Delaying Hard Drive Power Up? 53
Bamfarooni asks: "Does anyone know of a device that will delay
powering up your hard-drives (or other internal devices)? We're trying
to put a pile of IDE disks into a big disk server but the spin-up
power for these disks is about 3x the maximum operating current.
Rather than put in something really big like an 800W power supply, if
we could just put something in-line that delayed the power through
specific connectors for ~1 second, then we could mange with the
built-in power supplies we already have." An interesting thought,
but wouldn't the BIOS need to be aware of whatever delay is introduced?
Otherwise it may interpret the delay wrongly and think that the drives
on the IDE chain have timed out and are faulty.
Yes, Cliff, that's the problem (Score:2, Interesting)
There isn't any glory in such a hardware hack. There is just a lot of wasted time for a non-issue.
Re:Yes, Cliff, that's the problem (Score:1)
Besides, it's a startup problem, not a normal operation problem.
External (Score:2, Interesting)
Seems a lot safer and easier than trying to 'fool' them.
Re:External (Score:1)
Reboot once for bios (Score:1)
Another thing that worked with the same drive with an older mobo was that it would do all the memtests and check for floopies, and then search for them, and because it had like 30 seconds already to ready it's self, it was found. So if you can find a way of delaying through memory tests and floppy seeks that might work too.
Re:Reboot once for bios (Score:2)
Basically, on a cold boot, the system wouldn't start; you had to either disable the fast boot options in the BIOS or power up, wait 5 seconds and hit reset.
Re:Reboot once for bios (Score:2)
(this would probably work best for a non-booting drive)
Bite the bullet (Score:2, Interesting)
SCSI Can do this (Score:5, Informative)
I know you probably realize that SCSI does/can do this. But I also know that you're probably using IDE because SCSI drives of comparable size will be like twice the cost.
But, you might look into a hybrid solution by using SCSI-to-IDE converters. I'm not sure if the 'delay spinup' feature is dependent on the drive itself or just the SCSI Host Card, but if it's the SCSI card that does delayed spinup, you might be able to do this.
Something like this [cardaysupply.com] is what I'm thinking about. Of course, they charge $70 each adapter (which means per drive, too) -- though you may be able to get a better deal somewhere else.
Also, depending on OS, have you looked into a firewire solution? THey don't delay spinup, but you can use external power with them (via the drive or the hub/repeater).
Re:SCSI Can do this (Score:1)
Always use the right tool for the right job.
IMHO, a large scale IDE array == Dreamcast Beowolf Cluster
Re:SCSI Can do this (Score:2)
I have several older IBM SCSI drives (they're "only" 9.1 GB... geez...) that offer this option. It's a jumper that can be optionally set to command a delay of (x seconds) times the SCSI ID -- it has to be used in conjunction with the Auto-Start jumper.
The other option is from the host adapter: the 'unit start' command. Don't know if the SCSI-IDE adapters will do any good and heed this command...
Thinking about it, what with all the power saving and sleep modes that are supposed to be in HDs these days... you'd think you could just delay the start and get the BIOS to play along.
(Perhaps this is something the Linux BIOS Project can address?)
Re:SCSI Can do this (Score:2)
RE: wouldn't the BIOS need to be aware of whatever (Score:2, Informative)
Some motherboards settings (including a crappy Gateway i was messing with yesterday) have a "harddisk predelay" that you can adjust a time period before it polls for harddrives.
Adjusting that setting higher would address that.
just a thought (Score:1)
Also, you could turn on the computer with one HD, let it spin up, turn off momentarily, plug in second, let it spin up, turn off, plug in and turn on, ect ect....just make sure the drives don't have a chance to spin down completely, so you don't have to overcome the inertia of spinning up all those platters at once.
make sure the hard drives won't power down, if the computer came back from sleep mode, you'd probably blow the power supply after the third time ; )
Re:just a thought (Score:1)
A couple years ago (when I was a computershop tech)my JackAss manager was trying to "help" me build a PC faster so he could impress his customer. He took the liberty to plug a CD-RW in while I was installing some software.
Long-Story-Short... he blew up the CDRW (~$250) and powersupply (~$30) AND shocked the hell out of himself. I always liked the smell of burnt flesh and electricity in the air when I was a HW rat.
I don't hot plug IDE devices...
crappy hard drives that need to be hot-plugged(OT) (Score:1)
A difficult problem. (Score:1)
Let us say that this is for MANY machines, not just a workstation or server in a box. Let us further say that existing harddrives and powersupplies are already in inventory.
This could be a very real concern for many sorts of embedded/commercial applications.
Tossing in a little dongle with a cap and a transistor in-line might work, along with an extra soft-reset... but presumably any EE should be able to design something that can do it, for cheap.
Re:A difficult problem. (Score:2)
Go find an old AT Powersupply (Score:1)
Umm... (Score:4, Insightful)
Re:Umm... (Score:2)
why not use a (Score:3, Informative)
I forget what pins... but if you short two of the pins on the ATX motherboard connector, it powers up. In theory all you would need to do is make sure the drives all power up at roughly the SAME time. This could be easily accomplished with a few bits of wire and a doorbell
Some older bioses used to be able to init the hard drives at a timed delay. This was due to the fact that the hard drive wouldnt spin up fast enough to be recognized. This is no longer a problem, and has been omitted from all modern bioses.
Finally, the timed spinup idea isn't really a good idea. If several hard drives spin down, and then all resume at the same time, it would overload the power supply, causing damage to the PSU, and most likely other (expensive) components along with it.
Long and short: Use 2+ power supplies, attach both of them to a doorbell (or case button, but those are usually too small to attach two pieces of wire), and they will both power up synchronously.
840w peak power here (Score:3, Informative)
Doesn't exist? (Score:2)
Re:why not use a (Score:1)
Actually, I think you might have it backwards. The only BIOS I've seen with the option to delay the IDE scan is the one on the A-Bit KT7A I bought last month, and I've seen dozens of different PCs, from the 8086 on up, name-brand and no-name.
Melissa
Re:why not use a (Score:1)
Another solution (Score:2, Interesting)
Get a housing that will hold a bunch of two-circuit switches, one for every two drives. Get a bunch of those little hdd power cable ends (male and female) and some Y-cables, one for every two drives. Get the switches as well. Put the switches between the power supply and the drives. When you power up, throw a switch and let one pair spin up, repeat until done. Set a boot password on the BIOS. Don't enter it until all drives are spun up. If it does IDE detection before the passworf prompt, just do a soft reset.
This is really dumb. Get another power supply, or get one of those nifty DEC StorageWorks towers from your nearest data center that's chucking them out the window.
Use several power supplies ! (Score:2)
Re:Use several power supplies ! - (and a relay) (Score:1)
Time delay relays (Score:5, Informative)
They're pretty cheap ($20), and if you've got drives on a separate powersupply, hooking it up should be trivial.
BBK
Does this help? (Score:2)
BIOS issues (Score:1)
If you're running NT on those servers this might be a problem, but with linux it shouldn't be. Linux pretty much ignores the bios and does it's own hard drive searching. So that problem shouldn't be a problem at all.
As for the power issue, why not use one of those PCI-to-PCI extenders that will give you and extra case, and an extra power supply to put more drives in?
Re:BIOS issues (Score:2)
SCSI IDE for disk arrays. (Score:3, Informative)
Very handy for big arrays.
JWK
This *used* to work: (Score:1)
Note that you might be screwed if the drives decide to spin-down for powersave, and then spin-up simultaneously. Unless you hacked the IDE driver (noflushd on Linux could be modified for this but.. overloading the power supply like this is really asking for it. Bad things will happen.)
Of course, this is all back in the 486 age with 200MB IDE disks and BIOSes that didn't auto-probe the disks, blah blah blah.
Talk to a man named Farad about this (Score:2, Insightful)
Big Caps
Put one on each the +5 and +12 volt rails going to your drives. Be sure they're charged and isolated from leakage before powering up the system.
You could do a 2 stage power-up for your system. 1st stage uses the regular switch on your powersupply and does nothing but charge up the caps. Second stage is when you actually apply power to the motherboard and all your drives inside. This would require a separate switch that could turn on/off all the +-5 and +-12 volt legs necessary. A few relays or solid-state relays would do nicely, perhaps a plain triac or SCR on each would do, but you'd need to do some reasearch on those. I haven't messed with them for some time now.
After you hit the 2nd switch, the drives would get the current they need from both the caps and the regular [underpowered] supply.
Of course this is all a bit more work than just getting another small powersupply for $15 or so like everyone else is suggesting -- but you asked the question.
Re:Talk to a man named Farad about this (Score:1)
That means we need 0.570A * 5s = 2.85Columbs of Electrons. At 12V that would take a 2.85Q/12V = 238,000uF capacitor to hold that much charge. Of course you need to keep the voltage up so you need a much bigger capacitor, lets say by a factor of ten (I don't feel like doing the math to figure it out exactly based on the voltage on the cap) giving us a 2.375F capacitor. That would be physically huge, larger than the disk array. And you need another one for the 5V.
On the other hand some lead acid or NiCad batteries might work. Keep them float charged from the power supply and you would have plenty of startup current and pwoer backup. A car battery will provide over 100A for a short time. Only problem is getting the voltage right. 10 NiCad cells is about 12V and 4 NiCads is about 5V, but I think you would need something bigger than a D cell.
As stated above you would probably be best off with multiple power supplies.
Re:Talk to a man named Farad about this (Score:1)
Though I agree with you that perhaps some form of battery may be a better solution, I highly doubt that current drain would remain at 1/2 Amp for 5 seconds. I just can't see that happening.
It would greatly depend on the individual drive and I'm guessing the max current drain of 570mA would only be required initially, and for a very short period of time. I'd imagine the draw would drop off at an exponential rate for maybe 3 seconds total on a modern drive as the platters gain momentum. [It'd be fun to plot right?]
Plotting the current draw as one of the drives spins up, integrating over the time of increased draw, and multiplying by the number of drives to get a Coulomb would be a much better way of deciding what kind of caps are needed than assuming they would draw 1/2 amp for 5 seconds each...
Cheapass (Score:4, Interesting)
Rig some toggle switches on both power lines to each drive and have the operator manually turn on the drives as the machine is powering up.
Or do the right thing and go SCSI.
SCSI (Score:1)
1 - use some kind of SCSI adapter with your drives. This will not work. The support for delayed spinup is in the hardware of the drive itself - if you have a drive that doesn't support this feature (i.e. IDE drives) it won't work.
2 - set up some relays or something and switch the power going to the drives. This is a huge kludge, and will work with the following caveat - the drives (and controller) *must* be hot-swappable. Otherwise your system will crash when you start turning on the drives.
So unless this is a basement project - *go* *SCSI*!
Spin them up BEFORE you try to boot (Score:1)
By doing this, you could apply power to your drives before you boot, and use something similar to what's described above to spin them up.
This would allow you to control the high current draw by spinning the drives up in whatever order you'd like before you electrically remove the "spinner-upper" from the drive electronics and allow the computer to boot normally. (This is assuming that a 2nd spin-up signal from the BIOS wouldn't freak out the drive.)
You can find an IDE Hardware Reference & Information Document here [repairfaq.org].
To be very honest, I can't really see anybody implementing something as complex and convoluted as what's described above, particularly for multiple drives - but a properly programmed PIC chip or development board, with a bunch of IDE headers for the drives, that could spin up the drives however you'd like, then pass-through the original IDE signals from the motherboard, at boot time - POTENTIALLY, Potentially Could
You can see another suggestion of mine for this project here. [slashdot.org]
Good luck!
Could try SCR's (Score:2, Informative)
Simple solution... (Score:2)
Alternatively, you could use some kind of delay circuit to switch the drives in sequence, finally pulling the orange "power good" line to +5v.
Spinning up drives... (Score:2, Funny)
Be sure not to use excessive force while spinning up your tape drives, as you might stretch and tear the magnetic tape. This would most likely ruin the data stored on them.
7 drives on 400w no problem (Score:1)
http://leifcx.tripod.com/photos/hardware/leif.c
(copy and paste the URL, tripod cares too much about the referrer field)
The picture only shows 6 drives, I've added a drive since it was taken, right under the floppy drive. The 400W power supply powers all of them, including the floppy, two dvd drives and a cd writer, apparently without breaking a sweat.
You're not trying to run that many drives on a standard 200W supply, are you?
Keep in mind that the 400W spec is continuous power handling - it should handle way more than that momentarily, and that's probably what makes my setup work.
Just my two cents.
By the way, the server was serving my domain leif.cx until I moved and lost the DSL line. Damn it!
///Leif
IBM 75GXP support delayed spinup (Score:1)