problems with Hitachi 1TB SATA drives

[Thomas Hurst]

* Jeremy Chadwick (koitsu at FreeBSD.org) wrote:

> * I'm left questioning why a disk manufacturer would process drives
> (by this I mean the manufacturing process) differently based on their
> transport type.  It would cost a *huge* amount of money to have
> separate fabs for SCSI, SAS, and SATA/PATA.

One one side you've got consumer drives, where price and capacity are
king; you want cheap mass produced large, fairly slow disks, made for
modest duty cycles.

On the other you've got drives that live in servers in their thousands,
running 24/7 on IO heavy workloads, where performance and reliability
are king and price is far less important; you end up with smaller,
sturdier platters, more powerful actuators and motors, and more
extensive testing, not to mention slower growth in capacity.

> * All this leads me to the topic of backups.  Hard disks are growing
> in capacity at a rate which the backup industry cannot follow.  It's
> getting to the point where you have to buy hard drives to back up the
> data on other hard drives, but anyone with half a brain knows RAID is
> not a replacement for backups.

So you back up one disk to another using proper backup tools and not a
RAID system.  Have some disks off-site, some offline, and you end up
with something that's "good enough" for most people.

It'll do me until we get memory diamond, anyway ;)

> * SCSI is outrageously expensive even in 2007.  I have yet to see any
> shred of justification for why SCSI costs so much *even today*.  It
> costs only a smidgen less than it did 15 years ago.

They don't look that expensive to me; sure, when you compare capacity
with SATA it's expensive, but the platters are several times smaller,
they spin faster, they have better testing, fancier materials, smarter
firmware... for a server, why wouldn't you spend a few times more for
something with 4x faster seeks and 4x lower failure rates?

I have servers with 28 disks and 12 disk RAID-0's.  I'm happy to pay
extra so I'm not replacing and rebuilding every week :)

> * SCSI is on its way out.  Seagate recently announced that
> they'll no longer be supporting SCSI products, possibly by the end of
> next year:
> 
> "Seagate has announced that by next year they will no longer be
> supporting SCSI product and will be moving customers to the SATA
> interface."
> http://www.horizontechnology.com/news/market/market_perspective_storage_04-11-2007.php
> 
> I'm willing to bet others will follow suit.

They almost certainly only mean U320; I severely doubt SAS is going
anywhere.  I really hope so, since Seagate are currently the only
company making 15kRPM 2.5" SAS disks (afaik).

I do find it surprising they're doing this so soon though.  I would have
thought they'd have long term support contracts for various server
vendors who've only very recently started moving over to SAS.  I guess
they're expecting their stockpiles to keep people in replacements for
the next few years.

-- 
Thomas 'Freaky' Hurst
    http://hur.st/