

HGST gets closer to shipping 10TB HDD - tanglesome
http://www.zdnet.com/article/hgst-gets-closer-to-shipping-10tb-hdd/

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fiatmoney
The 8 TB HDDs available now take a full _15 hours_ or so for a linear scan at
max speed. God help you if you ever need to rebuild a RAID array made of them;
the risk of an additional failure in say a RAID5 or RAID6 configuration is
just too high.

We're nearing the point at which the throughput relative to the capacity and
the risk of failure or corruption makes further capacity less and less useful,
unless you're doing some pretty sophisticated replication, validation, &
caching.

~~~
moe
_the risk of an additional failure in say a RAID5 or RAID6 configuration is
just too high._

Two disk failures in the same array within 15 hours is very rare.

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ghshephard
Unless the root cause is something to do with the array - flakey controller,
or power supply.

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craigyk
these kinds of problems may cause the array to fail, but won't necessarily
lose data, right? If you have a ZFS pool and a faulty controller causes the
pool to fail, ie. "losing" three disks in a raidz2 vdev, my guess is that you
would just replace the faulty card and reimport the pool and chances are
things would be OK... no?

~~~
DiabloD3
ZFS can mostly handle that. It will try to recover any data it can, and
rebuild whatever it can. Due to how paranoid ZFS is designed, it will survive
edge cases like this much better, which is also why I like deploying it here
even at home.

And if it can't recover it? You can prove it by failed checksum check. This is
why, in my opinion, ZFS is so much better than all other file systems: if it
fails, you can prove it instead of just sorta vaguely questioning everything
because you can't tell but you suspect it, and it slowly drives you insane.

Once you try ZFS, you never go back.

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ars
Wow, hard drives are getting complicated!

You have to write 256MB to change a single bit?

And you have various zones, and you have to keep track of where data is
written, because it's not written in order, and can be on any zone?

You would need some sort of battery backed scratch/cache area to pull this
off, so that you don't have to write very often, otherwise I can't imagine
performance will be very good.

~~~
ryan-c
Having maybe 16 to 64 GB of flash storage (for writeback cache) would probably
make a significant difference here. I think over the next five to ten years
tiered storage will probably go mainstream.

~~~
mtanski
Tiered storage is already here. If you're using block storage in the cloud
those guys are already do all sorts of optimizations (for their costs) that
include tiering. And on your own desktop / own server side you can do this
today on Linux with bcache or dm-cache. Works great for databases.

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kondro
Before people make too many comments about the complexity and speed of these
drives, it is important to realise that these drives are designed for append-
mostly archival of data.

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atYevP
Yev from Backblaze here -> gimme gimme gimme gimme!

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mtanski
We spent a bit of time talking about about these "shingled drives" at the
LSF/MM summit earlier in the week in Boston. Storage is becoming a more
fascinating topic with so many technologies (SSDs, shingled disk, non-volatile
memory) and so new open source solutions (Ceph, Luster).

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toolslive
One of the problem with these HDDs is that you still have the same number of
spindles. These spindles now need to cover a lot more data, and they were
already `challenged`

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qt_scientist
Yup, RAID is being replaced by object storage for large scale systems. Last
week, HGST acquired object storage startup Amplidata...

