Can you connect a USB3.0 hard drive to an eSata port?

I have an HP Proliant N54L system that has an eSata port. I also have a spare USB3.0 3TB spinning disk external harddrive that I want to hook up to my proliant.

Is it possible to connect the drive to the port?

For the down voter .. cables like this exist to provide adaption in the opposite direction I require. Thus it seems technically possible.

Note that I know there are USB ports on the proliant that I can use, but I am running FreeNAS on the system and booting off a USB flash drive connected to an internal port. You can't control the USB boot order on the system and HP prioritized the external USB ports over the internal ones. So if I connect my external drive to a USB port then the damn machine can't re-boot. And under FreeNAS you just can't pull it out and then reconnect it - you have to do a bit of fiddling around. I am trying to avoid doing this.

Peter M

Posted 2017-07-17T21:02:37.027

Reputation: 1 099

Just curious, why do you prefer a SATA connection over USB3? USB3 is nearly as fast as SATA 6GB. And you said performance isn't an issue. And USB3 adapter cards for computer/laptop are no more expensive than the cable you're looking for would be. – Cliff Armstrong – 2017-07-17T22:31:00.693

@CliffArmstrong My hardware choices are USB2.0 or eSATA on the N54L. And if I choose USB the system won't automatically reboot as there is nothing to boot from on my USB based drive! I bought a USB3.0 drive to start future proofing things (knowing that it may one day be shifted onto another computer) – Peter M – 2017-07-17T22:36:28.653

The N54L has two expansion slots which I assume are filled already so no USB3 expansion card. And that cuts off the eSATAp option cause you'd need an expansion card for that as well. BTW, you can't configure your system to not to try to boot from USB or to put that USB device last in the boot order? There would be BIOS options for that on a consumer PC.. seems like an odd thing to leave out in a server.

– Cliff Armstrong – 2017-07-17T23:13:21.663

When you say USB 3.0 hard drive, do you actually mean a hard drive within an enclosure with a USB 3.0 controller, or are you referring to a flash/thumb drive? – Norr – 2017-07-18T02:29:37.737

@CliffArmstrong I am trying to get away from USB. I currently can't control the USB boot order in the BIOS so I am hesitant to add a USB3.0 expansion card (BTW the slots are free). By going to eSata I was hoping to get away from that mess. – Peter M – 2017-07-18T11:00:00.933

@Norr I have a 3TB USB3.0 spinning disk external hard drive – Peter M – 2017-07-18T11:00:25.170

@Peter M Then as previously stated in the discussion, your best option in this situation is to remove the hard drive from the enclosure and use an eSATA to SATA adapter – Norr – 2017-07-19T11:28:19.200

Answers

SATA port and USB port use completely different protocols, and you can't connect one to the other.

However, nearly all USB harddrives are really SATA drives in an enclosure that has an USB-to-SATA bridge. Try to open your USB enclosre, take the harddisk out, get a SATA-to-eSATA adapter if necessary, and connect it to the eSATA port.

Edit Background:

The USB-to-eSATA "cable" contains the same kind of USB-to-SATA bridge as used in USB enclosures for harddisks. This bridge is a small computer on a single chip, with an USB port at one end and a SATA port at the other end, and software that translates from one to the other. The chip is small enough you can hide it in the cable, either in the plug at one end, or in a bulge in the middle.

Yes, in theory it would be possible to use a similar chip that translates in the other direction as well (restricted to USB storage devices), but nobody needs those (just use the driver directly, as I've described), so nobody makes those, so you can't buy them.

dirkt

Posted 2017-07-17T21:02:37.027

Reputation: 11 627

How do you explain USB3.0 port to eSata peripheral cables then? EG https://www.newegg.com/Product/Product.aspx?Item=N82E16812400574 or is that a media converter the middle?

– Peter M – 2017-07-17T21:10:09.497

1The bulge in the cable (second image) is an active protocol adapter. It can speak to the computer over USB and then to a hard drive over Sata. It doesn't mean that USB = SATA – Mokubai – 2017-07-17T21:35:41.593

@Mokubai I'm not suggesting that USB = SATA, but the existence of this cable shows that adaptation in one direction is possible. I just want adoption in the other direction. – Peter M – 2017-07-17T21:41:53.830

A large part of it will be to do with needs, most people will have a USB connected computer and may randomly happen across eSATA disks, they are much less likely to only have eSATA and need to connect to a USB drive. – Mokubai – 2017-07-17T21:48:04.693

Also, USB is a universal serial bus designed for use with any peripheral, often through active-adaptation. SATA doesn't make any of the allowances for unknowable connected devices that USB does. For example... SATA doesn't provide power on the wire while USB does. So while it's hypothetically possible to put some sort of adapter in the wire that would let you use a USB device on a SATA bus... you'd probably also have to plug it into the USB bus to get power for the SATA-USB adapter. At which point... why bother? – Cliff Armstrong – 2017-07-17T22:04:08.067

In theory you could, you would need a protocol converter cable so that your laptop's eSATA signals could be converted to USB3 and go to the external hard disk enclosure, where they would be converted back to SATA to "talk" to the disk.

Performance-wise, let's say it's not optimal.

There is also another problem: while USB3 provides a power supply, eSATA (natively) does not. So you would need an external power source, you couldn't just plug the cable and connect it to the enclosure.

The bundle you need to purchase, then, will of necessity be more expensive and less performant than an external eSATA enclosure; most of which enclosures additionally already have dual input (USB3 and eSATA), which makes the "cable" solution less flexible, too.

In other words, economically it would make little sense to build such a powered cable, because it would have next to no market; only people with a USB3 device they can't replace and can't open.

If you found such a cable, chances are that it was designed to work only with a very specific laptop.

LSerni

Posted 2017-07-17T21:02:37.027

Reputation: 7 306

Performance wise I don't care as it is a backup to my backup system and will only be accessed in the wee hours of the morning. BTW the enclosure you linked to is not eSata. But I am getting an idea that I may be trying to beat a dead horse – Peter M – 2017-07-17T22:26:51.530

Sorry, fixed the Amazon link to another enclosure (there are 3.5" enclosures too, saw them on Amazon). But what about a eSATA-to-SATA (with power) as @dirkt suggested? – LSerni – 2017-07-17T22:40:58.523

I have this really nice USB3.0 enclosed 3TB hard drive. I really don't want to butcher the USB3.0 case just to put the drive into another case. – Peter M – 2017-07-17T22:43:00.890

That's understandable! But you might get a PCIe USB3 card perhaps, and get a USB3 connection that way? – LSerni – 2017-07-17T23:11:12.580

I am wary of adding a USB3.0 card PCIe as I can't control the current USB boot order in BIOS and I am not sure if I will end up in the same boat. – Peter M – 2017-07-18T11:03:06.600

This keeps getting more difficult :-). But I think you can install GRUB on the external disk, instructing it to chain to the correct disk, should it ever gain control of the boot process. – LSerni – 2017-07-18T11:22:09.117

You think this is bad? I was just looking at an eSata case whose website says its compatible with Windows and OS X but doesn't work under Linux (besides which I am using FreNAS which is BSD based). I emailed the supplier and they conformed that statement. Mind boggled. – Peter M – 2017-07-18T13:03:00.743

I'm trying to think of an honest technical reason why it couldn't be done and I'm drawing a blank except that USB is a much more feature filled protocol than SATA, what with it being used from everything from mice to printer to hard disks.

Consider the cable you linked, it would have the following:

USB host (computer) => USB client (HDD profile) => SATA Host => SATA Disk

What you want is

eSATA host (computer) => SATA client => USB Host => USB Disk

The USB host side would potentially need a larger amount of logic than the SATA host side. De-packetizing USB and repackaging it as SATA would require a large amount of work, especially at USB3 speeds. The converse (first adaptor) will have been done in every USB based hard drive already, the silicon has already been made a thousand times over.

It is also probably also a lot easier using the computer-host USB, it was always intended to support hard drives and so almost certainly is intended to support disk commands with only minimal repackaging of data.

Mokubai

Posted 2017-07-17T21:02:37.027

Reputation: 64 434

You would also need a power source for the SATA-USB adapter. SATA doesn't provide enough power on the data line. And the most obvious choice would be a USB port... but if you end up using up a USB port anyway, why would you bother? I suppose you could have a power adapter going to a wall outlet... What's interesting are the old eSATA/USB3 combo ports I used to see. That might offer a solution... but I've not seen those in a while. – Cliff Armstrong – 2017-07-17T22:06:51.343

1@CliffArmstrong My USB drive already has an external PSU but no idea if it can back fill the USB cable – Peter M – 2017-07-17T22:07:51.600

Oh, sorry, I see what you mean, and no. The way USB is designed that would not happen. It has a power lead and a ground lead. But the only power source is supposed to be at the hub/computer. The devices are very intentionally made so that any power provided directly to them does not leak back to the USB hub/computer. If it did it could potentially damage them. – Cliff Armstrong – 2017-07-17T22:23:44.567

@CliffArmstrong Also see the link provided in LSerni's answer and also this one https://en.wikipedia.org/wiki/ESATAp about eSata power. It seems eSATAp exists to fill this power void. But I know I won't have the eSATAp!

– Peter M – 2017-07-17T22:32:42.983

no eSATAp showed up for a very short time right before USB3 landed and then disappeared cause USB3 pretty much replaced it. That's what I was talking about with the eSATA/USB3 combo ports, that's what eSATAp actually is. – Cliff Armstrong – 2017-07-17T23:16:46.097