high-end SCSI vs best SATA ?

In article ,
(Andrei Ivanov) wrote:

wrote:
You should include duty cycle when looking at MTBF. Depending of the
SATA drive the MTBF is based on a duty cycle of anywhere from 20% to
60%, while SCSI and SAS drives are usually rated with a duty cycle of
100%.

Seagate describes these SATA disks (ST3250824NS) in their propaganda as

"the industry's first nearline-ready drive with nearline-class
reliabilty and integration"

which probably does not mean "24/7/365".


In reality, it does.

In article .com,
wrote:

Seagate loosely defines
Online as 24x7 power on, highly random, high IOPs, high duty cycle
Nearline as 24x7 power on, highly random, low IOPs, low duty cycle
Low-Cost Server as 8x5 power on hours, more sequential, frequent
start/stop, low duty cycle.

So, they are expected to be 'on' all the time, just not very busy.

Although they work fine if they are busy all the time.

In article ,
Maurice Volaski wrote:
In article ,
which probably does not mean "24/7/365".


In reality, it does.

Does this mean 24 hours a day 365 days a year for 7 years, or what?
Shouldn't it be 24/7/52. With some roundoff error.
Or maybe just 24/365.

carl
--
carl lowenstein marine physical lab u.c. san diego

Maurice Volaski wrote:
In article .com,
wrote:

Seagate loosely defines
Online as 24x7 power on, highly random, high IOPs, high duty cycle
Nearline as 24x7 power on, highly random, low IOPs, low duty cycle
Low-Cost Server as 8x5 power on hours, more sequential, frequent
start/stop, low duty cycle.

So, they are expected to be 'on' all the time, just not very busy.

Although they work fine if they are busy all the time.

If Seagate is just repackaging its online drives with SATA interfaces,
then yes. Otherwise, you should expect a much lower MTBF if you run
them at too high a duty cycle with higher than expected failures
starting to show up in less than 6 months.

"Carl Lowenstein" wrote in message
...
Does this mean 24 hours a day 365 days a year for 7 years, or what?
Shouldn't it be 24/7/52. With some roundoff error.
Or maybe just 24/365.
AFAIK, 24/7/365 means 24hrs a day, 7 days a week and 365 days a year.
-G

In article ,
NoSpam wrote:

"Carl Lowenstein" wrote in message
...
Does this mean 24 hours a day 365 days a year for 7 years, or what?
Shouldn't it be 24/7/52. With some roundoff error.
Or maybe just 24/365.
AFAIK, 24/7/365 means 24hrs a day, 7 days a week and 365 days a year.
-G

Not the "executive 24/7"; 24 hours a week, 7 months a year.

-- mrr

In article ,
NoSpam wrote:

"Carl Lowenstein" wrote in message
...
Does this mean 24 hours a day 365 days a year for 7 years, or what?
Shouldn't it be 24/7/52. With some roundoff error.
Or maybe just 24/365.
AFAIK, 24/7/365 means 24hrs a day, 7 days a week and 365 days a year.

The way I understand weeks and years, 365 days a year implies 7 days a
week. But of course this is just an illogical phrase that has crept into
the language. Every so often it bubbles to the top of annoying phrases.

carl
--
carl lowenstein marine physical lab u.c. san diego

Carl Lowenstein wrote:

In article ,
NoSpam wrote:

"Carl Lowenstein" wrote in message
...
Does this mean 24 hours a day 365 days a year for 7 years, or what?
Shouldn't it be 24/7/52. With some roundoff error.
Or maybe just 24/365.
AFAIK, 24/7/365 means 24hrs a day, 7 days a week and 365 days a year.

The way I understand weeks and years, 365 days a year implies 7 days a
week. But of course this is just an illogical phrase that has crept into
the language. Every so often it bubbles to the top of annoying phrases.

How about "lock and load", when it should be "load and lock"...you
must load before you can lock.

--
+----------------------------------------------------------------+
| Charles and Francis Richmond richmond at plano dot net |
+----------------------------------------------------------------+