Oracle FAQ Your Portal to the Oracle Knowledge Grid

Home -> Community -> Usenet -> c.d.o.server -> Re: .dbf files on external USB disk - doable?

Re: .dbf files on external USB disk - doable?

From: Dusan Bolek <>
Date: 3 Jun 2004 00:38:59 -0700
Message-ID: <>

"Howard J. Rogers" <> wrote in message news:<40be6e01$0$31680$>...
> > My Oracle database needs more disk space than I have available on my
> > work station, and I am considering hooking up an external disk with a
> > USB interface, and moving all Oracle data files there.
> It can be done. But I wouldn't do it. It would be far better to upgrade the
> hard disk inside your workstation.
> That is, if this is in any serious sense a database. I know you say you
> don't particularly care about performance, but that's only one of the
> issues. Performance will be poor, even at USB2.0 speeds. But the real worry
> is what happens when your USB cable gets pulled out, or the power supply to
> the external device is accidentally removed. I know Oracle has recovery
> mechanisms, but unless you're planning on testing them to their limits, I
> wouldn't risk it.

The advice from HJR is sound. However, if you really need an external drive think at least about different interface. I do not know what kind of workstation do you have, but many of the new ones are equipped with a fireware interface. It is much better than USB 2.0, because not only it is quicker, but also gives a much more predictable speed results.
The maximum speed of USB 2.0 drive is almost as good as with the firewire, but variance of results can be enormous. Before some time, I tested an USB 2.0 external drive and it sometimes slowed down to about 25% of maximal achieved throughput! It seems to me that performance USB is quite sensitive to the overall machine load. You can easily imagine what this means when you deploy your even testing database on it.

Dusan Bolek

Pls add "Not Guilty" to the subject, otherwise your email will face an
unpleasant end as SPAM.
Received on Thu Jun 03 2004 - 02:38:59 CDT

Original text of this message