On Mon, 19 Jul 2004 15:59:35 +0200, "Benno..." <0@0.invalid> wrote:

>
>I setup a test server to do some performance tests. I collected a
>dataset of 26 profiles (216MB in 46.075 files and 1773 directories).
>Copying them from the server to a workstation gives an average speed of
>420KByte/sec (the test server is newer and has therefor better
>performing disks/arraycontroller then the production server in my
>previous post. The production server gets around 230KB/sec on the test
>dataset).
>If I copy this dataset on the server itself from the RAID1 boot/system
>partition to the RAID5 data partition I see 2500KByte/sec.

Are you doing these tests single-stream (i.e., only one process doing the
transfers)?

Realize that your real-world workload would be multiple users accessing
their profiles simultaneously, through separate processes.  This is quite a
different workload than a test that only has one process transferring the
data sequentially.

Note, too, that in order to determine where the bottleneck is, you'd have
to study more than the server disk subsystem - desktop memory & CPU,
desktop disk drive & controller, NIC, network switch the desktop is
connected to, back bone network in-between server & desktop, server NIC,
server memory & CPU,. I/O controller, disk subsystem.

In any multi-user system (user is a loose term to describe multiple,
simultaneous processes accessing disk drives), the more spindles you have
the better, in general.  This can reduce management headaches of
performance issues on "hot-spot" drives, while you have other drives
relatively I/O free.  Putting them into larger sets of spindles allows your
workload to balance (statistically) among the available spindles and
reduces contention for individual spindles.

In any case, though, your transfer time across the network is generally
going to be more dependent on the network link than the storage I/O link.

--- jls
The preceding message was personal opinion only.
I do not speak in any authorized capacity for anyone,
and certainly not my employer.
(get rid of the xxxz in my address to e-mail)

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