On Sat, Jan 1, 2011 at 5:28 PM, John Mellor <john.mellor(a)gmail.com> wrote:
On Sat, 2011-01-01 at 16:43 -0800, suvayu ali wrote:
> On Sat, Jan 1, 2011 at 3:23 PM, John Mellor <john.mellor(a)gmail.com> wrote:
> > I've got a 1.5TB Western Digital Green drive, and I'm not happy with
the
> > performance of it. There are also several discussions online about
> > these drives having an early ageing problem with ext4 filesystems
> > because of them unloading the heads every 5 seconds and ext4 only
> > flushing its journal every 30 seconds.
> >
>
> I have 2 1TB WD Black drives and one 300GB Velociraptor they all have
> been working almost flawlessly. Could you please point me to what kind
> of symptoms I might see if the above was true for my case?
>
> PS: Did you by any chance get the unloading of heads and ext4 flushing
> its journals interchanged? If not, I don't see how that would be a
> problem.
No, the problem is that with 30-second journal flushes to a WD green
drive that unloads every 5 seconds, every time Linux goes to write to
the disk, the heads have already been unloaded. Loading them again
takes a relatively long time, killing the performance. Also, if you
look up the green drive specs, they are only good for about 100k
load/unload operations, or a lot less than 2 months unless you do
something about it.
Thanks John for the explanation and the confirmation that I'm safe. :)
--
Suvayu
Open source is the future. It sets us free.