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Going Deep Inside Xserve Apple Drive Modules
adamengst writes "If you've had an Xserve drive fail, you may have considered saving some money by putting a replacement drive inside its Apple Drive Module. That may be a false economy, though. TidBITS explains why, while pinning Apple down on exactly what goes into Apple Drive Modules and why they cost so much more than bare retail drives."
Apple dude discovers that servers use, well, server class HDs and they cost more than normal ones.
Oh, and the 'sleds' that hold the HDs have some LEDs (cool!) and a controller board to work with the cooling system.
Like pretty much every other half decent server then.
I want a list of atrocities done in your name - Recoil
The gist of the article is "We asked Apple why they're more expensive, and took their word for it." It's just regurgitated marketspeak about how Apple tweaks the firmware for the optimal performance, has special rubber on the grommets of the ADM that is specific to each drive to reduce vibrations, and how off-the-shelf drives are unreliable, slow, noisy, and hot.
They don't make an effort to verify this information at all. Because Xserves won't run with commodity drives, they can't do a proper comparison to determine how much is truth and how much is smoke-up-the-ass from Apple. This is such an astroturf article, it doesn't even pretend to be anything otherwise.
That ain't no 3rd-party article, it's an Apple sales brochure.
Disgusting.
Fuck systemd. Fuck Redhat. Fuck Soylent, too. Wait, scratch the last one.
... nicely. Quoting TFA - "About a year ago, we bought an Intel-based Xserve with a pair of 80 GB SATA drives to act as our primary Web server. When the boot drive went flaky on us in October 2008, ... "
Welcome to pragmatism and reality - Drives fail all the times. So use cheaper drives in redundant mode, replace them with cheaper drives when they fail. You would have saved good amount of money even if the cheaper drives failed three time more than the costlier ones. (450$ for 1TB vs $100 for 1TB - from the same article.)
Having worked in the disk mines of IBM many years ago, the SCSI disk controller is somewhat your pixie dust but the real reason is the disks, heads and other parts for the SCSI drives came from IBM's best manufacturing facilities. The deathstar ATA drive's parts came from the lesser manufacturing facilities. In theory a SCSI disk should not be much better than ATA but the reality is the best made, more reliable parts go to the high end more profitable products.
And it also doesn't do a good job of explaining why the drive modules are so expensive. "Server-class" SATA drives? Big deal, if you want that, pay $30 more for a Seagate NS drive instead of the consumer-level AS model. Custom firmware? Again, big deal - every server mfr does that (my Seagate NS drives have HP firmware on them), and the article offer no numbers to indicate a qualitative improvement. Extra hardware in the carrier? Again, show me a net benefit for the extra money. Custom rubber grommets? Puh-lease. The quote I found most amusing was this: "A final fact to realize about the custom firmware in ADM drives is that the Xserve's Server Monitor software is designed to monitor about a dozen variables reported by the drive's firmware and report pre-failure warnings if those variables stray outside acceptable limits." Has this person never heard of SMART, and is he not aware that practically every drive made today implements it? It's hardly rocket science to write a SMART monitor.
The reason Apple (and every other server vendor) charges that much for drives is because that's what they want to do, and it's disingenuous for this guy to be spinning it as if Apple has something special in that regard.
Please stand clear of the doors, por favor mantenganse alejado de las puertas
This retarded fluff piece aside, the reason people buy (and pay a premium) for oem "blessed" hard drive replacements is because they JUST FUCKING WORK. If I save $100 on a hard drive, but spend two hours dicking with the raid controller to get it to play nice, or find out that it is in fact 2 mb smaller then the other drives, and now the raid won't rebuild, or has some firmware issue that I now need to rig up something to update, etc. I've lost money.
There is value in having everything already tested, and all your equipment in a "supported" configuration. When you have problems it makes it that much easier.
The fact that this article was apparently written by someone who does not know the difference between SAS and SATA makes it completely worthless. Clearly they are not qualified to admin the server they do have, much less write articles about the technical benefits of apple drives over other replacements.
The people who write these articles are stupid and contribute stupidity to IT in general.
1) Apple calls these beefier models "server-class" drives; you may also see terms like "RAID edition"
There is simply no data to back this up. The vendors themselves do NOT do sufficient testing to make these claims ergo Apple can not make these claims. This parallels the so-called better failure rates of SCSI/FC 'enterprise' drives and consumer SATA drives. In the FAST paper by Schroeder we see the following quote.
". . . we observe little difference in replacement rates between SCSI, FC and SATA drives, . . . ."
2) Firmware - the closest thing to an argument here is "may prevent Server Monitor from being able to report on the drive's health"
3) Carrier - "Apple also told me that the rubber grommets that hold the drive to the ADM carrier are chosen specifically to match each drive's vibrational characteristics."
This leaves out the most important thing. "So what" - ok if the drives vibrational characteristics are not matched what happens. Is it significant? Where is the data to say so?
4) Extensive testing - Essentially arguing that Apple does burn-in testing (which you could easily do yourself) however...again from the FAST paper:
"Contrary to common and proposed models, hard drive replacement rates do not enter steady state after the first year of operation. Instead replacement rates seem to steadily increase over time."
Drives act like mechanical devices NOT electronic devices.
In general - have you EVER read an article with so many "may"'s and "possibly"'s? There's very little here that could be risk assessed (giving some kind of probability of some consequence) - which means it USELESS as advice. The parts that actually IMPLY some kind of probability/consequence are not well supported by the studies with the largest sample sizes.
It's really NOT that informative.
Informative:
Yes. You can use off the shelf SATA drives in your ADMs. They will work just fine, and any special firmware tweaks Apple has done in the drive firmware are completely unnoticeable in any real world environment, if they're there at all.
I've replaced 500GB SATA drives in ADMs with 1TB off the shelf "consumer grade" Seagate drives. They work flawlessly, with no performance penalty. I'd trust them EXACTLY as much as I would Apple-supplied drives - which is to say, not at all without RAID mirroring and a good backup. ALL hard drives fail.
Not Informative:
The article. They didn't do anything but trust what some low-level Apple rep gave them. They did NO actual testing, the whole thing is purely anecdotal.
I don't know what your pay works out to in an hourly rate, but $275 per drive saves me money over the do-it-yourself opportunity cost of the time it would take to, well, do it myself. And it's warranted, so when it fails I can send a lackey to deal with the RMA bullcrap and slap the new component in. The current American work force isn't all that bright, so if I can buy a component that allows me to hire a $17/hr drone to install and maintain it then the extra few tens of thousands for equipment pays for itself within the first year over equipment that needs a real professional to maintain it.