Erik’s point, which is that today people
don’t know why they’re using RAID. It
may very well be the same with flash.
GReG GanGeR: The general model of
search engines is you want to have a
certain cluster that handles a given
load. When you want to increase the
load you can handle, you essentially
replicate that entire cluster. It’s the
unit of replication that makes management easier.
When it’s Christmas Eve and the
service load is low, you could actually power down many of the replicas.
While I do not believe this has been
done yet, it seems like the thing to do
as power costs continue to be a larger
issue. In these systems there is already
a great degree of replication in order
to provide more spindles during high-load periods.
mache cReeGeR: You all said that there
is low-hanging fruit to take advantage
of. Are there things you can do today as
profound as server virtualization?
steVe KLeiman: The companion to
server virtualization is storage virtualization. Things like snapshots and
clones take whole golden images of
what you’re going to run and instantaneously make a copy so that only the
parts that have changed are additional.
You might have 100 virtual servers out
there with what they think are 100 images, but it’s only one golden image
and the differences. That’s an amazing savings. It’s the same thing that’s
going on with server virtualization; it’s
almost the mirror image of it.
What has come about over the last
few years is the ability to share the infrastructure. You may have one infrastructure, but it’s still a hundred different images, you’re actually not sharing
the data. That’s changed in the last five
years since we have had cloning technology. This allows you to get this tremendous so-called thin-provisioning
eRic BReWeR: I disagree with something said earlier, which is that it’s becoming hard to delete stuff. I feel that
deletion is a fundamental human right
because it gets to the core of what is
private and what rights you have over
data about you. I want to be able to delete my own stuff, but I also want to be
able to delete from groups that have
data about me that I no longer trust.
A lot of this is a legal issue, but I hate
to feel like the technical things are going to push us away from the ability to
steVe KLeiman: That’s a good point.
While it’s hard to expend the intellectual effort to decide what you want to
delete, once you’ve expended that effort, you should be able to delete. The
truth is that it’s incredibly hard to delete something. Not only do you have
to deal with the disks themselves, but
also the bits that are resident on the
disk after you “delete” them, and the
copies, and the backups on tape.
One of the things that is part of our
product right now, and which we continue to work on, is the ability to fine-grain encrypt information and then
throw away the key. That deletes the
information itself, the copies of the in-
invented by iBm in 1956, the first model 350 disk drive contained 50 24-inch diameter disks and stored a total of 5mB. iBm later added
removable disk platters to its drives; these platters provided archival data storage.
PHO TOGRAPH BY MARK RICHARDS, FROM THE BOOK CORE MEMORy, CHRONICLE BOOKS