| Author |
Message |
Rita Ä Berkowitz
Guest
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 Posted:
Tue Nov 30, 2004 3:32 am Post subject:
Re: What am I doing wrong ??? Or is Adaptec 21610SA just a c |
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news.tele.dk wrote:
| Quote: |
Yes it cost pennies, in Danish currency:
Maxtor Atlas 10K 146Gb = 3760,78
Maxtor DiamondMax 160Gb = 606,80
So what youre saying is: "The speed of SCSI disks is more than 6
times that of SATA".
Eg. when we buy an array of disk with 2 SCSI disks it will match our
SATA array
with 12 disks (when we eventually get hold of a recent controller).
|
What I am saying is you bought some respectable hardware at a premium price
to accomplish a specific job. You castrated the system by anchoring it with
SATA and you are now seeing the pitfalls. I gave you practical real world
advice from experience that is tough to accept because you have a good
investment in SATA. My suggestion of SCSI doesn't look appealing because of
the initial cost. When you factor in ease of deployment, reliability,
longevity, and performance you quickly realize it pays for itself in short
order.
A few people and a resident troll gave you a few options. I gave you my
opinion on what to do, go SCSI and don't look back. The troll gave you a
typical answer of throwing hardware at it till you get the results you want.
Does that sound logical to you? Does that sound like a suggestion from
someone that has real world experience? Here's his quote
"What you're going to have to do though is try the various boards in your
server until you find one that hits your performance objectives or have
gone through all of them"
This is great advice if you have a source for unlimited hardware that isn't
going to cost you anything. Sure, take this route and spend another grand
or two and you will be right were you could have been in the first place
without the performance, SCSI.
I apologize for sounding so harsh, but this is your baby. When it takes a
crap, it's you that has the aggravation, expense, and egg on your face, not
me. I've been down this road many times with customers that bought into the
SATA crap pushed on them by inexperience hardware pushers and bailed them
out for a substantial price.
If you are really insistent on using SATA find someone that has a server
deployed that meets your specs and pick their brain for ideas of what
hardware to buy before you spend any more. Good luck in your endeavors.
Rita
--
http://www.geocities.com/ritaberk2003/ |
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Rita Ä Berkowitz
Guest
|
| Posted:
Tue Nov 30, 2004 3:39 am Post subject:
Re: What am I doing wrong ??? Or is Adaptec 21610SA just a c |
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news.tele.dk wrote:
| Quote: |
Yes it cost pennies, in Danish currency:
Maxtor Atlas 10K 146Gb = 3760,78
Maxtor DiamondMax 160Gb = 606,80
So what youre saying is: "The speed of SCSI disks is more than 6
times that of SATA".
Eg. when we buy an array of disk with 2 SCSI disks it will match our
SATA array
with 12 disks (when we eventually get hold of a recent controller).
|
What I am saying is you bought some respectable hardware at a premium price
to accomplish a specific job. You castrated the system by anchoring it with
SATA and you are now seeing the pitfalls. I gave you practical real world
advice from experience that is tough to accept because you have a good
investment in SATA. My suggestion of SCSI doesn't look appealing because of
the initial cost. When you factor in ease of deployment, reliability,
longevity, and performance you quickly realize it pays for itself in short
order.
A few people and a resident troll gave you a few options. I gave you my
opinion on what to do, go SCSI and don't look back. The troll gave you a
typical answer of throwing hardware at it till you get the results you want.
Does that sound logical to you? Does that sound like a suggestion from
someone that has real world experience? Here's his quote
"What you're going to have to do though is try the various boards in your
server until you find one that hits your performance objectives or have
gone through all of them"
This is great advice if you have a source for unlimited hardware that isn't
going to cost you anything. Sure, take this route and spend another grand
or two and you will be right were you could have been in the first place
without the performance, SCSI.
I apologize for sounding so harsh, but this is your baby. When it takes a
crap, it's you that has the aggravation, expense, and egg on your face, not
me. I've been down this road many times with customers that bought into the
SATA crap pushed on them by inexperience hardware pushers and bailed them
out for a substantial price.
If you are really insistent on using SATA find someone that has a server
deployed that meets your specs and pick their brain for ideas of what
hardware to buy before you spend any more. Good luck in your endeavors.
Rita
--
http://www.geocities.com/ritaberk2003/ |
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Tim Boyer
Guest
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| Posted:
Tue Nov 30, 2004 4:11 am Post subject:
Re: What am I doing wrong ??? Or is Adaptec 21610SA just a c |
|
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On Mon, 29 Nov 2004 17:39:11 -0500, "Rita Ä Berkowitz" <ritaberk2O04@aol.com>
wrote:
| Quote: | news.tele.dk wrote:
Yes it cost pennies, in Danish currency:
Maxtor Atlas 10K 146Gb = 3760,78
Maxtor DiamondMax 160Gb = 606,80
So what youre saying is: "The speed of SCSI disks is more than 6
times that of SATA".
Eg. when we buy an array of disk with 2 SCSI disks it will match our
SATA array
with 12 disks (when we eventually get hold of a recent controller).
What I am saying is you bought some respectable hardware at a premium price
to accomplish a specific job. You castrated the system by anchoring it with
SATA and you are now seeing the pitfalls. I gave you practical real world
advice from experience that is tough to accept because you have a good
investment in SATA. My suggestion of SCSI doesn't look appealing because of
the initial cost. When you factor in ease of deployment, reliability,
longevity, and performance you quickly realize it pays for itself in short
order.
|
<delurking>
In about six months, I'm going to be in the market for a 2TB system, and will
have to make some of the same choices. Rita, _why_ is SCSI so much better than
SATA?
Thanks much,
--
tim boyer
tim@denmantire.com |
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Rita Ä Berkowitz
Guest
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| Posted:
Tue Nov 30, 2004 8:59 am Post subject:
Re: What am I doing wrong ??? Or is Adaptec 21610SA just a c |
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Tim Boyer wrote:
| Quote: |
In about six months, I'm going to be in the market for a 2TB system,
and will have to make some of the same choices. Rita, _why_ is SCSI
so much better than SATA?
|
Tim, not knowing exactly what your requirements are, I'll just repeat in the
simplest terms what I said in a previous post, "When you factor in ease of
deployment, reliability, longevity, and performance you quickly realize it
pays for itself in short order." That said, depending on your requirements
SATA might be better for you if you have minimal demands and expectations.
Rita
--
http://www.geocities.com/ritaberk2003/ |
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Eric Gisin
Guest
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| Posted:
Tue Nov 30, 2004 9:47 am Post subject:
Re: What am I doing wrong ??? Or is Adaptec 21610SA just a c |
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"Rita Ä Berkowitz" <ritaberk2O04@aol.com> wrote in message
news:10qns3vhd6ook15@news.supernews.com...
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Toomas Soome
Guest
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| Posted:
Tue Nov 30, 2004 1:03 pm Post subject:
Re: What am I doing wrong ??? Or is Adaptec 21610SA just a c |
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Tim Boyer wrote:
| Quote: |
In about six months, I'm going to be in the market for a 2TB system, and will
have to make some of the same choices. Rita, _why_ is SCSI so much better than
SATA?
|
current data transfer rates (lets not argue about possible future
numbers, I have some but never done research for them):
SATA: 150Mb/s (up to 1.5Gb/s?)
SCSI: 320Mb/s
SAS: 3Gb/s (roadmap up to 12Gb/s)?
FC-AL: 2Gb/s (roadmap up to 10Gb/s ?)
reliability:
SCSI MTBF 1,200,000 hours, many SATA drives only run to 600,000 MTBF
(http://searchstorage.techtarget.com/infoCenter/tip/0,294276,sid5_gci1001942_tax294586,00.html)
and some real numbers as well regarding to reliability:
Deskstar 7K400, http://www.hitachigst.com/hdd/support/7k400/7k400.htm
Error rate (non-recoverable) 1 in 10E14
Start/stops (at 40° C) 50,000
Ultrastar 15K147 http://www.hitachigst.com/hdd/support/15k147/15k147.htm
Error rate (non-recoverable) 1 in 10E15
Start/stops (at 40° C) 50,000
in general, SATA will not replace SCSI anytime "soon", high end SCSI
will still outperform SATA in many terms... but SATA does definitely
have it's place as well.
toomas
--
Kissing a smoker is like licking an ashtray. |
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Tim Boyer
Guest
|
| Posted:
Tue Nov 30, 2004 5:19 pm Post subject:
Re: What am I doing wrong ??? Or is Adaptec 21610SA just a c |
|
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On Tue, 30 Nov 2004 10:03:46 +0200, Toomas Soome <Toomas.Soome@microlink.ee>
wrote:
| Quote: | Tim Boyer wrote:
In about six months, I'm going to be in the market for a 2TB system, and will
have to make some of the same choices. Rita, _why_ is SCSI so much better than
SATA?
current data transfer rates (lets not argue about possible future
numbers, I have some but never done research for them):
SATA: 150Mb/s (up to 1.5Gb/s?)
SCSI: 320Mb/s
SAS: 3Gb/s (roadmap up to 12Gb/s)?
FC-AL: 2Gb/s (roadmap up to 10Gb/s ?)
reliability:
SCSI MTBF 1,200,000 hours, many SATA drives only run to 600,000 MTBF
(http://searchstorage.techtarget.com/infoCenter/tip/0,294276,sid5_gci1001942_tax294586,00.html)
and some real numbers as well regarding to reliability:
Deskstar 7K400, http://www.hitachigst.com/hdd/support/7k400/7k400.htm
Error rate (non-recoverable) 1 in 10E14
Start/stops (at 40° C) 50,000
Ultrastar 15K147 http://www.hitachigst.com/hdd/support/15k147/15k147.htm
Error rate (non-recoverable) 1 in 10E15
Start/stops (at 40° C) 50,000
in general, SATA will not replace SCSI anytime "soon", high end SCSI
will still outperform SATA in many terms... but SATA does definitely
have it's place as well.
toomas
|
Thanks much, Toomas! I'm replacing a _very_ old Clariion, fairly lightly used,
so anything's gonna be an improvement. But I value reliability over
performance, and it looks like I'd be smart to stick with SCSI - for now, at
least.
--
tim boyer
tim@denmantire.com |
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J. Clarke
Guest
|
| Posted:
Tue Nov 30, 2004 8:35 pm Post subject:
Re: What am I doing wrong ??? Or is Adaptec 21610SA just a c |
|
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Toomas Soome wrote:
| Quote: | Tim Boyer wrote:
In about six months, I'm going to be in the market for a 2TB system, and
will
have to make some of the same choices. Rita, _why_ is SCSI so much
better than SATA?
current data transfer rates (lets not argue about possible future
numbers, I have some but never done research for them):
SATA: 150Mb/s (up to 1.5Gb/s?)
|
No. 150 M_B_/sec. 3 Gb/sec hardware is shipping, not that it has any
real-world relevance. All allocated to a single device. No drive on the
market, SCSI or SATA, is capable of sustained transfers at anything close
to this rate, so it's adequate for any purpose.
Shared among up to 15 devices. No clear advantage to SCSI here unless you
give each device a separate channel, which gets hugely expensive very
quickly.
| Quote: | SAS: 3Gb/s (roadmap up to 12Gb/s)?
|
Again, though, shared. And you're interchanging bits and bytes. That's
about 300 MB/sec.
| Quote: | FC-AL: 2Gb/s (roadmap up to 10Gb/s ?)
|
Again, shared. And that's roughly 200 MB/sec when you allow for overhead.
| Quote: | reliability:
SCSI MTBF 1,200,000 hours, many SATA drives only run to 600,000 MTBF
|
This has nothing to do with SATA vs SCSI--look up the specs on WD Raptors
and you'll find that same 1,200,000 MTBF. If you want enterprise-class
storage get enterprise-class storage.
(http://searchstorage.techtarget.com/infoCenter/tip/0,294276,sid5_gci1001942_tax294586,00.html)
And if you look at the Raptor you'll find again 1 in 10E15.
| Quote: | in general, SATA will not replace SCSI anytime "soon", high end SCSI
will still outperform SATA in many terms... but SATA does definitely
have it's place as well.
|
While this is true, it is not for any of the reasons you stated. SCSI does
have a few real advantages--there's a lot more in the way of
enterprise-class host adapters and array cabinets and the like available
for one thing. For another it allows _much_ longer cables. For a third,
for now the fastest SATA drives do not match the speed or capacity of the
fastest SCSI drives, and for 10K RPM SATA drives there's no second
source--that last is a marketing issue, not a technical one--there's no
reason that 15K RPM SATA drives can't be produced by multiple vendors, it's
just that so far they've decided not to.
Further, it's all rather far afield as the problem the OP is describing
isn't really addressed by any of this. His basic problem remains that he
got a substandard array controller.
--
--John
Reply to jclarke at ae tee tee global dot net
(was jclarke at eye bee em dot net) |
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Anton Rang
Guest
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| Posted:
Tue Nov 30, 2004 8:57 pm Post subject:
Re: What am I doing wrong ??? Or is Adaptec 21610SA just a c |
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"news.tele.dk" <no@email.dk> writes:
| Quote: | So what youre saying is: "The speed of SCSI disks is more than 6 times that
of SATA".
|
You're being overcharged for the SCSI disks....
But there are significant differences between SCSI and SATA in both
performance and reliability. They're not intrinsic to the interface,
rather to the cost structure of each.
SATA disks typically have less error checking internally than SCSI,
increasing the likelihood of undetected errors. Not a big deal if
you're working with 1 disk; more serious when you have 10 and
mission-critical data.
Some SATA disks don't have enough RAM to store the whole sector flaw
map at once. Random access across those disks can waste a whole
(extra) disk rotation to read the flaw map for a track. The drive
will cache some of these, and this works fine for home use, but in a
database environment this can be a 2x performance hit.
SCSI and FibreChannel disks, at this point, are engineered for
reliability, because the market buying them are customers who care
about that. SATA is engineered for low cost, period.
Anton |
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Marcin Dobrucki
Guest
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| Posted:
Tue Nov 30, 2004 9:19 pm Post subject:
Re: What am I doing wrong ??? Or is Adaptec 21610SA just a c |
|
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Rita Ä Berkowitz wrote:
| Quote: | Tim, not knowing exactly what your requirements are, I'll just repeat in the
simplest terms what I said in a previous post, "When you factor in ease of
deployment, reliability, longevity, and performance you quickly realize it
pays for itself in short order." That said, depending on your requirements
SATA might be better for you if you have minimal demands and expectations.
|
Sorry, a question from a lurker. How does the SCSI interface improve
reliability of the disks? We are replacing SCSI disks by the dozen.
The only thing that I can think of here is that someone is using
home-grade SATA drives in enterprise environment.
The only reason I don't see more SATA disks being deployed locally is
that they usually are running at 7200rpm and not 10000 or 15000 like the
new scsi stuff, and hence access times are longer. This carries some
performance penalty for our systems indeed. But ease of deployment is
hardly an issue as the disks are hot-plugable, disk hardware fails
regardless of interface type, and frankly.. scsi prices are ridiculous.
/Marcin |
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Marcin Dobrucki
Guest
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| Posted:
Tue Nov 30, 2004 9:32 pm Post subject:
Re: What am I doing wrong ??? Or is Adaptec 21610SA just a c |
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Toomas Soome wrote:
| Quote: | reliability:
SCSI MTBF 1,200,000 hours, many SATA drives only run to 600,000 MTBF
(http://searchstorage.techtarget.com/infoCenter/tip/0,294276,sid5_gci1001942_tax294586,00.html)
|
www.google.com -> "enterprise sata mtbf" --> first match
http://www.wdc.com/en/products/current/retailkits/wd740gdrtl.asp
==> MTBF=1'200'000 hours
Lets not compare disks aimed at desktop market, and enterprise grade
hardware.
/Marcin |
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Peter
Guest
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| Posted:
Tue Nov 30, 2004 9:44 pm Post subject:
Re: What am I doing wrong ??? Or is Adaptec 21610SA just a c |
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| Quote: | No. 150 M_B_/sec. 3 Gb/sec hardware is shipping, not that it has any
real-world relevance. All allocated to a single device. No drive on the
market, SCSI or SATA, is capable of sustained transfers at anything close
to this rate, so it's adequate for any purpose.
|
Not true:
http://www.fcpa.com/products/hard-drives/mau-3147-15k-rpm/specifications.html
Data transfer rate To/from media 147 MB/s
| Quote: | SCSI: 320Mb/s
Shared among up to 15 devices. No clear advantage to SCSI here unless you
give each device a separate channel, which gets hugely expensive very
quickly.
|
Perfomance issues rarely relate to a sequential read/write speed alone. Most
likely they reflect poor random IO operations. Putting interface maximum
speed at the first place, is a mistake. |
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Nik Simpson
Guest
|
| Posted:
Tue Nov 30, 2004 9:58 pm Post subject:
Re: What am I doing wrong ??? Or is Adaptec 21610SA just a c |
|
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Marcin Dobrucki wrote:
| Quote: | Rita Ä Berkowitz wrote:
Tim, not knowing exactly what your requirements are, I'll just
repeat in the simplest terms what I said in a previous post, "When
you factor in ease of deployment, reliability, longevity, and
performance you quickly realize it pays for itself in short order." That
said, depending on your requirements SATA might be better for
you if you have minimal demands and expectations.
Sorry, a question from a lurker. How does the SCSI interface
improve reliability of the disks?
|
The SCSI interface per-se doesn't, but because SCSI & FC drives are designed
for "enterprise class" applications they go through a different & more
rigourous quality control process than consumer drives. It's this more
comprehensive QC that is responsible for better reliability rather than the
interface. So in the future there is no technical reason why the SATA drives
cannot meet the same reliability leves as SCSI, but in doing so they would
have to adopt the same QC & testing procedures which would erode the price
difference between them and other more "reliable" types of drive.
--
Nik Simpson |
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Peter
Guest
|
| Posted:
Tue Nov 30, 2004 10:18 pm Post subject:
Re: What am I doing wrong ??? Or is Adaptec 21610SA just a c |
|
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| Quote: | No. 150 M_B_/sec. 3 Gb/sec hardware is shipping, not that it has any
real-world relevance. All allocated to a single device. No drive on the
market, SCSI or SATA, is capable of sustained transfers at anything close
to this rate, so it's adequate for any purpose.
|
Not true:
http://www.fcpa.com/products/hard-drives/mau-3147-15k-rpm/specifications.html
Data transfer rate To/from media 147 MB/s
| Quote: | SCSI: 320Mb/s
Shared among up to 15 devices. No clear advantage to SCSI here unless you
give each device a separate channel, which gets hugely expensive very
quickly.
|
Perfomance issues rarely relate to a sequential read/write speed alone. Most
likely they reflect poor random IO operations. Putting interface maximum
speed at the first place, is a mistake. |
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Anton Rang
Guest
|
| Posted:
Tue Nov 30, 2004 10:58 pm Post subject:
Re: What am I doing wrong ??? Or is Adaptec 21610SA just a c |
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|
"Peter" <peterfoxghost@yahoo.ca> writes:
He said *sustained* data rates. You only get 147 MB/sec while you're on one
track. As soon as you have to switch heads or seek, there's a gap in the data
stream.
The only benchmark I could find on that drive in a couple of minutes
of hunting shows 80 MB/sec, which is still very good.
http://neasia.nikkeibp.com/wcs/leaf/CID/onair/asabt/fw/323039
-- Anton |
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