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Old May 14th 20, 04:15 AM posted to
Grant Taylor
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Posts: 14
Default Do you think the days of the hard drive is finally over?

On 5/13/20 6:17 PM, Yousuf Khan wrote:
So Seagate and other makers are getting ready to introduce 20 TB HDD's
to the market. According to Seagate, its fastest drives are capable of
sustained 250 MB/s transfers (if you believe them). It would take 30+
hours to entirely fill such a drive with data at maximum speed! Is that
too much time, no matter how much capacity you are getting?

No, that is not too much time for some, if not many use cases.

Is that basically unusable capacity?

Absolutely not.

I know you can say that a drive that large would be filled over a
number of years, and no one would be filling it all up in one go.

There will be some people that will fill it in almost one go.

But that's probably true in a home environment, but what about an
enterprise environment?

Some enterprises (think Backblaze) will fill drives in a few days. They
have very specialized ways to write data to hundreds / thousands of
drives. They write things to each drive to capacity and then move on to
the next drive. (There is obviously redundancy elsewhere in the
application stack.) As such, they fill the drives in what some would
consider one go.

What if that drive were part of a RAID array, and one of those drives
failed and needed to be replaced? In RAID parity, the entire drive
has to be written to, because the parity is required on all drives at

It depends on what type of RAID technology is used. ZFS's RAID has the
unique ability to only re-synchronize the amount of the drive that was
used, not the entire drive.

Aside: ZFS is very impressive.

Imagine you start synchronizing a replacement drive like that, and
it takes 30 hours to do that?

And? This happens. I have a friend & colleague that's waiting on a
RAID array to rebuild and has estimates of nearly 200 hours.

That's a long enough time that it's conceivable another drive within
that array would fail too, before it's had a chance to completely
resync with the array.

This is, and has been for 10–20 years. That's one of the reasons that
RAID-6 and higher RAID levels are popular.

So sure, you can get that capacity with an HDD, but should you
really be storing your data on something that slow?

Sure. Anything that only needs to access a subset of the content but
wants a deep catalog is a perfect use for such a drive.

HDD's can't get much faster.

What is a HDD? Why does an SSD /not/ qualify as a HDD?

What about the various holographic storage methods that IBM (and others)
have experimented with over the last 30 years.

There have been multiple times in the past that hard drive manufacturers
have experimented with, and shipped to customers, drives that have
multiple sets of heads for increased performance.

Also, I'm quite certain that each and every time that someone has said
that something can't get faster, it does.

Grant. . . .
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