0.070: horton hears a hu

My sides hurt.

I ended last week rotflmao!, thanks to IBM's Charlie Andrews and his creative response to flash-based solid state storage (tape, he said...TAPE!). At the time, I figured that nobody could top that for the flat-out wackiest statement of the year.

Apparently, I underestimated Hu Yoshida.

Not content with his first round of uninformed comments about flash SSDs, HDS' so-called "chief technology officer" piled on a few more layers of baloney in an interview with IT Week UK's Dave Bailey:

IT Week:

What are your views on Flash memory storage, which EMC recently announced it would be putting onto its DMX systems?

Hu:

There are a number of problems with Flash memory. First, the price, which can be up to 20 times as much as spinning disks. Secondly, there’s supplier viability – there’s only a few vendors of this technology at the minute. You’ve also got to remember that Flash disks have a rewrite limitation and we need to have some diagnostics to predict when that limit could occur. For hard disks, we have self-monitoring analysis and reporting technology (Smart), but there’s nothing like that for Flash disks. What happens if you’re in the middle of a financial transaction and a write failure occurs, after a write commit? As for performance, just because it’s solid state doesn’t mean it would be any faster than a spinning disk. Remember all those interfaces between your application and the disk are slowing the data transfer rates, so it would be a good idea to benchmark your set-up.

What happens on a write failure, he asks?

LSHIPMP!

OK, well, I almost PMP...

Wait, let me catch my breath...

Come on, he can't be serious...I mean, it's not like disk drives don't suffer from the occasional write failure, yet somehow we manage not to lose data. At least, EMC arrays manage not to lose data - with multiple layers of protection and recovery.

Can it be that Hu is really that out of touch with reality?

 

hu needs a clue

Hu is flat out wrong about many of his assertions - at least, in the context of the enterprise flash drives that EMC is supporting. In fact, he's so wrong that frankly I'm surprised that IT Week UK would even listen to this prattle, much less print it. Guess they were the only ones who would listen any more.

Yet another case of the blind leading the deaf, I guess.

crazy little thing called raid

I'm sure that the vast majority of you that read my blog understand that storage arrays (and RAID controllers, for that matter) inherently handle disk write failures by design. In fact, most modern hard disk drives will remap bad blocks transparently, using spare tracks included specifically for that purpose. But if a write ever does fail hard, the RAID controller will still complete the I/O by updating the RAID parity on another drive. This is (by definition) sufficient to rebuild the failed write - whether it be a single block, or an entire drive.

This is precisely why we use RAID instead of JBOD today.

Enterprise-class flash drives are no different - like hard disks, they too will remap bad blocks into reserved flash space. And the controller's RAID logic will protect against failed writes to flash, should they ever occur, just like for hard drives.

So you don't have to worry about the world's economy screeching to a halt because of a write failure to a flash drive. EMC's got you covered.

By the way, Steve Todd, of CLARiiON fame, has provided a comprehensive look inside the CLARiiON RAID engine over on his blog, if you're interested.And if you really really care about the integrity of your data, you should read this post...

there are more flash drive than disk drive suppliers

Hu should get out more and do some shopping.

Today there are essentially only 4 disk drive manufacturers: Seagate, Hitachi, Samsung, and Western Digital.

And today there are at least 5 flash drive manufacturers, including SanDisk, Samsung, BitMicro, Mtron and of course STEC. A few more companies recently came out of stealth (you'll have to find them yourselves), and there are several more on the horizon (but I can't mention them either).

We clearly are at the beginning of a new industry, and the emergence of more suppliers will undoubtedly drive prices down.

flash is indeed smart

Despite Hu's repeated assertions to the contrary, enterprise flash drives do in fact provide SMART status, just like a disk drive.

And Symmetrix DMX leverages this SMART information just as it does for fibre channel and SATA hard drives, monitoring temperature, block remaps, retries, etc. In fact, the majority of SMART sense codes are identical for hard drives and flash drives. True, some don't apply (like spin speed), and there are a few new ones specific to flash (such as average # of rewrites). These allow the system to preemptively replace drives before components fail or they eventually wear out. Stuff you just have to have when your objective is to protect the information absolutely and provide the ultimate in availability and performance.

Hu seems to know so much about SMART, frankly, I'm flummoxed as to why he's not aware that it's supported by virtually every FLASH drive available on the market today.

flash is really really fast

Compared to a hard disk drive, flash is inarguably fast.

Sure, many of the run-of-the-mill laptop-type drives suffer from slow write performance (they can be slower than 5400 RPM drives even). But enterprise flash drives are by definition (and design) significantly faster than disk drives, for both reads and writes. And while Hu is correct that you have to match your application to the benefits of flash, and that you have to consider the inherent overheads of the array, controller and SAN, the implication that the performance benefits are limited are patently false.

In a Symmetrix, being able to deliver a Read Miss I/O in only a few microseconds longer than it takes to deliver a Read Hit I/O is a massive difference from the average 6 milliseconds it takes a 15K RPM hard drive to deliver a Random Read.

so what's really going on here?

Given that everything Hu seems to say about flash drives is wrong (and remember, he's supposed to be HDS' chief technology officer), I got to wondering how he could be so out of touch. More importantly, I wondered if Hitachi Japan (the actual developers of Hitachi's storage arrays) were as out of touch as Hu.

I'll take it as a given that the Hitachi Global Storage folks (the part of the conglomerate that makes hard disk drives) has no clue about flash SSD's. And it pretty much wouldn't matter anyway, since they're trying to sell that division to China as we speak (or so I've heard).

So what's up? Is Hitachi Japan not telling Hu what they know about flash, or are they really not working on it? Is Hu really out of touch with technology, or is he intentionally lying in interviews in order to mislead the public? Or maybe they're just not talking to each other any more - you'd think Japan would want him to stop embarrassing the company, since he's definitely not helping to Inspire The Next (IMHO).

Honestly, I don't know the answer. But if I were a customer or prospect of Hitachi (or Sun or HP) storage, I don't think I'd like any of those answers.

Then again, at least he didn't say that Hitachi was going to follow IBM's lead and use TAPE!

(With all due respect to Dr. Seuss) maybe Hu just needs a friend...

 

technorati tags: hu yoshida, flash drives, HHSNBN, SMART, flash vendors, EMC, Symmetrix, DMX, enterprise flash, enterprise storage, SSD, inspire the next, Hitachi, USP, USP-V, IBM, DS8000

Comments

[David Meiri]

Apparently Hu doesn't read the comments in his blog (see http://blogs.hds.com/hu/2008/01/ssd_flash_or_dram.html#comments.) He made all these false observations in his first blog after EMC announcement (was the sun in Hawaii too strong?). His readers tried to correct him (more gently than our anarchist, I must say), to no avail.

One of the comments read:
"According to STEC, and the 110 page ZeusIops operating manual, SMART is fully supported today and worn-out/bad pages are reported as bad “sectors” while spare pages are used to replace these bad pages." Go figure.

[the storage anarchist]

I agree, that's pretty embarrassing. It's been two months, you'd think he'd have found time to actually do some research into the subject by now.

[Stephen Foskett]

Barry... Samsung doesn't make enterprise drives - think Fujitsu! And you've also got Toshiba and (kinda) Excelstor. So that makes seven drive manufacturers.

Also, just how smart is SMART? There's an article for you... ;-)

[Willem]

I find it very hard to take someone serious who is belittling his colleagues that much.

[Nigel]

tut tut tut Barry. Picking on people - again!

Lets see of you do what you accuse Hu of not doing - listening to feedback you receive from readers.

PS. Its easy and somewhat childish to pick on others and make fun. You could at least pretend that you are 'helping' people who are 'misinformed', and give them a 101 on the subject to 'help educate' them. After all, educting someone raises and somewhat enobles them.