[asterisk-users] No-mobo PC for USB Drives Enclosure?

Wed May 14 02:41:48 CDT 2008

As people have sugested the ATX power supplies can work without a mobo
One thing to watch out for your setup is the actual ampere requirments for
your disks
i.e Your power supply provides 300W but this is "partitioned" to different
voltages (+5, +12, etc) with different amp charecteristics
Disks need 2 voltages. One for the logic (+5V) and one for the motors (+12V)
and have different current requirments.
Most disk (if not all) mention these ratings on the labels they have
What you must do, is to see if by adding the current requirments seperatly
for +5V and +12V, does not exceed the power supply's amp rating *for that
voltage*, allowing also for a 15% -20% margin, as power consumption will be
higher than the nomimal mentioned during disk startup (and you will be
starting all your disks at the same time)
Also make sure your box has sufficient cooling and there is some short of
airflow over the disks, as the number 1 enemy of disks is high temperature
and stacking so many disks in a box will create large amounts of heat.

I would suggest you to get a good (aka expensive) 500W power supply and use
10-12 disks with it to avoid problems in the long run,
Also keep in mind that MTBF specs of SATA disks does not make them an ideal
candidate for 24/7/365 operations

Stelios S. Koroneos

Digital OPSiS - Embedded Intelligence
http://www.digital-opsis.com

> -----Original Message-----
> From: asterisk-users-bounces at lists.digium.com 
> [mailto:asterisk-users-bounces at lists.digium.com] On Behalf Of 
> Matthew Rubenstein
> Sent: Wednesday, May 14, 2008 7:31 AM
> To: Col Ferguson
> Cc: Asterisk -Users
> Subject: Re: [asterisk-users] No-mobo PC for USB Drives Enclosure?
> 
> On Wed, 2008-05-14 at 14:06 +1000, Col Ferguson wrote:
> > If I understand right, your problem is that the power 
> supply won't turn on ?
> > ATX power supplies can be told to turn on by jumpering 2 
> pins on the 
> > motherboard power connector. From memory its the Green wire 
> and one of 
> > the black wires, I usually use the next one inwards. 
> Pinouts for the 
> > connector can be found via Google.
> > If the power supply also has an external on/off switch you 
> can jumper 
> > these pins and use the switch to turn the power on or off.
> > 
> > Hope this helps,
> 
> 	Thanks, that sounds like exactly what I was looking 
> for. Is there any safety risk from jumpering that sensor? 
> Like some kind of extra sensor, like voltage feedback, 
> temperature or somesuch.
> 
> 	If this works, it might point to a good way to reduce 
> redundant Asterisk servers, which suck power, by just 
> plugging the drive from each old server into the USB of a 
> single server with a merged dialplan and a few other tweaks 
> to point at several different mounted drives, rather than one 
> per host/IP#.
> 
> 
> > Col
> > 
> > 
> > 
> > ----- Original Message -----
> > From: "Matthew Rubenstein" <email at mattruby.com>
> > To: "Asterisk -Users" <asterisk-users at lists.digium.com>
> > Sent: Wednesday, May 14, 2008 12:22 PM
> > Subject: [asterisk-users] No-mobo PC for USB Drives Enclosure?
> > 
> > 
> > > I have over a half-dozen different SATA hard drives, each with 
> > > different data (configs, voiceprompts, voicemail, CDRs, AGIs) for 
> > > each one's different user groups and applications. Each 
> one's load 
> > > on the Asterisk server is small enough that one server 
> can host them 
> > > all, accessed easily over USB.
> > >
> > > But right now, each one is in its own external USB enclosure on a 
> > > powered USB hub. I want to combine them all into a single large 
> > > enclosure. I tried to use a single PC chassis, leaving 
> the USB hub 
> > > inside with the drives screwed into it, and powered from the PC 
> > > power supply as internal drives on the proper drive power output 
> > > plugs. But without a PC motherboard plugged into the 
> power supply, 
> > > too, the power supply won't start up to power the drives.
> > >
> > > I don't want to add a motherboard: that costs money, and sucks 
> > > power, and is totally unnecessary. I just want to make 
> this gutted 
> > > PC chassis power my drives only, and have them connect to the 
> > > complete PC sitting next to it via the single USB cable 
> coming out 
> > > of the drive chassis. How do I do that?
> > >
> > > Is it possible to use the extra, unused floppy power 
> plugs to power 
> > > more hard drives, with an adapter? Is it possible to split the 
> > > existing hard drive power plugs to each power multiple 
> drives? How 
> > > many drives can I split each power plug into? The power 
> supply is a 
> > > cheap 300W unit, and the drives draw max under 9W each:
> > > http://www.wdc.com/en/products/products.asp?driveid=311 . 
> So can I 
> > > power 25-30 of these drives, or at least 10?
> > > --
> > >
> > > (C) Matthew Rubenstein
> > >
> > >
> > > _______________________________________________
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> > 
> -- 
> 
> (C) Matthew Rubenstein
> 
> 
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