ATA Reliability: Seagate, WD, Maxtor

On Sat, 09 Apr 2005 06:22:05 GMT, flux wrote:

I don't know how much of it is true,

we know

but I do know that ATA drives are a
lot faster and a lot more reliable than some here think they are.

Yeah the STR is good & so is the idea of lower overhead but throw a
couple of disk intensive tasks at an ATA disk or array & it chokes.
ATA is fast enough for light duty use but chokes in a stressfully
environment. ATA RAID is often downright pathetic.

There is a difference between something basically working outside of a
few occasional, recoverable quirks over a lifetime that seems mostly
OK 'cause there isn't really much important on it anyway and doesn't
get used all that much & something doing exactly what it's supposed to
do all the time and exceeding expected life while being able to
sustain much harder use (longer head use).

Unfortunately, while better drives tend to be scsi or fibre that's not
to say every one is and has been bulletproof. I'll take a reliable
ATA over a crummy older SCSI drive any time. My druthers is with more
solid scsi or FC models any day of the week & twice on sundays.

I know I'm not going to change your mind. I've seen your kind of
predictable responses too often. They always come from either troll
or inexperience.

Curious George wrote:
On Sat, 09 Apr 2005 06:22:05 GMT, flux wrote:


I don't know how much of it is true,


we know


but I do know that ATA drives are a
lot faster and a lot more reliable than some here think they are.


Yeah the STR is good & so is the idea of lower overhead but throw a
couple of disk intensive tasks at an ATA disk or array & it chokes.
ATA is fast enough for light duty use but chokes in a stressfully
environment. ATA RAID is often downright pathetic.

There is a difference between something basically working outside of a
few occasional, recoverable quirks over a lifetime that seems mostly
OK 'cause there isn't really much important on it anyway and doesn't
get used all that much & something doing exactly what it's supposed to
do all the time and exceeding expected life while being able to
sustain much harder use (longer head use).

Unfortunately, while better drives tend to be scsi or fibre that's not
to say every one is and has been bulletproof. I'll take a reliable
ATA over a crummy older SCSI drive any time. My druthers is with more
solid scsi or FC models any day of the week & twice on sundays.

I know I'm not going to change your mind. I've seen your kind of
predictable responses too often. They always come from either troll
or inexperience.


Whoops - apologies for the earlier posts which were sent in error.

What I can add to this discussion is that the enterprise vs. desktop
differences are tangible and not simply a case of sampling yields, as
has been the case with speed ratings for semi-conductors.

Bandwidth and I/O issues aside, on the topic of reliability, the key
issue is the MTBF and bit error rates, which are broadly similar.
However, my understanding are the tests which lead to these figures are
different.

It is expected that in some applications SCSI/FC drives are
running 24/7 at high intensity, therefore the test figures quote for this.

The profile of general desktop usage is completely different, and the
tests are geared for the expected pattern of usage in this market, i.e.
sporadic usage, probably more power cycles, etc.

Also, the enterprise stuff tends to have more comprehensive fault
analysis, i.e. SMART and the like, which can be of use to the RAID
vendor in pre-emptively signaling a failing drive. General operating
system support for this stuff is patchy and in (S)ATA drives will
normally only be of use in a post mortem scenario, or through some
dedicated diagnostic software.

Regards,

K

In article ,
Bill Todd wrote:

flux wrote:
In article ,
Bill Todd wrote:


Fact: ATA drives max out at 7200 rpm, while SCSI/FC drives max out at
15,000 rpm. That gives SCSI drives a 2+:1 advantage in rotational
latency right off the bat.


That doesn't necessary mean they are faster. In fact, they can even be slower.

No, you moron: it *does* necessarily mean they are faster, for at least

No, it doesn't.

that particular metric. And if you check out sequential bit rates from
the platters, you'll find that current SCSI/FC drives are faster there
as well.



As for reliability, I'll let you read the paper that you previously
neglected to: it's quite thorough in its assessment of the differences.


Apparently not.

Certainly sufficiently thorough to put your mistaken impressions to rest.

It wasn't expressing an impression.

In article ,
Bill Todd wrote:

flux wrote:

...

I'm not sure I believe you.

Then you might benefit from actually looking at the material he cited

And that changes facts how?

In article ,
Curious George wrote:

On Sat, 09 Apr 2005 06:22:05 GMT, flux wrote:

I don't know how much of it is true,

we know

but I do know that ATA drives are a
lot faster and a lot more reliable than some here think they are.

Yeah the STR is good & so is the idea of lower overhead but throw a
couple of disk intensive tasks at an ATA disk or array & it chokes.

SATA certainly doesn't share this problem.

ATA is fast enough for light duty use but chokes in a stressfully
environment. ATA RAID is often downright pathetic.

SATA doesn't share this problem either. Is it that different or could it be that ATA is not as bad as you think?

Unfortunately, while better drives tend to be scsi or fibre that's not
to say every one is and has been bulletproof. I'll take a reliable
ATA over a crummy older SCSI drive any time. My druthers is with more

I'm confused. Some people seem to be arguing you can't say reliable and ATA in the same sentence.

solid scsi or FC models any day of the week & twice on sundays.

I know I'm not going to change your mind. I've seen your kind of
predictable responses too often. They always come from either troll
or inexperience.

Or they happen to be true.

In article ,
"K.P.King" wrote:

It is expected that in some applications SCSI/FC drives are
running 24/7 at high intensity, therefore the test figures quote for this.

The profile of general desktop usage is completely different, and the
tests are geared for the expected pattern of usage in this market, i.e.
sporadic usage, probably more power cycles, etc.


Actually, it's not. Desktop drives are in use 24/7. Just check out video
recorders like Tivo. These things record video 24/7. AFAIK, they are
just ordinary ATA drives.

Another thing relates to desktop computers. If there are to be backed
up, that usually happens at night and therefore they must be left
running. So I suspect it's actually unusual for desktop computers--at
least those in a workplace--not to be running 24/7.

On the other hand, I wonder if takes more out of a drive to powered up
and then powered down again and again. Seems like 24/7 usage is less
usage, strangely enough.

Also, the enterprise stuff tends to have more comprehensive fault
analysis, i.e. SMART and the like, which can be of use to the RAID
vendor in pre-emptively signaling a failing drive. General operating
system support for this stuff is patchy

What operating system has builtin support?

flux writes:

Actually, it's not. Desktop drives are in use 24/7. Just check out video
recorders like Tivo. These things record video 24/7. AFAIK, they are
just ordinary ATA drives.

The issue is not the platters rotating but head move (constant
seeking). Put an ordinary ATA disk in a busy newsserver and watch it
explode.

mkb.

Matthias Buelow writes:
The issue is not the platters rotating but head move (constant
seeking). Put an ordinary ATA disk in a busy newsserver and watch it
explode.

Good thing I did not spend time watching, as nothing exploded since
I run ordinary (WD400, if that counts) drives in my newsfeeders. ;-)
Sure, there is a bad drive every now and then, but drive failures
happen with expensive SCSI drives, too. The rate does not worry me.

I found that I just don't get much more than 130-140 I/O transactions
per drive on average, but I had that issue with the expensive SCSI drives
before, too. More spindles take care of that for my applications.

Back to the original subject: I had bad series with most manufacturers
at some time over the years and I am currently using WD, because their
RMA handling works without trouble and because their drives are pretty
fast, so I have no reason to switch at this time.

Michael

On Tue, 12 Apr 2005 04:09:24 GMT, flux wrote:

In article ,
Curious George wrote:

On Sat, 09 Apr 2005 06:22:05 GMT, flux wrote:

I don't know how much of it is true,

we know

but I do know that ATA drives are a
lot faster and a lot more reliable than some here think they are.

Yeah the STR is good & so is the idea of lower overhead but throw a
couple of disk intensive tasks at an ATA disk or array & it chokes.

SATA certainly doesn't share this problem.

sorry but PS drives are the same regardless of interface, unless you
mean raptors specifically. SATA kills the lower overhead advantage
PATA had over SCSI.

ATA is fast enough for light duty use but chokes in a stressfully
environment. ATA RAID is often downright pathetic.

SATA doesn't share this problem either. Is it that different or could it be that ATA is not as bad as you think?

I'm not taking about sharing the bus, just raw disk performance with
more complex/demanding usage than typical desktop usage patterns. If
you're thinking of raptors specifically state that. Raptors are not
typical SATA drives. They are closer to apples & apples comparison
but then the price is similar also to scsi while at the same time
being newer/less mature/less proven track record.

Right now I'm using/evaluating/testing Seagate 7200.8's in arrays.
Even though the synthetic benchmarks are basically lining up to what
they're supposed to be it still chokes very easily. Very
disappointing...

I'm sorry but I don't see the sense of raptors and a good 3ware card
or whatever. I don't care whether performance & reliability is
competitive or not. 10K SCSI makes more sense to me. It's more
mature, more flexible, better supported, has a longer track record,
etc. and costs about the same. 1st gen 10k sata compared to 6th or
7th gen 10k scsi. Come on.

Unfortunately, while better drives tend to be scsi or fibre that's not
to say every one is and has been bulletproof. I'll take a reliable
ATA over a crummy older SCSI drive any time. My druthers is with more

I'm confused. Some people seem to be arguing you can't say reliable and ATA in the same sentence.

It's not either/or. There are bum models of every interface.
Although the best SCSI tends to beat the best ATA reliability wise
hands down, but then you pay for that. But if you go through more ATA
drives in the lifetime of a machine, cluster, etc, (even a small
amount more) you pay for that too- it ultimately costs much more
despite the lower up front costs like parts.

In many businesses even marginal increases in reliability are a big
deal because of the massive costs of support, maintenance and of
service interruption. One's attitude depends on individual tolerance
of risk & fiddling around. ATA doesn't have to be totally unstable
garbage to be/seem unsuitable to many ppl & environments.

solid scsi or FC models any day of the week & twice on sundays.

I know I'm not going to change your mind. I've seen your kind of
predictable responses too often. They always come from either troll
or inexperience.

Or they happen to be true.

very cute.

In article ,
Matthias Buelow wrote:

flux writes:

Actually, it's not. Desktop drives are in use 24/7. Just check out video
recorders like Tivo. These things record video 24/7. AFAIK, they are
just ordinary ATA drives.

The issue is not the platters rotating but head move (constant
seeking). Put an ordinary ATA disk in a busy newsserver and watch it
explode.

That's probably just a fraction of the work a Tivo machine requires of it.