Well, I discovered that early on, and my suspicion is that it might have something to do with the fluid bearing, viscosity breakdown, or something like that...
Anyway, I asked IBM, and here the result of that exchange:
(I cut my e-mail address and the name of the IBM rep, because
I don't want to get him fired if he disclosed more than he was supposed to...)
Me, myself and I: I have an IDE-to-SCSI RAID which
takes 6 EIDE HDs, creates a RAID-5
array from them, and presents the
resulting storage to the host
computer as if it were a single, large
Currently this array is loaded with 6
IBM 34GXP 34 GB Deskstar drives,
however I want to increase the
capacity, and was thinking of
replacing these drives with 6 of the
120GXP Deskstar drives.
The recent troubles with the 60GXP
series drives made me wonder
about potential reliability problems.
Then I read the technical specs of
the 120 GXP series, and there I find
the following item, notably under the
"Recommended power-on hours
Does this mean this drive is not a
reliable choice to be used in a RAID
that's running 24*7 ?
I cannot find similar exclusions on
either Maxtors or WesternDigital's
drive specs, and the later specifies a
non-recoverable error rate that's an
order of magnitude better, and
claims a minimum of 50k start/stop
cycles, while the IBM drive claims an
average of 40k start/stop cycles.
Are IBM's specs just particularly
conservative in their estimates or is
the side effect of the drive being
more silent and marginally faster
than the WD1200JB, that the
reliability suffers and that it loses the
ability to be used in a 24*7 set up?
What about all the people who'd like
to use a big drive like this in various
slimline rackmount internet servers?
Will they have to go elsewhere?
No IBM ATA drive has been rated for use
in a 24/7 environment. In most cases, only
SCSI drives are rated for this type of usage.
ATA RAID is a relatively new market. It may
work, but it is not tested by IBM in this
Me, myself and I:
thanks a lot for your answer. I would strongly suggest that IBM
rethinks their strategy, however. While ATA RAIDs are relatively
new (at least in terms of common visibility, they have been on
the market for at least four years now), rackmount LINUX servers
are not. There must be thousands, if not millions of 1U or2U
PC based rackmount Linux servers in server farms that are rented
out to people who want to host their own web site or e-store
at a managed site. This was even acknowledged in the product
description of your new 60GB TravelStar drive, which is now rated
for "continuous use" in "blade servers".
Similarly many offices that just need a workgroup e-mail and
intranet server for low data volume applications commonly use
a desktop PC, often even one that's no longer a current model,
because serving a few intranet web pages is a low CPU power
job, so even a relatively outdated machine can take care of this.
Hardly anyone uses SCSI drives in such circumstances, particularly
since Microsoft software makes it a pain to deal with SCSI, while
ATA is comparatively speaking a breeze.
This is not something that we can change.
This is a barrier that is part of the IDE infrastructure There is no way
for us, nor any other manufacturer, to overcome this.
This is now, and probably will be for quite some time, the primary
difference between IDE and SCSI.
The Travelstar 60GB seems to be an exception to the rule. How this was
accomplished I do not know.
Me, Myself and I:
with all due respect, but I don't understand your answer.
I don't see how an electrical interface specification and
data transfer protocol (EIDE/ATA) has any influence on the
reliability of the drive, which is largely a matter of
mechanics, read/write heads, electronics, lubrication, etc.
The fact that one drive uses and EIDE/ATA interface doesn't
make it necessary that it can only endure 333h power-on per
month, while a SCSI drive can work in a 24*7 environment.
That SCSI drives may be faster due to the built-in smarts,
etc. is a completely different story.
What seems to be much more believable is that in order to be
able to compete on price, which is key in the desktop market,
not the same amount of quality engineering goes into the
mechanics and electronics of the EIDE/ATA drives that goes into
the more expensive SCSI drives.
The fact that the TravelStar 60GB drive can withstand
a 24*7 operational environment shows only that on a drive like
this the margins are fat enough to put the relevant quality
into the mechanism.
Several other manufacturers advertise their higher-capacity
EIDE/ATA drives for use in work group servers (which run 24*7)
or for the use in rack-mount internet appliances (which also run
24*7). So either IBM is more cautious, or their quality is better.
Needless to say, without access to data proprietary to each of
these companies, there is no way of telling which is the case.
Now should I have missed a point as to *why* EIDE/ATA drives
cannot be built as reliable as SCSI drives, I'd sure like to know.
Me, Myself and I:
I think I'll have to go with a WD drive, because I can't gamble
with my server's reliability, and so access speed will have to take
second priority. After all, the WD1200JB is no slouch either.