What 1TB USB drive to add for USB schedule backups (with Buffalo pro XHL)?

[gberche]

Hello,

I'm considering buying a Buffalo Pro XHL and associating it with a USB drive to perform scheduled backups. I'm quite interested in keeping the power consumption low and unattended backups. I would schedule sleep mode on the XHL to be up at very restricted time slots (basically the evenings where I'll be using the drive at home remotely from my laptop). I expect the USB attached drive to shutdown when the Buffalo XHL enters sleep mode.

I got the Buffalo support to confirm that with USB-powered drive, the sleep mode also shutdowns the USB drive, see http://forums.buffalotech.com/buffal...thread.id=8810 however they did not indicate which USB drive they tested, and won't give a compatibility list.

What USB drive 1 TB would you recommend?

I've looked at Western Digital My Book Essential Edition 2.0 - 1 To, but I'm not sure it would shutdown automatically when the Buffalo XHL pro would enter sleep mode.

I looked at USB drive enclosures, but they seem to always get external supplys with manual switches (suggesting to me the disk would'nt shutdown from the USB signalling sent by the buffalo XHL nas)

Anybody tested this configuation yet and can advice?

Thanks in advance,

Guillaume.

[thiggins]

Response from Buffalo:

It depends on the USB drive. It needs to be a USB drive that can shut off the drive when it detects no USB power. Most Buffalo USB drives have this setting (except the latest entry-level DriveStation and the Combo4). The original DriveStations, the DriveStation Duo, the DriveStation Quattro, and the DriveStation Combo all support this feature.

He will need to check with his USB HDD manufacturer for the support of this feature, but in most cases it's not a standard feature.

[gberche]

Thanks Tim for getting this answer from Buffalo.

So if I understand well their advice, they're expecting USB drives with an independent AC power supply to detect the lack of USB power with the USB cord to the Buffalo attached main NAS so that the USB drive shuts down.

Originally, I was trying to find USB drives powers from the USB cord without an independent power supply. I know some legacy USB disk enclosure for IDE drives did power the IDE drive from the USB power line.

Do you think I could be able to find such USB-powered USB drives more easily than USB drives that detect lack of power on their USB cord to shutdown (non standard as Buffalo support was replying to you?)

Next question is whether Buffalo own power supply would indeed cope with two drives (the WD internal green caviar and the external USB drive) .

Again, I did not get Buffalo support to respond on this in their forum at http://forums.buffalotech.com/buffal...ump=true#M9195

Thanks again for your help and your future insights about this.

Cheers,

Guillaume.

[thiggins]

The problem is that the USB 1.1 and USB 2.0 protocols limit bus supplied power to 2.5 Watts (0.5A @ +5V) per port. Hard drives are power-hungry, especially during power-up, so have a difficult time meeting this spec. So they need to have their own power supplies.

This is a USB spec limit, not a Buffalo limit.

[gberche]

Thanks Tim for the precision over the USB specs explaining me why indeed an external supply is needed.

Would cheap USB enclosure such "advance BX-3706SI" which are not providing a power supply, only work when connected to a desktop PC allowing on its USB port higher power supply than the specs enforce? So I assume that if I plug these cheap USB enclosure to my futur Buffalo Pro XHL, I may dammage it. You confirm?

I studied further Buffalo Drive Station FlexNet HD-CE1.0TLU2 as a solution for a Buffalo USB drive that I could use as a backup attached to my future Buffalo Pro XHL.

The specs on your review at http://www.smallnetbuilder.com/index...ge=2&Itemid=75 mentions a power consumption of "12 W when active and 5 W when the "Eco Management" drive spin-down kicks in after 10 (default), 20, 30 or 60 minutes of idle time."

When my future Buffalo Pro XHL would enter sleep mode and signal through the USB cord to the Drive Station stop of USB power, what is the consumption I should expect from the Drive Station: 5W as in automatic idle mode, or less than that?

The advantages I saw for the Drive Station as a backup drive are:
- compatible with Buffalo Pro XHL
- primary ethernet support (to perform network backups from different part of the house as to minimize loss/thief of both drives)

The cons I saw were:
- a bit of cost (sells to 190E whereas seagate barracuda drive + USB is 120E)
- size: harder to fit in the pocket and attach to a laptop
- slow USB and ethernet performance (while this would be fine for a backup solution)


If this is 5W, then shouldn't I rather go with a Seagate Barracuda 1TB (advertising 5 to 9.4W consumption http://www.seagate.com/staticfiles/d...da_7200_12.pdf) and wrap it with a USB enclosure? Which USB enclosure could you recommend in this case?

Thanks again,

Guillaume.

[thiggins]

I'm sorry, Guillaume. But I have not tested or used USB enclosures. So I can't provide any further advice or guidance.

[thiggins]

Some additional info from Buffalo:

I was investigating some info on WD and saw on their USB product web site they have a feature sheet where they market the Auto On/Off with your Computer feature.

http://www.wdc.com/en/products/index...=8&language=en

This is the same feature I spoke of in regards to our sleep mode. There is no standard for this and every manufacturer will call it something different, but the consumer will need to look for comparable verbiage if they're interested in this function.

[gberche]

Hi,

Here are my conclusion after a few more studies:
- NAS manufacturers, and USB drives manufacturers make it very hard for consummers to be concious of power consumption: almost no product's manual or tech specs clearly display their power consumption even less the variation of power under the various operation modes (active, idle, standby, shutdown)
- Power mode saving are not standard, and each manufacturer has it own mechanism (PC hosted software signaling the drive to shutdown, relying on the disk own power saving support after inactivity periods, or USB signalling detection on the drive...), making it hard for consummers to anticipate power saving compatibility modes especially when using a USB drive within a NAS.
- Some internet reviews such as smallNetBuilder and others such as Tomas hardware http://www.tomshardware.com/reviews/...e,2045-16.html do display power consumptions but they are not consistent among each other. For example Tom's hardware reports a Western Digital My Book Essential Edition 2.0 - 1 To , with 10.2 W when active, 8 watt inactive, 7 watts sleep mode, and 0.4 w when shutdown. Some other reviews reported much higher consumption.

- For my USB drive to support USB backup to my Buffalo XHL NAS, I'll go with a Western Digital My Book Essential Edition 2.0 - 1 To (USB 2.0) because it is cheap, reasonnable fast with USB2 interface, robust, widely available and offers 2-3 years warranty, and seems in the average of power consumption.

Oher closest candidates were in order: La Cie design by Neil Pulron 1TB (less robust and more expensive, although smaller power consumption), and SimpleTech Prodrive 1 TB (not available in Europe although reported as best buy by Tom's hardware).

I hope this post can help others, and that manufacturers will be more transparent with this as the power consumptions more widely becomes a criteria in consumers purchase decisions.

Cheers,

Guillaume.

[thiggins]

Thanks for your post, Guillaume.