[Beowulf] Big storage

[Jakob Oestergaard]

On Thu, Aug 30, 2007 at 09:53:04AM +0200, Leif Nixon wrote:
> Jakob Oestergaard <jakob at unthought.net> writes:
> 
> > I'm looking at getting some big storage. Of all the parameters, getting as low
> > dollars/(month*GB) is by far the most important. The price of acquiring and
> > maintaining the storage solution is the number one concern.
> 
> Even at the price of reliability.

Yes, to some extent.

...
> They are nice, I understand. And seem like a good approach. The
> vendors will likely want to sell you SAN-ified systems with cluster
> file systems and lots of Windows-only management software. It can take
> some convincing to get them to understand that that is actually not
> what you are looking for.

Yup :)

...
> > Any better ideas? Is there a way to get this more dense without
> > paying an arm and a leg? Has anyone tried something like this with
> > HSM?
> 
> That is probably not worth the bother.

I find it interesting (and surprising) how little people like tape :)

> But something that you have to be prepared for when going to that
> storage volume is that you *will* suffer data corruption at some
> point, and you need to plan for it. See for example
> 
>   http://cern.ch/Peter.Kelemen/talk/2007/kelemen-2007-C5-Silent_Corruptions.pdf
> 

Thanks!

> It's quite possible (though unlikely) for a hard disk to suddenly
> return corrupted data without signalling a read error, and this is a
> possibility that raid controllers typically just ignores. And then you
> have the usual crop of software, firmware and hardware errors that can
> trash your data more or less silently.

It seems ZFS end-to-end checksums is not such a bad idea after all :)

> At a minimum, make sure you keep checksums of all files so you can
> verify their integrity.

Thank you for the feedback!

-- 

 / jakob