Daisy Chaining External Hard Drives

[interlaced]

Can I "daisy chain" (i think that term is hilarious) two different external hard drives? I've never had experience with connecting two hard drives and I bought a new, bigger one to take the place of the other. However I think I might need both after all. Is it possible to connect a Seagate and LaCie (or any other brand) together and kind of make them act as one so I can also save a port on my macbook pro?

[hodgjy]

You can daisy chain the drives together and they will work just fune. They won't "act as one drive" as you say. OS X will recognize them as two completely different drives.

Also, you have to have the first drive in the chain turned on if you want the second drive to be recognized by OS X.

[pinkartstudent]

this is jsut waht i need to do - copy some stuff from my external HD to that of another editor. i have been told i can attach one to another: but how do i physically do this, pleae?

thanks in anticipation, D:confused:

[hodgjy]

Both drives have to be of the same connection type (usb or firewire). Plug the second drive into the available slot on the rear of one of the drives. Most firewire drives have an available slot, but not all usb drives do.

this is jsut waht i need to do - copy some stuff from my external HD to that of another editor. i have been told i can attach one to another: but how do i physically do this, pleae?

thanks in anticipation, D:confused:

[pinkartstudent]

but if i attach the first hd to the mac via firewire that's the port used up, so surely i'd only be left with a usb to usb connection for the second to the frist?

Sorry to be a pain ... D

[itickings]

but if i attach the first hd to the mac via firewire that's the port used up, so surely i'd only be left with a usb to usb connection for the second to the frist?

The firewire on the computer is used up physically, but if the firewire drive using the port has a second firewire port anything connected to that port will be accessible to the computer too.

Most firewire drives have two firewire ports. One to connect the drive to the computer, and another one to allow daisy chaining, ie connect an additional firewire unit.

Typical use:
Computer <-Firewire-> Drive A <-Firewire-> Drive B (and so on)

USB can't* do this, Firewire can.

*) OK, technically a drive could contain a built-in hub, but those are rare.

[pinkartstudent]

yes yes yes! connected laptop to my hd using firewire, then connected two hds together using firewire also. all worked fine (although i had to reconenct the media for some reason). thanks folks! :)

[loweevan]

I recently bought a new macbook to replace my 4 year old PowerBook G4. It was time for a new one. However, in dropping to the macbook, I've lost the firewire ports that I have used for my two external drives (one solely for backups, the other for large files that I use infrequently).

One drive is a LaCie with 2 FW800, 1 FW400, and 1 USB port (the square kind one frequently sees used with printers). The other drive is a WD mybook studio with 2 FW800, 1 eSATA, and 1 usb port. Both drives are powered. Previously I had daisy-chained the drives together using FW800, and connected to the computer the same way. Now, when I connect the two together and then run the USB from the WD to my computer, it doesn't recognize the LaCie drive. In fact, it won't recognize the WD unless I unplug the FW from it. After the computer detects it, I can plug the FW back in and it doesn't disturb anything.

USB can't* do this, Firewire can.
Do you mean that the drives all need to be connected USB <-> USB or FW <-> FW, or that USB simply can't daisy-chain? If USB is able to daisy-chain and the failing of my drives is that there is only one port (thus no port to plug the secondary into the primary), does a powered USB hub slow down connection speeds? I could just connect them both separately if speed isn't inhibited.

Sorry for the edit. I had missed a post that changed my question.

[sickmacdoc]

As I understand it you are currently trying to use a chain along the lines of:

Computer-----USB----->Drive 1------FW------>Drive 2

The results of this would match your observations. A FireWire cable between Drive 1 and Drive 2 will NOT be recognized. That only works if Drive 1 is connected to the computer via FireWire as well, as you had it before. The Firewire circuitry in the drives is independent of the USB circuitry, so what you are trying to do is impossible since there is no incoming data to the FireWire circuitry in Drive 1 to pass along (daisy chain) to Drive 2.

In answer to the second part, simply put USB has no daisy chaining ability. That is why there is only one USB on the back of the drives, as a second would be useless. To use multiple USB drives on a system with a single USB port yes you need to use a hub. As long as the powered hub is noted as being USB 2.0 compliant (as to opposed to ancient ones that were only USB 1.1 compliant) there will be no slowdown whatsoever compared to plugging a USB drive directly into the port on the computer.

USB 2, by it's very design specifications, is somewhat slower than FireWire 400 (and noticeably slower than it was if you were using FW 800 all the way in to the computer before as it appears you were) but there is no way around that.

[loweevan]

The Firewire circuitry in the drives is independent of the USB circuitry, so what you are trying to do is impossible since there is no incoming data to the FireWire circuitry in Drive 1 to pass along (daisy chain) to Drive 2.

In answer to the second part, simply put USB has no daisy chaining ability. That is why there is only one USB on the back of the drives, as a second would be useless.

Thank you. Understanding the circuitry is very helpful. I'm glad to know not only that it won't work, but also why.

USB 2, by it's very design specifications, is somewhat slower than FireWire 400 (and noticeably slower than it was if you were using FW 800 all the way in to the computer before as it appears you were) but there is no way around that.

I knew that the speeds would be a lot slower, and I've observed that already. I wish that it wasn't nearly $1,000 more for the mbp, but... so it goes.

Thanks again for your answer. I really appreciate it.

[armatt]

just wondering if (obviously this is theoretical) there is any limit to daisy chaining?

I use a 1TB Western Digital My Book for freelance filmmaking and am wondering how far ahead in advance i need to plan - ie: bite the bullet and get 2TB/4TB drive now while they're more expensive? or simply get another 1TB because that's all i need for now, knowing that i could daisy chain a third later on.

does anyone have any experience daisy chaining 3+ externals?

[jackerin]

just wondering if (obviously this is theoretical) there is any limit to daisy chaining?
Try googling for Firewire daisychain limit or something, iirc the limit is at 64 devices...

[maghemi]

just wondering if (obviously this is theoretical) there is any limit to daisy chaining?

I use a 1TB Western Digital My Book for freelance filmmaking and am wondering how far ahead in advance i need to plan - ie: bite the bullet and get 2TB/4TB drive now while they're more expensive? or simply get another 1TB because that's all i need for now, knowing that i could daisy chain a third later on.

does anyone have any experience daisy chaining 3+ externals?

I've had 3 daisy chained to each other working fine. However what you have to remember is they're all sharing the same firewire bandwidth. So if you're copying a large file to one of the three drives, and then trying to run things off another drive, they'll be sharing the bandwidth and hence slow down.