New hard disk architectures

George Macdonald wrote:
Two different initiatives though: the HDD mfrs are trying to extend the
life of rotating platter systems; Intel's Robson is a fast startup
"technology" http://www.pcworld.com/news/article/0,aid,123053,00.asp.


Well, flash isn't going to extend the life of the platters, it's only
good for the fast startup. In order to extend platter life you'd need
ram mostly.

Yousuf Khan

GSV Three Minds in a Can wrote:
It would allow an even deeper level of coma than 'Hibernation' I guess
... you could turn the power off or pull the wall plug and still resume
where you left off. If the speed was right (which could be arranged)
then maybe you could use it as some place to store %bloatwaredir% and
get even cold boots going PDQ.


The problem you'd have with such a dynamically updated hibernate file is
that if you keep writing to the flash drive, it will quickly lose its
entire limited allocation of write cycles. The hard disks and ram have
unlimited write cycles (virtually), flash doesn't.

However, in a laptop environment, with a battery backup already
available, I can see them possibly going into save-to-ram (standby)
mode, followed by a save-from-ram-to-flash mode. You can completely turn
off the hard disk when power is lost, and make all updates only to the
flash disk, which would then proceed to update the disk when power is
restored. Very much like a journalled filesystem.

Yousuf Khan

On Fri, 16 Dec 2005 20:06:21 -0500, Yousuf Khan wrote:

GSV Three Minds in a Can wrote:
It would allow an even deeper level of coma than 'Hibernation' I guess
... you could turn the power off or pull the wall plug and still resume
where you left off. If the speed was right (which could be arranged)
then maybe you could use it as some place to store %bloatwaredir% and
get even cold boots going PDQ.


The problem you'd have with such a dynamically updated hibernate file is
that if you keep writing to the flash drive, it will quickly lose its
entire limited allocation of write cycles. The hard disks and ram have
unlimited write cycles (virtually), flash doesn't.

However, in a laptop environment, with a battery backup already
available, I can see them possibly going into save-to-ram (standby)
mode, followed by a save-from-ram-to-flash mode. You can completely turn
off the hard disk when power is lost, and make all updates only to the
flash disk, which would then proceed to update the disk when power is
restored. Very much like a journalled filesystem.

Yousuf Khan

A solution looking for a problem...

With all of that in place, there's really no gain on the play: a laptop with a
functional battery shouldn't scram to disk just because it lost its mains
source, it should just pop a warning and keep on running. If the operator
decides to bail, (s)he can simply enter Hibernate. End of story, no flash
required.

At best, all the extra flash and code to use it could even hope to accomplish
is to save a few milliwatts of battery life when shutting down...

/daytripper

In comp.sys.ibm.pc.hardware.storage Yousuf Khan wrote:
Arno Wagner wrote:
This has been around for some time. The flash does not really help,
unless you write very littel to disk. Personally I think SRAM
and batteries are a better choice, also because flash has relatively
low number of write cycles before it breaks. Not so bad with a disk
mapped 1:1 to flash (e.g. because it is entirely flash), but a serious
problem if a small flash has to buffer all writes to a large disk.
Maybe they are just trtying to create disks that break after 2
years or so...
Note that SRAM+battery has been around for at least a deacde in more
expensive RAID controllers, so the basic idea is old.

I don't think they're talking about using flash in the sense of a
dynamic disk cache, but as a static disk cache, or a ramdisk in other
words. Namely, they're aiming to cache the boot sequence into the
flashdisk to speed up boot times.

That would not make much sense IMO.

As to 4096 Byte sectors, I frankly do not see the point. Multi-sector
transfer stream more than 512 bytes on one go already. Clustering also
provides the possibility to use larger than 512Byte as allocatioon
unit.

Well, they explained it in article, they're saying that the reason this
is needed is because with only 512 bytes you don't have enough bits for
error correcting code with today's big hard disks.

That is nonsense. The size of the disk has no impact on the per-sector
error corection. Maybe they mean that with 4096 byte sectors they
can use more efficient codes.

Arno

On Fri, 16 Dec 2005 19:51:27 -0500, Yousuf Khan wrote:

George Macdonald wrote:
Two different initiatives though: the HDD mfrs are trying to extend the
life of rotating platter systems; Intel's Robson is a fast startup
"technology" http://www.pcworld.com/news/article/0,aid,123053,00.asp.


Well, flash isn't going to extend the life of the platters, it's only
good for the fast startup. In order to extend platter life you'd need
ram mostly.

I did not mean reduce wear of the platters but extend the lifetime of hard
disks in general as a mass storage solution, i.e. delay the switch over to
flash as a replacement for hard disks. It gets them a foot in the door
with the technology too... hopefully, from their POV, fending of Sandisk
et.al. from taking over the mass storage market eventually.

--
Rgds, George Macdonald

On Sat, 17 Dec 2005 16:24:38 -0500, George Macdonald
wrote:

On Fri, 16 Dec 2005 19:51:27 -0500, Yousuf Khan wrote:

George Macdonald wrote:
Two different initiatives though: the HDD mfrs are trying to extend the
life of rotating platter systems; Intel's Robson is a fast startup
"technology" http://www.pcworld.com/news/article/0,aid,123053,00.asp.


Well, flash isn't going to extend the life of the platters, it's only
good for the fast startup. In order to extend platter life you'd need
ram mostly.

I did not mean reduce wear of the platters but extend the lifetime of hard
disks in general as a mass storage solution, i.e. delay the switch over to
flash as a replacement for hard disks. It gets them a foot in the door
with the technology too... hopefully, from their POV, fending of Sandisk
et.al. from taking over the mass storage market eventually.

Until cost per bit for flash at least enters the same arena as magnetics -
never mind approaches parity - I doubt the magnetic media companies are all
that worried about flash encroaching in their bread-and-butter markets...

Oh, wonders of a journalled filesystem... BTW, you can do the same tricks
with NTFS.

I'm afraid, you folks argue two different concepts:

1. Filesystem robustness against power failure or system reset;
2. Complete system state restore across power-off (which is achieved with
hibernation, but requires some time for writing the state).

IIRC, OS/360 allowed the applications to restart from a saved checkpoint,
but it's not what's discussed here.

If anybody hopes to restore complete system state after an arbitrary power
failure (as if it didn't happen), you're out of luck without battery backup.

"Robert Redelmeier" wrote in message
. net...
In comp.sys.ibm.pc.hardware.chips daytripper
wrote:
Because that very hiberfil.sys *is* being updated, and until it has
completed
successfully, the hiberfil.sys *is not* up to date. But that isn't the
point.

Why does "up to date" matter? Does it need to be within the
last 17ms of an AC cycle? For many PC purposes, a _consistant_
image for 15 seconds ago would do.

Once a system has successfully created the hiberfil.sys and shut
down, you can kick the plug all you like, but when you finally
get tired of that and plug it back in and hit the power switch,
the system should successfully return from hibernation.

Actually, I was more brutal while testing FreeBSD: I kicked
the plug towards the end of kernel compiles. In 3 out of 4
trials, the compile restarted cleanly, taking a combined 30
sec longer. Once it had to be restarted from scratch. In no
case was the filesystem damaged, thanks to Kirk McCusack's
SoftUpdates (essentially carefully ordered disk writes).

-- Robert

On Sat, 17 Dec 2005 18:32:22 -0500, daytripper wrote:

On Sat, 17 Dec 2005 16:24:38 -0500, George Macdonald
wrote:

On Fri, 16 Dec 2005 19:51:27 -0500, Yousuf Khan wrote:

George Macdonald wrote:
Two different initiatives though: the HDD mfrs are trying to extend the
life of rotating platter systems; Intel's Robson is a fast startup
"technology" http://www.pcworld.com/news/article/0,aid,123053,00.asp.


Well, flash isn't going to extend the life of the platters, it's only
good for the fast startup. In order to extend platter life you'd need
ram mostly.

I did not mean reduce wear of the platters but extend the lifetime of hard
disks in general as a mass storage solution, i.e. delay the switch over to
flash as a replacement for hard disks. It gets them a foot in the door
with the technology too... hopefully, from their POV, fending of Sandisk
et.al. from taking over the mass storage market eventually.

Until cost per bit for flash at least enters the same arena as magnetics -
never mind approaches parity - I doubt the magnetic media companies are all
that worried about flash encroaching in their bread-and-butter markets...

OTOH, do people really pay more for 200GB drives? Ok, I bought one on
BlackFriday for $29 (I would have bought a smaller drive at $29). Will
people pay for a flash drive it it were a similar price and half the
capacity? ...forgetting the write-cyle issue. My bet is yes.

BTW, what happened to MRAM? I thought we'd be swimminng in it by now. ;-)

--
Keith

On Sat, 17 Dec 2005 22:47:41 -0500, Keith wrote:

On Sat, 17 Dec 2005 18:32:22 -0500, daytripper wrote:

On Sat, 17 Dec 2005 16:24:38 -0500, George Macdonald
wrote:
I did not mean reduce wear of the platters but extend the lifetime of hard
disks in general as a mass storage solution, i.e. delay the switch over to
flash as a replacement for hard disks. It gets them a foot in the door
with the technology too... hopefully, from their POV, fending of Sandisk
et.al. from taking over the mass storage market eventually.

Until cost per bit for flash at least enters the same arena as magnetics -
never mind approaches parity - I doubt the magnetic media companies are all
that worried about flash encroaching in their bread-and-butter markets...

OTOH, do people really pay more for 200GB drives? Ok, I bought one on
BlackFriday for $29 (I would have bought a smaller drive at $29). Will
people pay for a flash drive it it were a similar price and half the
capacity? ...forgetting the write-cyle issue. My bet is yes.

Geeze...."forgetting that the drive has a profound problem with wear-out"
kinda changes the nature of the comparison....But, ok, at only twice the
price, you possibly could be right - if in fact there's some perceivable
performance advantage, because capacity is still important. But at the current
rate of cost-per-bit closure, even you'll be an old gummer before that
happens.

BTW, what happened to MRAM? I thought we'd be swimminng in it by now. ;-)

ahahahahahahahahaha!

Reminds me of the annual visits from the FeDRAM folks...

/daytripper

On Sat, 17 Dec 2005 22:47:41 -0500, Keith wrote:

OTOH, do people really pay more for 200GB drives? Ok, I bought one on
BlackFriday for $29 (I would have bought a smaller drive at $29). Will
people pay for a flash drive it it were a similar price and half the
capacity? ...forgetting the write-cyle issue. My bet is yes.

US$29 for a 200GB drive? New? I gotta get a truckload of these :P They
are going for like at least US$100 a piece here.

--
A Lost Angel, fallen from heaven
Lost in dreams, Lost in aspirations,
Lost to the world, Lost to myself