Slashdot Mirror
Linux On Solid State Disk
Blah writes: "A while back Slashdot made reference to The Platypus Solid State Disk. The boys down at LinuxWorld.com.au have scored themselves one and given it a look over. The article has some pictures showing just how much SDRAM this thing has on it, as well as graphs which compare its IO and transfer rate performance against that of standard SCSI disk."
Yes, you am. Swap does not need backup power when the box dies so either use it as RAM or as a disk. Swap is a hack to work around the memory overcommit of the UNIX architecture (and other VM architectures)
- A.P.
--
* CmdrTaco is an idiot.
"Remember when the U.S. had a drug problem, and then we declared a War On Drugs, and now you can't buy drugs anymore?"
I would do grevious bodily injury for one of these devices.
A high percentage of my working day is spent waiting for compiles, as even a single change to a file requires on the order of five minutes of compiling and linking. A lot of that is file read/write time. If I could write it to memory-speed output rather than disk, I would be a happy man. According to the task manager, I'm not hitting virtual memory most of the time, but that hard drive sure is cranking.
Heck, we should probably pass around a hat and get one for Alan and for Linus...
Ooh, a sarcasm detector. Oh, that's a real useful invention.
Uh ? Put more RAM. Put even more RAM. And some extra RAM.
My machine is maxed out, unfortunately, at 256 MB. A solid state storage system could be added to an otherwise limited system. (Although at the typical prices they sell for, a new computer would be a cheaper option.)
Oh, I guess what your problem is.
Yeah, it's that the market for what I do isn't generally using Linux.
But yes, a gig of memory and a RAM drive would be a good approach.
Ooh, a sarcasm detector. Oh, that's a real useful invention.
There are applications out there where $60K is a small price to pay to increase performance rather a lot, and $60K starts looking small when you start pricing Sun E10000 servers and such.
The big value to SSD comes in when you've got one of those situations of heavy database updates where eliminating latency time is a big win. If throwing on a $60K SSD allows downgrading from a $1.5M server to a $1.1M server, that was evidently a very good buy...
A CF memory card system that doesn't allow you to hit it hard with vast numbers of updates just doesn't compare. And it's still hardly cheap; there aren't $60K units, but there aren't 8GB CF memory cards, either...
If you're not part of the solution, you're part of the precipitate.
Spend $8 grand on a decent RAID array, and see how the numbers stack up. They compared the thing to a single U2 drive! For $8K, I can get 2 RAID card w/ battery backup and 32 MB Cache (Ultra160 Mylex Cards for $500-700 each), 6 faster drives (10K RPM Ultra160 9.1 GB for $175 each), a data Silo SCSI box, run a mirror set between the 2 Striped RAID volumes (1 connected each to a card), and an extra UPS each for my server and the RAID boxen ($1000). Then see how the speed compares! Oh darn, I still saved some money...
We just got an SSD for our Sun mailserver. The OS won't go on the disk, though, we'll either use it for the pop lock files or for a mailqueue - either way we expect the load on the machine to fall dramatically.
Why is this better than putting 4GB straight into the server? SQL can be made to allocate and keep it all... I don't see the point.
"don't fall into the fallacy of believing that Perl can solve social problems. Maybe Perl 6 can, but that's a ways off"
get a nice UPS and then you are set
Its spelt "L-I-N-U-X", but pronunced as "Free Beer"
You would be foolish to use an external, lower bandwidth, more expensive interface that had to go through a swapping algorithm just to add more memory. It would make a lot more sense to just spend the 15 grand on big-ass DIMMs and a motherboard that can take them...
:)
But then again, it prolly would be good for swap, albeit a wasteful kind of good.
Heh. I've got one of those early production run SB16s. Big thing with an onboard IDE interface. Of course, I don't actually use it, but it is nice to have around.
Similar pieces of hardware, in terms of size and ugliness, are some of the early graphics accelerators (especially some of the Macintosh ones which used all these little ZIP memory chips), or the original Amiga Video Toaster (now there was a big card).
Is Samba a big enough project for you?
I don't think he's talking about systems actually required for flying the plane - things such as targeting systems (where information on which locations are planned targets could be valuable to the enemy) or map data (which would tell the enemy how much of their defense system has been located) would be more likely candidates for such treatment.
Then again, it could just be that the Air Force doesn't like sharing its sooper-sekret pr0n files with anybody else.
Or how about the fact that three of you just consecutively mispelled "grammar?"
;) Oh! Shood I have sed "mispelt?"
SlashSigTheorem: Humorous, Political, Critical, Constructive- If you have a
look why oh why dont these have standard interfaces ?
why arnt they arnt they useing memory interfaces ?
if they used memory interfaces then they could use JFFS or RAMFS
whats the advantage ?
BTW if you trust the newly dubbed IA32 to your mission critical system then you are a fool in my eyes sorry but its true SPARC/SH/ARM are the way to go because of debug in silicon (-;
regards
john jones
That's a really really expensive hour of battery time. You coulda just bought fifteen extra batteries.
--
There are no trails. There are no trees out here.
How would this stack up to the solid-state drives available here ? They use a standard SCSI interface, shouldn't require special drivers, and don't use up a slot.
Nice performance, though.
Yeah, 'cause those people in the non-English-speaking countries aren't very intelligent at all, are they? Look at the Japanese! Idiots - the whole lot of 'em!
I mean, think about it...ram is not _that_ pricey. There must be a lot of research dollars to compensate for. You can get 512megs of pc133 for ~US$200, so why does it cost outrageous sums for the drives? It's not like scsi itself can make up all that cost. Heck, even old edo would give faster performance than our current drives. Slap a bunch of that in a box, put on a scsi controller and I think a lot of people woud be happy. Or even better, put it in a pci card. The main problem with the pci card being physical space...
-- Who is the bigger fool? The fool or the fool who follows him? --
Wow, our user ID numbers are close together.
:)
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Check out my blackbox styles
If I remember correctly I told you to sign up on /. so you didn't post as an anonymous coward.
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Check out my blackbox styles
First, it has to be powered up to work. The external power supply is almost redundant. I won't be rebooting my production linux box more than once or twice a year, and even then, the reboots will be planned. I could easily back up the drive without the external power supply. If I were to suddenly lose power, it wouldn't matter anyways since the external power supply would most likely go down as well.
Second, for 8 gig models, having a separate PCI card holding the memory makes sense. But for less than 2 gigs, you will probably be better off just using a ramdisk. Not only will this allow you to have more control over the actual memory allocation, there shouldn't be any dramatic difference in performance. As I said before, a sudden loss of power for your server is just as likely to take out the power for the drive as well, so you're not in a much safer position the other way.
Just a few thoughts.
-Restil
restil@alignment.net
Play with my webcams and lights here
I don't see what the fuss is all about. I can put a couple of gigs of RAM in my main machine, bot up the OS, and load a gig or so RAM drive, and I've effectively got what everyone's talking about here, without any extra hardware (save the ram that is). What's the big deal? Am I just missing somehting? I'm really not trying to start a flame war here, I just don't get it...
LOAD "SIG",8,1
LOADING...
READY.
RUN
reincarnation of VESA
is this really true? can you provide a link? thanks
use LaTeX? want an online reference manager that
-- john
for the most part i would think the os should be caching frequently accessed files like web pages and scripts. the platapus would be better at preventing the /. effect if you accessed the memory as ram. it's probably all of the spawned httpd processes that kill the servers.
use LaTeX? want an online reference manager that
-- john
he VESA Local was hard to work with, and you only had one slot,
i built quit a few machines with more than one VLB slot, where did you get this from? they did make nice graphics cards though. there were also good controllers and scsi cards too.
use LaTeX? want an online reference manager that
-- john
http://slashdot.org/comments.pl?sid=01/02/09/12522 18&cid=10
15 grand is a hard bargain, but 50 nanoseconds? how many times a day is that? 3 zillion?
does it come in blonde?
Only then it was called a RamLink. Same concept, about the same hardware, only it was for a commodore 64. Brilliant idea really, just not viable until ram gets extremely cheap.
Wouldn't it have made more sense to test this against similarly priced storage systems? In the $5000 range you have fibre channel raid controllers with some storage. A good FC card will push around 200 MB/s. Why not have a measure of MB transferred per second per CPU percentage? Put that next to $ per MB storage and you get a real comparison.
This card is limited to 100 MB/s and is only 32-bit 33 Mhz so can only be grouped one per bus in order to maintain that speed. Meanwhile, most FC RAID cards are 64-bit 66 Mhz, run around 200 MB/s, support multiple cards before maxing out their target bus. For $5000, you are going to get much more storage than this thing and it will be faster. I just don't get it.
I have one technical issue with the article, too. It contains the following line: "Current PCI bus speeds are limited to 33MHz, however, 64 bit PCI bus systems are in development and have speeds of 66MHz." This isn't correct. Both 64-bit and 66Mhz PCI systems have been around for some time. I was at the Microsoft Plugfest for Windows 2000 and Millenium testing my 64-bit 66 Mhz fibre channel card in systems from various vendors. This was back in December of '99. Also, the signal rate and signal width are not automatically linked, although most 32-bit buses only support up to 33 Mhz and most 64-bit buses support up to 66 Mhz.
-- soldack
Actually the I/O bandwidth of an SSD is limited by
the fact that many of them have SCSI internally, and even if they have FC back ends you'll only get 35MB throughput, but latency is nice.
a slashdotted server would be probably dealing with a small enough amount of data that it would all be in host buffer cache.
--Britt
The US Air Force uses solid-state disks in at least some of its aircraft. They load the software right before takeoff. The idea is that, if the plan goes down or is captured, the pilot just has to power it down and all the software is lost, and then the plane is useless.
- - - - -
Napster-to-go says "Fill and refill your compatible MP3 player", which is a lie. It's not MP3. It's WMA with DRM.
Some info about VLB.
VLB (VESA Local Bus) is used mostly on 486 computers. It uses a direct connection to the CPU (no bridges like modern PCI computers or older ISA buses). It was designed to be a cheap solution more than anything else, by not requiring a fancy bridge like EISA did.
VLB has the following characteristics:
Bus speed is same as Motherboard bus speed, typcially 33mhz.
When operated at 33mhz, a maximum of 3 cards can be attached.
At 40 mhz, only 2 cards.
At 50 mhz, only 1 card.
This limitiation is caused by the amount of current the CPU could send over the IO lines to the VLB cards. Since there is no bridge between the VLB bus and the CPU, the signal strength from the CPU can not be amplified to service more cards.
Cards for VLB include network cards, video cards and disk controllers (SCSI and EIDE).
Let's say you have a web server with 1gb of memory and your whole content uses 100mb. How would you set your server up to run only in memory? You would still have a hard drive also.
I know you need to setup a RAM disk and copy the data over each time the computer boots... but what exactly would need to be copied over to the ram disk to make is speediest. Everything? ("/usr" "/" "/var") RedHat's distro is huge you don't to copy it all over into memory. What about Apache bin? a database driven site with MySQL?
Would just copying the web server content each time it loads and serving off that speed it up significantly?
Would it be worth it? Or would using an Apache cache module work just as well?
PC133 => 133MHZ * 64bits (8 bytes) = 1GBps.
PC66 => 528MBps
Difference in price for standard SDRAM is neglegable. (pricewatch has 512Meg sticks for under $200, meaning the $5,000 price-tag is most likely NOT mainly comprised of DRAM)
But here's what happens when you underclock: The pipeline get's slowed so your latency increases.
Random read access should take a hit of about 5 clock ticks per access (actually more because of intermediate custom hardware). So random single byte reads suddenly are slowed to 105MBps, but since we were only interested in a word, we only got 13Mega accesses / second. By staying at PC133, you effectively double that minimum rate.
Now the difference in price from CAS3 to CAS2 PC133 is significant, I'll grant you.. Probably not worth the premium.
I admit that most if not all "virtual disk accesses" are going to be in 512B blocks, which comes out to 16 indepedant cache-line-bursts (8B/cycle * 4 cycles), and should thus take overhead(approx 5 cycles) + 4 cycles * 16, or under 70 clock ticks for a full sector read. That's about 1.9Million sectors per second theoretical peek (not bad). At that point, we have to contend with main-memory BW saturation and CPU over-head for disk-drivers. I believe that depending on how intelligent the drivers are, the PCI bus isn't the real bottle-neck for over-all system performance on such a ram-drive.
I am curious about the prospects of converting this PCI card into a UATA-100 hard virtual drive. You'd have higher peek bandwith, PLUS you'd be able to perfectly emulate a hard drive.. However, there is probably an advatage to putting memory on the PCI bus - namely that the OS drivers could directly access the media in little segments based on the actually requested data instead of duplicating disk-block-buffers in main memory, just to ultimately copy out to user-space.
-Michael
-Michael
VLB is not limited to one slot. I have three in my server (486-100), one for graphics, one for IDE, and one for network.
Not to mention the $5,000 price tag, if you're in a position where you have to worry about things being plugged and unplugged.
But damn, it sure does look cool. I'd almost want to buy one just to stare at it. It's the first piece of hardware I've seen in a while that hearkens back to the era of the bulkiest, most awesome piece of hardware ever, the ISA Sound Blaster 16. Those things were beasts.
Of course, I guess these things need room for all that RAM..
...In which case you really gotta re-ask why this particular piece of hardware is such a boon.
Microsoft product suspected.
Linux zealot team scrambled to liquidate target.
ETA 6 minutes.
I think the real question on everyone's minds as we examine this product is obvious. Can a boost in I/O even as massive as promised by this piece of hardware actually save a poor, unwary server from the Slashdot Effect? Now *there's* a benchmark I'd like to see.
Insightful??? excuuuuuuuuuuuuuuuuuuuuuse me?
Why didn't they make this an AGP card? It's a dedicated port designed for fast I/O. I know that AGP is the reincarnation of VESA, but does anyone know any reason why this wouldn't work?
The device is a fine thing if you can fit your data in it but what if you want to combine multiple cards? At $8K a pop they're hardly cheap. Through together a few drives and you can match the read throughput of the SSD (I used to have [last job] a dual-proc Linux box with 9x 36GB IBM drives using s/w RAID-5 [big blocks with ext2], reads at 60+MB/s [PCI limited?], writes at 30MB/s, according to bonnie :)
Sort of. Its a SSD, but it connects to the SCSI2 interface on the Proliant 8500. 4GB of storage, but it isnt seen as a hard drive. What it does is as you boot and the OS loads it automatically starts caching everything to the SSD, when it gets full the controller uses the SSD as much as possible, while relying on the regular scsi drives when the info wasnt located in the SSD. Made SQL server scream though, real nice. 35,000$ though, so I doubt we will be getting alot of em.
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Looking for hardware (Currently need: Large Etch-a-Sketch) Have one? See my journal!
I could be wrong on this, or CompactFlash may not be flash. Last I read somewhere that Flash memories is SLOW and have a relatively SHORT lifetime. Hm...not a good candidate for mass solid state storages at all?
How about a customizable killfile?
Or a customizable regex link matcher to kill links like the goatse ones only retards post?
Thanks.
> Data is kept intact when you power down your system by powering the QikDRIVE card with an external power supply.
OK. I hope you've got a UPS on that. I'd hate to see someone get everything configured in an operating system stored in one of these and then see the power go out.
Looks like they got a new Domain, www.linuxroms.com
iRepairIT - iPhone, Mac, & PC Repair
You'll have to excuse the troll / off topic message, but I followed the link and got an error message stating "Unable to Connect to SQL Server!"
Let's just hope that this is a generic "Unable to connect to a database server that uses SQL as its query language" as opposed to "Unable to connect to that one database that will only run on that one operating system that crashes way too often (as supported by this error message)".
Actually, I'm pretty open minded. If there's some reason they need SQL Server, more power to them for working to integrate with a quick and dirty OS.
Isn't that pretty dangerous, though. I'm sure that the engineers have thought of lots of horrible scenarios and worked through them. But, what if something happens to the power in the aircraft (hit by lightning, say) and that device looses power. The plane's system can't reboot then? The pilot is dead in the air?
I suppose that the pilot just ejects and the plane is totalled on the account of a faulty power supply. Sounds about right. 1 billion dollar plane lost to a couple thousand dollar part.
...I've been running Linux on SS disks for some time now. I use the BiTmicro E-Disk line.
[Got Hosting?]
In fact, why are any SSD devices so expensive?
Especially this one, that uses normal SDRAM. What in that card costs so much? It's certainly not the RAM. Can the chipset that manages the writing to and from the RAM really cost so much? Shouldn't it be possible to hack something like this together for a couple hundred bucks, much like people do with MP3 players now?
The Playtpus SSD doesn't do much for me. My goal would be to speed system recovery in the case of someone kicking out the plug without going to the extremes of the EROS project, and without doing the damage to file system performance needed for conventional journaling file systems.
Sanity is a sandbox. I prefer the swings.
that they're talking about military things, do you? "I've got the ball" indeed....;-)
Vintage computer games and RPG books available. Email me if you're interested.
That link again :-): www.dansdata.com/cfide.htm.
I thought that Slashdot was supposed to be all about new info. I mean, solid state drives are nothing new. Is the only reason this was accepted to be posted because this article had the word "Linux" in it?????? Lame.
--JLockard - "Some mornings, it's just not worth chewing through the leather straps." - Emo Phillips
... But did you ever try and BUY one of those quantum drives? Fat chance. I gave up after being told lead times were over 2 months, and no guarentees. I went to soliddata.com. It's a neat box that has "bigass" ram cards, an internal UPS, and a harddrive to store the contents of RAM. Standard really-fast SCSI interface (availble in a variety of speeds.) Totally plug and play, looks like a normal harddrive. Quantum may talk, but they can't deliver.
Quantum has had solid state drives for almost 4 years now. They pioneered the field and their scsi SSD's blow the doors off anything out there. And with an added benefit, it's native scsi, no special drivers needed, access times in the 50ns range, as opposed to the standard 5-7ms for even Cheetah drives.
"See, we plan ahead! That way, we never have to do anything now."
Although this is quite funny, after Doug Miller's recent comments would the pot please refrain from insulting the kettle.
yaknow, I've had one of these devices for about 1.5 years now. I've posted about it, did *all* the US beta testing under NT/2k/FreeBSD/Solaris, and nobody noticed. Now we see this? What happened to cutting edge?
-JPJ
Feh.
Why use a swap partition at all if you can just buy more memory? Isn't that the same as buying this?
Might be good for people that have all their slots filled. All in all, sounds like a very cool product.
This isn't really a new idea, because I've had linux running on a 16Mb solid state Sandisk for a couple of months now... makes a great item to have in a router. The disk has an IDE interface and performs very well.
Skiers and Riders -- http://www.snowjournal.com
Although Australia is large by area, the population is less than half that of the UK.
This could be made cheaper through MB integration.
I think all you would need to do is have battery backup of one dimm slot. A feature, that without including the battery, would add less than $1 to a MB.
Basically the MB already has the memory controller and DIMM slot. BIOS programs are probably unneeded (for linux anyway) since kernel startup routines could just scan the ram.
If I had $15,000 and a good reason, I'd buy a Platypus in a heartbeat... What do you mean it's a harddrive? Whats a Harddrive?
Is there heaven? Is there Hell? Is that a Tuna Melt I smell?-Primus
What would happen If someone(me) held a contest with a $10,000 reward for Open source SCSI Ram Drive?
Specs(min):
SCSI1 Interface. May not excede Full height drive bay dimentions. Must accept one to eight 512MB DIMMs. Drive needs to be OS/BIOS transparent. Parts list, alternative IC list, Schemitics, any source code, PCB layout, and working prototype must be submited to judgeing body.
Cash will be held by Slashdot until winner is chosen by a pannel comprised inpart by Slashdot admins.
Just an (rough)Idea. The money's not the problem here.
Less than 1/3 the population of England. Easily less than 1/4 the population of the whole UK.
Just over 4 times the population of Nebraska, I think.
FatPhil
-- Real Men Don't Use Porn. -- Morality In Media Billboards
Also FatPhil on SoylentNews, id 863
More like 18 million. And, Vegemite aside, a fair bit of good stuff comes from Australia. They also have a tradition of exporting their best and brightest to work in other countries (funding for universities really sucks under the current Australian government---after living there for a few years, I just moved back because it's easier to pursue a career in the USA). If we could get figures for ex-pat Aussies working on projects I suspect that everyone would be quite impressed for what Australians do with only 18 million people.
We had one of these in the office, in company that
ceased to exist, they are interesting for limited
access terminals, and such. Hardware in diskless
slimlined cases is about year or two behind and
costs just as much. Great thing,though they have
'expected' diminshed breakdown rate, because of
absense of mechanical parts... that is expected.
Am I foolish to think that this would make a great swap partition?
Solid-State hard drives are so expensive because they use SRAM, not the DRAM you are referring to. SRAM, or Static RAM, is an entirely different memory technology from DRAM, or dynamic RAM. It's main selling point is that it is MUCH faster than DRAM. The problem with it is it is much less dense than DRAM and uses a lot more power. These things make it much more expensive than DRAM which is why you don't use it to expand the memory of a PC. In fact, SRAM is the kind of memory used in on-chip cache in microprocessors because of its extreme speed.
If you have battery backup for the solid state cache and if it's reasonably large, then you get pretty much the same effect as if you had a disk consisting of all RAM. Sun used to sell something like that for speeding up NFS called "PrestoServe".
Of course, Linux already has non-battery-backed-up RAM caches built in. The interesting thing is that even if the kernel crashes, you can usually recover the unwritten data from RAM and (after verifying something like a checksum) write it out to disk (this fails, of course, on platforms where the BIOS messes around with memory before the OS boots).
So, the best thing to do is probably to have battery backup for your RAM and processor and use an operating system that recovers information from RAM after a crash. That way, you can use normal RAM for caching, and if your machine crashes, you can recover quickly and with no or minimal loss of data.
I still use a SB16 as my main soundcard.
It sucks, and can barely play a mp3, but it works
All very well until some bright spark from A well known Consulting company decided to run a test by power cycling them many times consecutively. Of course, the battery went flat and the thing failed.
Apart from not being able to cope with a power cut every 15 minutes (maybe that means a problem in California), the things worked very well and were used to store critical files such as the database recovery journals. These things used to be the size of a minicomputer but quite happily fit with disk and integral battery into a 5.25" bay, probably even a 3.5" bay now.
See my journal, I write things there
The PCI bus was developed by Intel, lets see:
386sx
486sx
Pentium 60/66
Pentium II with 1/2 speed cache after the PPro
Limiting the Celeron to single CPU use
Limiting the PIV to single CPU use
ATX spec with no standards for accessory wiring
NLX spec with the connectors on the swappable card
Non-Busmaster USB controllers
The PCI bus sucks, try adding two Platypus cards into your machine, then your SCSI drives WILL be faster. The PCI bus does not handle device contention very well. You could say that it does not play or share well with others...
Your Average Joe
The closeness in name to a certain slang for a female body part will quickly overtake that name, especially if the Disk turns out to be flaky...
yah exactly.. i mean look at the Olympics they only have 19 million people (i just checked CIA world fact book =p) and they had so many medals i think top 5 or so in the world.
You do realize Australia has only 10 million people right? and what does english speaking have to do with anything?
but you can already get linux on an eprom chip
--
Adopt a penis cat today.
Of course these things are not new. But in a unattended system where you don't want ANY moving parts such as theme park rides, non-volatile ram drives are very important to have.
ipv6 is my vpn