consider them a reputable source but, again, a key issue in this case
definitely is knowing what the average size of the files is going to be and
then partitioning with the correct cluster size before trying any
benchmarks. Getting the information from a single cluster would be more
efficient but clusters larger than they need to be are going to waste space.
Unless, of course, I'm missing something here but it sounds right to me

Galen
--

"My mind rebels at stagnation. Give me problems, give me work, give me
the most abstruse cryptogram or the most intricate analysis, and I am
in my own proper atmosphere. I can dispense then with artificial
stimulants. But I abhor the dull routine of existence. I crave for
mental exaltation." -- Sherlock Holmes