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Getting Rid of the Disks
Kneht writes "Dan's Data has an interesting article on what it would cost to get rid of your HDDs and replace them with SSDs because hard drives suck. Several aspects are examined, such as required UPS, compact flash, etc. Read the article and you may get a new appreciation for your lowly 7200rpm drive."
Funny, I was just thinking that I should start using 120GB disks as my removable media.
Right now, hard drives are the right cost/benefit compromise. Could they be better? Yes. Would it cost a lot more? Yes. When the second changes, let me know.
I just upgraded all my hard disks to bigger models :(
Get rid of my High Density Diskettes (HDD) and replace them with Single Sided Diskettes (SSD) ???
That would be expensive, because the old drives are expensive when you find them from collectors on eBay, besides which I would have far less storage capacity (180K instead of the 1.44M I have now).
It reminds me of the short period back in the day when I ran my BBS on a three floppy diskette PC system. The third floppy diskette was a 5-1/4" 720K drive (quad density) but users complained about the slowness, and this was 1200 baud users.
There's a lot of research going on in this area. In particular, there's a newly completed Ph.D. thesis studying a persistent memory/disk hybrid filesystem for linux, named conquest. The performance is quite impressive, although the reports are that it's nowhere near ready for use - the term 'researchware' gets tossed around a lot.
Basically, by storing metadata and files smaller than 1mb in memory, the typically accessed information is much more convenient, and the larger files left on the disk are typically in their 'best case' (it's much more common to read large files than to write them, and typically they're read in some near-linear order: if you watch a moving, you may skip once or twice, but then it's sequential reads). The combination seems to work quite well: We compare Conquest's performance to ext2, reiserfs, SGI XFS, and ramfs, using popular benchmarks. Our measurements show that Conquest incurs little overhead compared to ramfs. Compared to disk-based file systems, Conquest achieves 24% to 1900% faster performance for working sets that fit in memory, and 43% to 96% faster performance with working sets larger than the memory size. .
Video for Online Dating Profiles
They may not be perfect, but they are cheap. Also, I don't know about you guys, but I don't really need much faster storing devices.
Oh yeah, maybe we could collect some money for the person who wrote this, and send him/her to a writing school or something.
"But you can't buy SSDs for ordinary PCs.
Well, you can, but you don't want to. For two reasons."
Horrible horrible.
I'm finding that the lack of a universal DVD standard has left me looking at HDDs as my removeable media of choice as well. CDRs are nice and cheap, but I have files that would span multilpe CDRs. It's a little bit of a hastle to have to WINRAR up my data into small chunks, only to have to UNRAR it back into oen big chunk. DVDs aren't readable everywhere. I'd love to see faster solid state storage available at a price competitive with today's HDDs, but alas, it's just no there. I already have a great deal of respect from my 7200RPM HDDs
There are lies, damned lies, and statistics.
http://ask.slashdot.org/article.pl?sid=0
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Help my mini cause: My journal
SSDs are good for research purposes and Software Developer Kits. I think Intel's Explorer 2 SDK used to have 128 MB on board, which is useful for Assembly programming.
I remember when we used to program Motorola 6800... hehe...
Consensus is good, but informed dictatorship is better
I don't understand the hard drive bashing. Sure, it isn't as fast as DDR, but it's faster than any other storage media... It's not only faster, but cheaper as well.
In addition, I've had many power supplies and entire motherboards die in the same period as my hard drives have been operating. The best part of all is that they have very obvious signs when they are beginning to die, as well.
Hard drives are not the fastest or most reliable piece in you computers, but they are definately not the worst or slowest. Who here can find ECC DDR RAM for anywhere near $1/GB?
Slashdot gets worse every day... Pipedot: News for nerds, without the corporate slant
When you look at something like this, it makes $5000 for 20GB seem like a conservative estimate.
They could use FRAM (Ferromagnetic Random Access Memory)
It is as fast as RAM, but is non-volatile. Oh, and its endurance is unlimited. Right now they aren't big enough, but a the technology improves...
lynx -dump http://slashdot.org/ | grep "ead the article"
required UPS, compact flash, etc. Read the article and you may get a
loop" (read the article.) The goofy loop put about seven miles between
Two mentions of "read the article" on the front page. Are they trying to start a fad?
First attempt at being a math nazi....
shouldn't this be "I think I'll keep my magnetic drives and spend my $99,900 on something else."
I used to have a cool sig, back when I cared
"RAM costs more than disk". There. Now you don't need to read the story, which is probably /.ed by now anyway.
High-speed Road Trip (18.000KPH)
100,000 is not the same number as 1,000,000. Thanks.
With everyone upgrading, I bet there is a glut of used mem chips. Why not create a drive to 'recycle' these chips into some kind of SSD?
I find it amusing that it mentioned using a RAM based swapfile. Doesn't that defeat the purpose of a swapfile???
This guy mentions that compact flash dies after 100,000 to a million rewrites... and that you'll reach that surprisingly quickly if you put your swap file on it.
It seems highly unlikely that any sane person on any desktop system would choose to spend money on compact flash to use as swap, when they could spend less money and buy dram instead - which shuld be faster.
Anyway potentially you only need fast solid state diskspace for your operating system and main applications, since few people need that sort of speed on their 'data files'. I could build a bootable linux box that ran off a 256Mb compact flash - doesn't seem like it'd be too bad at all.
...they offer permanent stable storage. In the meantime there are all of these hacks to back the SSD with a magnetic disk, battery backups, etc.
In those cases, you're better off loading up on RAM and relying on the buffer-cache to make the disk slowness transparent.
Of course, you could be in a position where you already have 4GB of RAM stuck in a machine and it runs an x86 processor and it's still too slow. Then you're up shit creek unless you can deal with a measely 100MB/sec RAID solution. ;)
x86_64 any day now...
/me twiddle thumbs
The tandy sensationII had a 212 hard drive while my current system has 512 megs of ram. If I upgraded such a beast with my current amount of ram I would have twice as much ram as hard drive space. I still have my old 3.2 gig and 540 meg hard drives in a drawer in my room. I am thinking of using these again in a FreeBSD server. With ram the way it is today I can just put a shitload of ram on the server and set it up to load the whole hard drive in memory.
I remember a 3 year old maximumPC magazine which mentioned something about a ramdisk. Its an external scsi device that had 2 gigs of ram and a powersupply to keep its contents from being erased. Basically the computer saw it as a fast hard disk. It was very fast but got poor remarks because in a castrophic power outage your whole virtual disk is gone. Also the store space is very tiny. However with my comments above about specific servers this might make sense. With a price close to 30k it was very expensive and it was this that created the poor review.
A web server that does not containt a database does not need alot of disk space. Just apache, the os, a java2EE sdk, or javascript, or perl and thats it. All the content is created automatically by cgi scripts or java depending on what the webadmin uses. A ramdisk might be used for a highend website if the disk is the bottleneck. My old 3.2 gig drive has the same amount of ram as these 2-4 gig ramdrives. I can easily create a workstation or webserver with this.
A ramdisk today might be perfect because ram is so cheap and it would be alot cheaper.
http://saveie6.com/
Until SSDs get an order of mangitude cheaper, HDDs will continue to rule! For the thousands that SDDs cost, you can built a huge striped RAID of quick 120 GB drives that will perform more than fast enough for any existing applications. Paintbrush and minesweeper will run like they've never run before.
We create tons of video and always are hungry for backup. What we've done is to simply save our old hard drives as we upgrade and put the old ones to use in those $6.00 IDE removable cartridges as backup media. We mostly have 2-3 year old 20-40GB drives. We also have bought 5400rpm 120GB drives for incredibly cheap on Pricewatch as well...
We figure, as a backup, HDDs last just as long as any other magnetic medium. Because they mostly sit unused on a shelf, we're not that concerned about MTBF of the drive mechanisms. When we do use a backup, we still copy to our RAID/Server before using the files. The backup drives rarely see much use.
We have CD/DVD writers, but really only use them when sending stuff to clients. With the price of hard drives, it's hard to justify anything else as a backup medium.
If I wanted high speed and relability then I would just setup a 0+1 Raid system using 120GB for next to no money. However my questions is why do we need this much bandwidth off disk. Sure in things like video editing I can see the need and in that case I can invest in a Fibre Channel Array, or any modern HDD on SCSI can sustain 50Mb/s.
.02p
However for the average desktop why do I need speed? It won't get MP3's off my hard disk any faster and my OS might take 5 seconds less to boot. Overall I can't see the need for 99.9% of users to have really really fast storage. If we do need it then setup some sort of Ram Disk
Just my
Rus
Cheap UK and US VPS
maybe when he said "DDR", he was using it to cover ALL forms of RAM, go fuck yourself, next time say something that has some value to add, not just bash what he said.
Last I checked, you would only have to spare one chip worth of space to store the parity information, regardless of how many chips are being used to begin with.
-Lucas
I have noticed a performance increase when I have a seperate hard disk or partition for my operating system/programs. It seems to me that a lot of geeks do this. Have a fast hard disk for applications and a slower bigger hard disk for data. Memory is cheap enough now that I don't often even need to use virtual memory. I find the only time I need more system memory is for real time video processing. I don't even need it for audio anymore.
Wouldn't there be some benefit in having about 2 gigs of memory just for running the operating system and a seperate/cheaper storage for your large files? I seem to recall google running everything on DRAM.
Could someone explain to me why we don't have a portion of non-volitle memory for our operating system/programs?
-Rob
why would you want to put swap on a ramdrive? Why not just do something like.. USE THE RAM.
Swap's only purpose is to account for lack of ram.
Once again the need for legacy free PC's is made clear. I for one would be very willing to toss my PC and existing software out the window in exchange for a PC with 200 times the capabilities.
As for the hard-drive/ram/other-memory issue specifically, I think it is imperative that we unify the memory architecture. By treating the data that is typically stored on the hard drive the same as data typically stored in ram infinite new possibilities are opened.
Brandon Bloom
http://brandonbloom.name
He obviously knows his stuff but a few more drafts and an editor would have done wonders for this article.
Laws are for people with no friends.
I bought a 120gb 3.5 inch drive ($100) a couple months ago, and put it in an external firewire drive case ($50) and hooked it up to my computer. It's portable, has massive storage (relatve to most other removable storage, at least), has fast transfer speeds, comparable to other removable media, at least.
The plus is that I can always remove the drive and put a different one in if 120gb ever becomes "small".
alias uptime="echo '5:33pm up 22342352324 days, 6:28, 2124315623 users, load average: 2432.40, 12312.31, 123123.19'"
Seriously, I have IDE and SCSI drives that are about 10 years old (capacity is obviously small - in the 200 - 500mb range) and have almost no bad sectors; they still do a reliable job in routers and other boxes that don't require a lot of storage. Meanwhile, newer drives of 2Gb or larger regularly require replacements. Then, there's the problem of recent drive capacities being too large for the BIOSes of my "deprecated" computers, not to mention SCSI connector standards that change more often than the MTV Top 10.
The real problem, for an end-user, though, is the excessively generous storage capacities; as Cringely once pointed out, unless you are a graphic artist, your personal data probably fits well within 500Mb of storage. Why the hell is it that the smallest drives I can purchase nowadays are around 30Gb (120Gb for SCSI), at a time when my data storage needs still have not exceeded that 500Mb per user quota? And, no, my workstations do not suddenly have a use for larger drives either.
One cannot help but notice how manufacturer warranties reflect the lower quality, as well. Where we used to have 5 year warranties (which, in practice, meant that the drive actually performs well for about 10 years), current offerings are guaranteed for 1 year and last exactly that. There's been several recent cases e.g. with IBM's glass drives, where a replacement is required within 6 months from purchase.
I don't know about you, but I have better things to do than constantly wasting money on purchasing replacement drives and time on reinstalling everything on the new drive, only to find out that the BIOS cannot use such large drives, and cursing that I had to purchase a drive whose capacity is exactly 100 times what I can use.
Message to drive manufacturers: Gimme reliable and quiet 2 - 4Gb drives, using the good old 50-pin connectors in both IDE and SCSI flavours, but providing all the modern refinements of Ultra DMA100, etc. and guaranteed for 5 years or more. Make them affordable too. We don't want any more stinky throw-away media storage, thanks you.
Software is not supposed to be about how to work around a useability issue. - Ken Barber
... You should at least give props to [H] who posted this 36 hours ago.
The price per meg on current harddrives is RIDICULOUSLY low, we're all spoiled.
It's basically a dollar a GIG, or less... a 200 gig HD costs 200 bucks.
I'd be willing to pay $200 for a TWENTY gig solid state drive. Ten times the cost, but worth it... too bad no such thing is available.
~Berj
As seen in this Scientific American article (among too many others) the cost per megabyte measured in dollars per megabye back in the early 1990s. which seems to be where SSDs are right about now. Presuming a similar price performance curve for the forseeable future, these things should be available and affordable in the mass market in the next decade or so.
We then reach the point where conventional storage is able to be completely absurd. We currently have over 100 times the capacity we had available about ten years ago for about the same price. Let's face it, it is hard to figure out what you would use a forty terabyte drive for, but I'm sure an OS and an animation based office suite will be developed by somebody that will make a valient stab at it.
so by that time SSDs will be far more affordable as well, and there will be a shift to this technology because of the cost. Note that a similar technology is seen in PDAs. Right now PDA's have the capacity and power of the old 486 machines. Imagine when they have the capacity of the current generation of desktops.
Desk Top machines will have a similar boost in power, but may go to SSD technology, simply because of the performance boost. and most people are not editing movies, etc at home.
One use of the incredible space that comes to mind is the software used to do the battle scenes in the Lord of the Rings. Imagine when this will become a desktop product. You could then create a movie usually methods similar to making a midi file. Events specified invoking effects generated by the computer, printed to video.
"It is a greater offense to steal men's labor, than their clothes"
I think I will keep the HDD merely for the fact they don't cost as much and I don't lose my data if I turn off my hard drive.
The current basic and EXTREMELY old computer architecture (which is CPU, memory, storage device, and IO devices) already solves this !
You store everything you need on the STORAGE DEVICE, and access stuff by copying it to MEMORY. If you what you need to access is big (like a database) - add more memory.
Actually, the only difference between MEMORY and STORAGE DEVICE is speed. If they were the same speed, we wouldn't have needed one of them. Shoving the memory away from the processor is like saying 'let's put a hard drive instead of memory - that way we'll have hundreds of GBs of memory !'.
To be fair, I'll add that it might help on 2 occasions:
1. Systems which are memory-limited - like my PC which is limited to 4GB. But I'm guessing that computer manufacturers will continue to expand this as needed (both for PCs and servers).
2. Loading-up such a system - reading those GBs from an HDD to the memory will take longer than loading it from memory.
But other than that, I think that stuffing the memory in the storage device and saying that you have a fast storage device might be true, but it's plain stupid !
"disk" is shorthand for diskette damnit! :)
Only floppies are "disks".
Wes - Crazy like a fox.
My personal data?
Let's list some common consumer appliances that offload data to the home computer:
mp3: 1MB/min of audio
video from digital video cameras: Lots of GB here
digital photos: getting bigger all the time.
DIVX video: almost a gig per movie.
Video Game: 2 gigs of space, easy.
PVR: the more space the merrier.
So seriously, what are you smoking?
In the old days, there were all kinds of ide incompatabilities.. some drives just would not work with other drives in master/slave configurations. Bios issues, etcetera.
Nowadays, any modern computer (by modern, I mean from the last 4 years or so) can use any hard drive out today, with no problems at all.
My mom eats 30 gigs for breakfast.
I always wondered if this would be a good idea once economies of scale kicked in and design knowhow was put toward it
Basically, you have your normal 120 GB disk for your files. But the swap file exists on a different GB hard drive thats only 1% the size of the usual hard drive, specifically manufactured for high speed and a lot of cache. This hard drive holds the swap file, which probably accounts for the majority of hard drive accesses. It wouldn't cost $5000 like an SSD would, but maybe 30-50 bucks once a few hardware generations went by.
Maybe it could be an integrated RAID of four small drives (I always forget which RAID configs optimize for speed).
Hey, I'm just your average shit and piss factory.
For the masses, the next release of Windows should feature built-in Mt. Rainier support and I believe Linux has had its act together on this one for a while.
There are no karma whores, only moderation johns
I don't know, Executor looked pretty damned expensive.
when they could spend less money and buy dram instead - which shuld be faster.
Which would involve running most apps in slow emulation because if I already have several GB of DRAM, the most popular processor architecture in which proprietary software is published can't handle much more.
Will I retire or break 10K?
What if someone started making SSDs for the consumer market, though? How cheap could they be?
Produced at modest volumes in the USA (not made by the boat-load in China), we've been looking at somewhere in the $250 to $300 (usd) range for the bare board with 16 or 20 DIMM sockets, IDE interface, and power management circuitry with aux power inputs.
The unit is planned to fit into the form factor of a cdrom drive, which allows just enough room for 20 sockets and a couple inches to pack in all the circuitry, IDE and power connectors. There just isn't room for a battery, so the plan is to have 2 or 3 "aux power" connectors that accept 9 to 12 volts. We'd make a battery pack that fits into a 5 or 3 inch drive bay and recharges itself from PC power, so you could connect 1, 2, or maybe even 3 battery packs, or maybe a battery pack and 12 volts from some external source like a "wall-wart" power adaptor plugged into a cheap UPS, or maybe something a bit more "reliable". I'm not sure what the battery pack will cost, but it's hard to imagine it'll be over $50-60 even if we splurge a bit for a fancy microcontroller-based rapid charger and advanced battery monitor.
Today, 512 meg DIMMs are the most affordable, and today's pricewatch says about $40 for PC100-SDRAM and $46 for PC2100-DDR. Prices fluctuate quite a bit... a few months ago the 512 meg PC100-SDRAM was $30. But assuming you pay $40 each for 20, plus $280 for the bare drive and $60 for a battery pack, that puts you at $1140 for a 10 gig ultra-ultra-fast drive. Ouch. Even if the prices drop back to $30, which puts you under four digits, it's still quite expensive.
But not as expensive as the article claims.
Anyway, at this point the project is pure vapor. The earliest you might see it would be about one year from now, but 18 months is more likely. Even though DDR is more expensive today, the design will almost certainly use DDR because it is expected to become cheaper and remain more easily available for the years to come. It's also quite likely I'll do serial ATA only, as S-ATA is going to become the mainstream down the road, and it's already gaining acceptance now. My hope is that 1 and 2 gig DIMMs will become more common and their price/byte will come in line with the 128/256/512M sizes.... 'cause there's no way we're going to get more than 20 DIMM sockets into the 5.25 inch drive bay form factor.
The project also has a number of technical challenges... including the difficulty of connecting that many unbuffered DIMMs (the design will need 4 or 5 separate memory channels and a lot of buffers & PLLs that there aren't really room for on the board).
Well, enough vapor for one day.
PJRC: Electronic Projects, 8051 Microcontroller Tools
I find it quite odd that the title of this is, 'Getting Rid of the Disks', considering that the article is about why it would be too expensive for a normal user to switch to SSDs.
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"In times of universal deceit, telling the truth becomes a revolutionary act."
-- George Orwell
Should use intelegent drive management.
Since solid state memory is cheaper now than it was, disk drives should use giant amounts of cashe... Perhaps 512MB... let the OS put the common stuff there.... that way boot time, and such could be quicker.
Kind of like auxilary ram. The OS can put stuff there based on what it thinks should be there... for example commonly used apps (in most cases a webbrowser and email client)..
Can also expand on the idea and use solid state as a form of backup, since it's so reliable. Have the system automatically compress data on the drive from specified directorys, and backup to solid state memory.
There are so many potential uses. We rely on hard drives to much.
That said, I'm looking at a DVD-R drive. While the rewritable DVD's don't work everywhere, the non-rewritables work almost anywhere, and DVD-R discs can be as cheap as $0.70 each (DVD+R's are several times more expensive). This falls well below the $1/Gig for HDD storage, and they are very conveniently removable.
Hardware, software, and blinking lights!
Option three : buy a spare computer with a TON of hard drive space to dedicate as 'offline' storage. It isn't particularly expensive anymore (although no where near as cheap as tape) but it doesn't take a week to do a system backup either. Doesn't have to be a fast state of the art computer, just have a lot of drive space.
: ...
Do a system image once a month of your entire OS, apps, etc... stored to that machine, then just back up your data once a week. If it takes you a week to back up a system now you are only backing it up once a week anyways.
If you were creative you could probably come up with a 1TB server (IDE drives) and a GigE network card for under $1,500.
Notes on your post
Under option 1), if you do RAID5 you always lose the capacity of one disk. If you want to minimize costs use bigger drive sets (ie. in a 6 drive set you lose 17% (one drive), but in two 3 drive sets you lose 33% (two drives.) Granted it is a little difficult to do a 6 drive set using IDE, and SCSI drives are still a little pricey when they get big
Under option 2), if you store the offline drives in a quiet, cool, dry, clean place (those mylar bags they came in when you bought them, for example) I don't think you are going to experience hard drives demagnetizing themselves much.
Glonoinha the MebiByte Slayer
The guy lays out this elaborate scheme for having 20GB of DRAM backed by a 20GB disk.
Why not just use a few gigs for a great big disk cache?
Oh, wait, because that's exactly what modern operating systems do, so his article is completely pointless. Disk not fast enough? Add more cache...
Now, why does it *still* suck? The problem is simple: the filesystem. We're all stuck with a great big 50's era hierarchical DBMS running on our machines... think of all the crap you have to go through just to get at your files, and then you have to hope the filesystem isn't going to slow you down too much by letting your data get fragmented.
Does the "file and folder" metaphor not suit you? Tough. Don't like a long stream of bits? Code around it. Want transactions in your system? Do them yourself, filesystems are relics from the 50's when transactions were way too heavy.
And *forget* about application-independence. Once you've written a Word document out, it's only useful for a wordprocessor. No logical schema, no integrity constraints, forget *all* of that.
And definitely forget about a single-level store. Your program is going to have to spend its life shuttling crap between Storage and Core... even though most of your Storage is in Core and most of your Core is in Storage.
That's why the first thing a serious DBMS does is ditch the filesystem. We ought to treat the OS as a serious DBMS, too.
The basic principle is more or less the same for both technologies, but since FRAM is made on an IC, it doesn't need millions of hand-wirings to put together. Fast, small, cheap, mass-producable core memory. I like it.
Hardware, software, and blinking lights!
This idea has been used for decades. The C64 had ramdrives of up to 8MBs available that did just this, even though the base system could not have more than 64K of system RAM onboard.
Hardware, software, and blinking lights!
get a nice 64-bit system (hello, athlon64),
slap 8 or so gigs of ram and a four-disk striped raid array on it.
half of the filesystem would use 2gb on each disk as a database,
to be updated twice a day.
the other half would be on that ram, in the form of diffs on the hdds.
on top of this, you put a more intelligent system
to handle things like downloads (go direct to hdd)
or swap (never go to hdd).
this would be interesting for test machines,
which would never sync ram to hdd,
or multi-user full-access boxes,
which could have a distinct bank of ram for each concurrent user.
all we need is for somebody to design the filesystem,
which should probably look like cvs and ext3;
think of it as a journalled ramdisk filesystem
with the journal kept on hdd.
Use my userscript to add story images to Slashdot. There's no going back.
Ouch - come on man quit teasing us. This is EXACTLY what we want, although I would suggest supporting ATA-133 on down. The reason people want to add a SSD is to make an existing computer a LOT faster ... if they have to buy a new computer (that has SATA) simply to use your SSD then the price isn't just the price of your hardware, it is the price of your hardware PLUS the price of a new computer. A hundred million PCs are getting sold this year without SATA support and that means there are a hundred million computers (customers) out there you are insuring you can't sell to if you only support SATA.
...
Secondly, rather than planning your first release to be the superduper box in 18 months, how about a 'pretty good' box that supports regular IDE (ATA-100 on down) in 6 months, sell some to generate some cash flow, learn from the feedback of your early adopters, adapt the engineering changes into your superduper box v2 that is still getting released in 18 months.
Maybe the first generation skips SATA, no battery backup, uses PC100 SDRAM, make it full height (two 5.25" bays) instead of half height if you need the room, perhaps see if a SCSI interface might get you out the door sooner (much less intelligence on the drive in a SCSI implementation)
Lets face it, the first generation of anything usually has pain - so plan on your uber release being v2 in 18 months and release (sell) your first generation in 6 months.
Glonoinha the MebiByte Slayer
I think that Quietti was going by the "would you cry if you lost that standard." As such, stuff you created yourself would most likely fit in that category, while huge piles of mp3's, etc would not So, you would have (at least) 2 drives. Maybe more. A bulletproof 2-4GB drive for "cry if I lot that stuff" and other, larger drives for the big stuff. Digital pictures, home movies, etc. definately fit into the veil of tears category, but large cap. HDD's don't have the reliabilty necessary for these. So, we burn CD's and DVD's. This is all theoretical, my only "backup" is that I have three computers that I roughly sync my important files between... Tears could be in my future.
Does anybody know how big disk tracks are these days? If 2MB was enough on a 20GB disk, does a 200GB disk need 20GB, because the tracks are 10 times as large, or does the disk have 10 times as many tracks of the same size, or somewhere in between? The price of memory hasn't come down as fast as the price of disks, but it has come down a lot, and 10MB of RAM costs about $1 - even though the price of disks is really competitive, drives might as well have as much as makes sense for current geometries and speeds. The sizes are still likely to be on the order of 10MB, not 256MB, and since there's got to be _some_ chip there, it's cheaper as well as more reliable to just make the chip big enough rather than adding sockets for plug-ins.
Large quantities of write-cache on a disk drive are bad, though, because they're not backed up by battery - the system needs to know that when it's written something to disk, it's really written in some form that can be read back later. Read cache is harmless, because losing it just loses a bit of repeatable fetch work - you need enough to cache a couple of tracks of data, but more than that doesn't usually accomplish much, unless there's a big mismatch between your disk speeds and the bus that transmits to your system memory.
Caching cards are usually silly, unless they either provide battery backed-up RAM or are part of RAID controllers where they can help in the assembly/disassembly process. Their main purpose is to make up for limitations in operating system caching design (i.e. they help Windows a lot more than Unix) or making up for other hardware limitations (e.g. CPU RAM limitations, or bus speed differences, or letting you run server disks off the otherwise-unused AGP port instead of the PCI bus.) Their other main purpose is to take advantage of memory speed / price differences - disk caching works just fine with cheap PCI-100 memory, while system RAM needs to be the fastest Quadruple-Data-Rate Gigahertz-RAMBUS Quadruple-Price memory you can buy to keep the CPU running at maximum speed, so if you're buying large quantities of the stuff, it's sometimes worth spending an extra $50-100 for a card that can hold lots of cheap memory.
Battery-backed RAM cards are actively useful for applications that need secure writes, such as database commits or NFS writes. A decade or so ago, the Legato Prestoserve NFS accelerator cards had a meg of battery-backed RAM, which was enough to commit writes to while waiting for the disk drive to spin. This meant that you could respond to NFS requests in sub-millisecond time rather than waiting 10ms or more for a disk to seek and spin (seek time was still slower than rotational latency back then, plus your request might be queued with other disk requests), so you could handle one or two orders of magnitude more requests per second, and a megabyte was more than enough to buffer traffic from a 10mbps ethernet. Database transactions might be generated much faster than NFS requests, but it was still enough to handle caching for a lot of disk space.
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
[sarcasm]Oh, you mean those files that sent you to jail after the RIAA came knocking on your door?[/sarcasm]
No, seriously, I have a few people's own demos as mp3. For everything else, a nice CD collection and incoming Shoutcast streams via broadband give me all the music I need.
That's probably why I have an iMac. Without it, I wouldn't have seen the Enterprise series...
I use a scratch partition mounted via network to collect what mine spits and, after editing, the album/movie goes to CD.
That's probably why I refuse to use regular surface mail to send documents, nowadays; I scan everything and e-mail it as attachments, unless they absolutely insist that it won't do.
Clearing old mail off your $inbox would do you good.
Ever heard about the demo scene? I didn't think so.
More like, 2Gb drive and between 256Mb - 1Gb of RAM, on average. 2Gb is all the storage I need for the applications. Home directories are mounted from a fileserver, which has a 4.5 drive mounted as /home that is available thru Samba.
That would be pure waste.
I would probably end up like the other poster who replied to my post said: 40Gb drive of which only an 8Gb partition is used - either because the BIOS on some hardware (yep, I heard about "flashing the BIOS", but Compaq apparently has not) cannot handle more than a few gigs, or more often because the applications I use easily fit the 2Gb constraint of workstations and /home is mounted via Samba.
Software is not supposed to be about how to work around a useability issue. - Ken Barber
The operational costs of using that tape were generally higher than the disk drive - a good tape robot and automation software can reduce them, and to make up for the lack of random access on the tape, you need to make the tape from backup/mirror disk rather than from working disks (while queuing up journalling request for the drive you're making the tape from), but restoration was the hard part.
It's possible that tapes are still cheaper for offline archival backup - the weekly stuff you dump in the safe deposit box so you can defend yourself against that patent lawsuit three years from now, or get that copy of version 0.6.1.8 to support that customer who's got a problem with the embedded device he built last year that uses your code. I've never found tapes to be highly reliable; you certainly don't want to trust them for restoring last night's build when the developers scrambled things this morning, and one reason you can trust them for your weekly archives is that if you lose Week N-48, usually Week N-47 or N-49 will have a copy of what you need.
But you've also got to keep a spare tape drive in your archive vault, and a spare copy of your backup software, because it's likely that any Really Bad Event that wipes out your onsite disk storage will also trash your tape drive, and tape drive formats seem to change at least annually, or at least the interfaces and backup software do, and the Non-Random-Access performance of tape and the popularity of compression means it's highly likely that the data format on the tape is much different than a disk file system; you can't simply find an old ATA controller or USB1.0 bus and expect to plug the thing in and read it. You don't necessarily have to store a backup tape robot - a single drive of the appropriate type is probably adequate - but you at least need the drive and all the software.
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
" The basic principle is more or less the same for both technologies, but since FRAM is made on an IC, it doesn't need millions of hand-wirings to put together. Fast, small, cheap, mass-producable core memory. I like it."
Now wouldn't that be a hoot. Computing come full circle. Throw in the push for moving most work back to a centralized location and we're there. I wonder if tubes are next? With IBM's millipede technology the punch card may make a comeback.
The only component making any noise in my computer right now is the HDD...
Also, you always need backups in any professional environment - RAID protects you against disk failures, but it doesn't protect you against accidentally deleting an important file, or editing the wrong file, or crackers or viruses infecting your machines, or the RAID controller freaking and scrambling your data. Sometimes you can get by with journaling file systems on your RAID.
You can use 1+1 disk mirroring instead of RAID 5 - it has the advantage that to do backups, you disable one disk (if your controller's bright enough) or shut down, pop out the drawer with one drive, replace it with a blank drive, and rebuild the mirror. If you underestimated your storage requirements, add another pair of disks (which will usually be bigger than the previous pair, at least if your underestimation was about growth speed rather than initial needs.)
Disks and tapes can both demagnetize or otherwise have Bad Things happen to them. They also get Format Rot, and Operating System Rot, and Application Rot, and other problems that are much harder to fix than magnetic bit rot. If you've got data that's critical for long-term storage, you need to preserve at least some of it by copying it onto newer devices. For example, copy the data from last year's monthly backup disks to new disks this year - if you're lucky, you'll need half or a quarter as many disks. And if the trends in disk drive price-performance improvement slow down from the radical increases of recent years, then it'll be cost-effective to reuse the old backup disks for new backups.
In a home environment, this is usually all less critical - over the last couple of years, I've found that disk drive prices keep coming down rapidly, so when I added the 20GB drive, I copied all my user files from the 6GB drive to it, and when I added the 120GB drive and took out the 6GB drive, I copied the whole 20GB drive into a partition on the 120.
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
IBM calls it a "single-level store". It's a pretty cool idea, but it has hardly revolutionized the industry.
The special cases are things like /tmp, which look like disk drives but mostly contain files that are created, used, and destroyed, and never really need to be saved on disk if there's enough cache space to keep them. The tmpfs file system type was designed to optimise these - it stores files in RAM and uses the virtual memory mechanisms to handle its data rather than a separate disk partition, and can really speed up applications like compiles because there's no need to wait for disk latencies or to even bother the disk bus with writes in most cases.
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
Also, you'll need to manage cooling and airflow.
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
Nowadays, not only do you pay a special tax on tapes and blank CDs, you also pay one on hard-disks purchased as separate parts, on the assumption that any storage media will be used to make copies of someone's copyrighted material. Adding insult to injury, after you have indeed ripped your legally purchased CDs, as suspected by that taxation scheme, you still get arrested for having had mp3s on your hard-disk, without having separately licensed them.
Software is not supposed to be about how to work around a useability issue. - Ken Barber
I wrote assembly code for 68000 and 6805 decades ago. I knew it was time to move on when I started dreaming in assembly and machine code.
The RS-232 chip interrupt bit flips and I wake up.
With any type of real market, these prices should come down very nicely.
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Add two Gigs of RAM to your mobo and run ramdrive software
Ever try to boot from RAM after the power was off overnight?
Somehow I still see a rotating media device as the boot device.
The truth shall set you free!
No, they are not, because you can use them all in parallel. That means, 50 parallel seeks, 50 parallel transfers, etc. Latency remains as for a single drive, but lots of other things are really fast.
If you read the papers at that site, the empirical conclusion is that the gain of caching large files is outweighed by the cache overhead. Always caching small files has two advantages: 1) you can now access any file (on disk or in memory) with a simple one-level pointer indirection, since you always know small files are in memory and large files are on disk, and have something equivalent to the standard inode table holding both; and 2) you now know every file on disk is "big" (for some value of big) and can optimize accordingly, in the process greatly simplifying your filesystem code (currently filled with lots of hacks for optimizing small-file accesses); an obvious win here is using large cluster sizes (say, 512K instead of 1K).
10 PRINT CHR$(205.5+RND(1)); : GOTO 10
Okay.. so it's too expensive for PCs, and it has a niche market in large dataset systems of antiquity.
The main use he describes on those older systems is as a substitute for installable RAM. So my question is this: If all your putting on this SSD is a swap file, why on Earth do you care if the media is erased between reboots?
Just use standard, PC66 DRAMs for the unit.
Article X: The powers not delegated... by the Constitution...are reserved...to the people
I have on my desk a recent magazine that discusses putting a swapfile on compact flash for the linux-based Zaurus (the pivoting clamshell one not available in U.S. yet, see sharp.co.jp).
The Zaurus has I believe 96MB of RAM, of which only 32MB are for the user (the rest is for decompressed OS image). Of course you could also fit an IBM HD on PCMCIA into it as well.
Well, CompactFlash is up to 6GB now, just give them a few years to get affordable at that size.
IDE will probably not be THAT fast, maybe you need a expensive SCSI card.
The BIOS could
(1) Set aside a certain section of RAM and offer it as a drive. Well ok so this could be speeded up by the chipset (seems both north and south bridges involved, so SiS can work this out well).
(2) The BIOS can map a specified portion of the RAM to a DOS-based RAMDISK, and copy windows and Program Files to it. This should be nice for Windows 9x, but the first option should apply well to all OSes.
Will work well with the present allowance of 4GB for a 32bit based system, use 256MB for RAM, the rest, as a temp storage.
"Give orange me give eat orange me eat orange give me eat orange give me you." -Nim Chimpsky
There is no reason to complain about the volitility of SSD drives! The way I see it, just design one with a backup battery that would last at least a day or two, then put the thing in a RAID array with a standard hdd. (I forget which number the mirroring one is) Would that not give you the speed of the ram and the non-volitile storage of the hdd? Personally, I would want something like this to load my OS on it for extremely fast boots. Even if I couldn't do that, I would still want it for loading demanding games into it for quick loading.
I remember reading a few years ago about how some people who had 256mb or 512mb ram was making a ramdrive and copying the quake3 demo into it. By doing that they were able to connect to a server extremely fast. Also, when the level changed they were the first ones in it.
One other thing, I don't think compact flash would make a good SSD.. everytime I've had a chance to use it, it seemed like it's as slow as any other hard drive. You'll have to look around for benchmarks and figure out for yourself though.
If you were creative you could probably come up with a 1TB server (IDE drives) and a GigE network card for under $1,500."
First, everyone on here has already said HDs are under $1/gig... make that way under ($94 shipped for 120gig), so less than $800 for the hard drives. Unless the "not state-of-the-art PC" + Gb card cost more than $200 (you can buy a freakin' 1.1ghz PC from Wal-mart for $200 so I'm sure you can do better) a 1TB server could be built for closer to $1000.
Also, if we go with the "not state-of-the-art PC" (I'm thinking 200-500mhz) is it really going to need a Gb card? I doubt it could write to the hard drives that fast (max speed of 120mB/s), a much cheaper 100mbps (max speed of 12mB/s) card and hub (a Gb hub is a lot of $$$$$ compared to 100mbps) would probably suffice, transferring 1 gB every 83 seconds is a pretty decent backup speed (43gigs/hr).
my karma will be here long after I'm gone
The other non-volatile memory. Bid for some on eBay today!
That said, a quick look at the current prices quickly confirms what you say... the two are about parity price-wise. Looks like it'll be a DVD+R drive after all (just about to run out the door and get it :P)
Hardware, software, and blinking lights!