Re: OT: Using a USB hub with 3 computers, 1 printer, 1 external drive (for backup for any of the three PCs)

[Leslie Rhorer]

Well, OK, yeah.  It is not entirely impossible.  Few things are.

On 6/5/2020 10:13 AM, to...@tuxteam.de wrote:

On Fri, Jun 05, 2020 at 09:52:34AM -0500, Leslie Rhorer wrote:

As already mentioned, this simply will not work.


As already mentioned in this thread, this isn't strictly true.
There is USB "on the go" (aka OTG [1]); this has even a protocol
to switch masters. That makes sense for mobile devices, which
have to play slave when being attached to a computer (sync and
things) and have to play master when stuffing a storage stick
into them.

But at any time there can only be one master on an USB tree.

And the hardware has to play along.


   Why are you
wanting to employ USB  Ethernet / TCPIP is the way to go.  Make the
external drive a NAS, and you are good to go.  Many NAS systems
support printer sharing, or you can roll your own.


USB is no replacement for networking, no.

Cheers
-- tomás

Re: OT: Using a USB hub with 3 computers, 1 printer, 1 external drive (for backup for any of the three PCs)

[tomas]

On Fri, Jun 05, 2020 at 09:52:34AM -0500, Leslie Rhorer wrote:
>   As already mentioned, this simply will not work.

As already mentioned in this thread, this isn't strictly true.
There is USB "on the go" (aka OTG [1]); this has even a protocol
to switch masters. That makes sense for mobile devices, which
have to play slave when being attached to a computer (sync and
things) and have to play master when stuffing a storage stick
into them.

But at any time there can only be one master on an USB tree.

And the hardware has to play along.

>   Why are you
> wanting to employ USB  Ethernet / TCPIP is the way to go.  Make the
> external drive a NAS, and you are good to go.  Many NAS systems
> support printer sharing, or you can roll your own.

USB is no replacement for networking, no.

Cheers
-- tomás


signature.asc
Description: Digital signature

Re: OT: Using a USB hub with 3 computers, 1 printer, 1 external drive (for backup for any of the three PCs)

[Leslie Rhorer]

	As already mentioned, this simply will not work.  Why are you wanting 
to employ USB  Ethernet / TCPIP is the way to go.  Make the external 
drive a NAS, and you are good to go.  Many NAS systems support printer 
sharing, or you can roll your own.


On 6/4/2020 1:46 PM, rhkra...@gmail.com wrote:

In a way, the subject covers most of it: " Using a USB hub with 3 computers, 1
printer, 1 external drive (for backup for any of the three PCs)".

I don't know much about USB hubs, I guess all of the ports are two way.

To clarify, if needed, I'd like to buy a 5 (or more) port USB (3.0) hub to
connect 3 PCs, 1 printer, and 1 external drive such that I can print or backup
from any of the 3 pcs.

I suppose there are two questions:

1.  Should I expect any problem "hardware wise"?

2. I suppose I have to consider the mounting of the partitions on the
drives, I suppose it would be a bad idea to have the same partition (or even
drive) mounted on more than one pc at the same time?

(And I guess I'd have to avoid printing from two computers at the same time.)

Re: OT: Using a USB hub with 3 computers, 1 printer, 1 external drive (for backup for any of the three PCs)

[rhkramer]

Thanks to all who replied!

On Thursday, June 04, 2020 05:14:29 PM Gene Heskett wrote:
> On Thursday 04 June 2020 14:46:50 rhkra...@gmail.com wrote:
> > In a way, the subject covers most of it: " Using a USB hub with 3
> > computers, 1 printer, 1 external drive (for backup for any of the
> > three PCs)".

Re: OT: Using a USB hub with 3 computers, 1 printer, 1 external drive (for backup for any of the three PCs)

[Gene Heskett]

On Thursday 04 June 2020 14:46:50 rhkra...@gmail.com wrote:

> In a way, the subject covers most of it: " Using a USB hub with 3
> computers, 1 printer, 1 external drive (for backup for any of the
> three PCs)".
>
> I don't know much about USB hubs, I guess all of the ports are two
> way.
>
> To clarify, if needed, I'd like to buy a 5 (or more) port USB (3.0)
> hub to connect 3 PCs, 1 printer, and 1 external drive such that I can
> print or backup from any of the 3 pcs.
>
> I suppose there are two questions:
>
>1.  Should I expect any problem "hardware wise"?
>
>2. I suppose I have to consider the mounting of the partitions on
> the drives, I suppose it would be a bad idea to have the same
> partition (or even drive) mounted on more than one pc at the same
> time?
>
> (And I guess I'd have to avoid printing from two computers at the same
> time.)

cups can handle that on your local network, configure cups to run the 
printer and mark it as shared. Then with cups installed on the other 
machines, they can use those printers just as if they were local to that 
machine. I am doing that on a 5 machine local net here. Even works if 
you have 2 printers. You'll get your exercise going after the printout, 
but I see that as just getting some exercise I need but might not 
otherwise get. :-) 

Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 

Re: OT: Using a USB hub with 3 computers, 1 printer, 1 external drive (for backup for any of the three PCs)

[Dan Ritter]

rhkra...@gmail.com wrote: 
> In a way, the subject covers most of it: " Using a USB hub with 3 computers, 
> 1 
> printer, 1 external drive (for backup for any of the three PCs)".
> 
> I don't know much about USB hubs, I guess all of the ports are two way.
> 
> To clarify, if needed, I'd like to buy a 5 (or more) port USB (3.0) hub to 
> connect 3 PCs, 1 printer, and 1 external drive such that I can print or 
> backup 
> from any of the 3 pcs.

Others have told you why this won't work.

Let's explore other ways that you can achieve the same goals.

I'm going to assume that all 3 PCs are connected to a local
network, and you can get 

Goals:

1. Print from any PC to the printer

2. Backup from any PC to the backup disk

Is that correct?

If so:

1. Printing:

- if the printer has an ethernet port, plug it in to your
  network. If it has wifi, turn that on. Done.

- if the printer does not have an ethernet port, plug it in to
  a computer that will always be on when you need to print,
  and share it on the network with CUPS. (Debian provides 
  a CUPS server.)

- if CUPS doesn't make you happy, install Samba and share with
  that.

2. Backup

- Debian machines can backup over the network to a machine where
  the USB disk is plugged in. 'backupninja' can help configure
  that.

- Windows machines can backup over the network to a Debian
  machine where the USB disk is plugged in. Samba is the key
  here.

- Mac OS X machines can backup over the network to a Debian
  machine where the USB disk is plugged in. netatalk is the key
  here -- it can be used for native Time Machine backups.

Happy to help.

-dsr-

Re: OT: Using a USB hub with 3 computers, 1 printer, 1 external drive (for backup for any of the three PCs)

[tomas]

On Thu, Jun 04, 2020 at 08:53:26PM +0200, Sven Hartge wrote:
> rhkra...@gmail.com wrote:
> 
> > In a way, the subject covers most of it: " Using a USB hub with 3 
> > computers, 1 
> > printer, 1 external drive (for backup for any of the three PCs)".
> 
> > I don't know much about USB hubs, I guess all of the ports are two way.
> 
> No. This is even enforced in the way the cables and connectors are
> designed.
> 
> > To clarify, if needed, I'd like to buy a 5 (or more) port USB (3.0) hub to 
> > connect 3 PCs, 1 printer, and 1 external drive such that I can print or 
> > backup 
> > from any of the 3 pcs.
> 
> No.
> 
> USB is a tree, there can only be ever one root. You can't connect three
> PCs to a USB hub and expect this to work.
> 
> > I suppose there are two questions:
> 
> >1.  Should I expect any problem "hardware wise"?
> 
> Yes, because it will not work.
> 
> There are very special USB sharing devices which allow more than one
> computer use connected devices, but those are a) rate and b) expensive.

Right. An USB tree has one "host" (aka "master") and several "devices"
(aka "slaves"). The latter can only talk to the "host". Some can switch
roles (as specified by the USB "on the go" (OTG) [1] spec. Typically
tablets and smartphones can do this. Linux seems to support that, but
the USB hardware has to play along [2]. Note that I haven't tried it.

Cheers

[1] https://en.wikipedia.org/wiki/USB_On-The-Go
[2] 
https://unix.stackexchange.com/questions/386945/configure-linux-system-as-an-otg-device
-- t


signature.asc
Description: Digital signature

Re: OT: Using a USB hub with 3 computers, 1 printer, 1 external drive (for backup for any of the three PCs)

[Joe]

On Thu, 4 Jun 2020 14:46:50 -0400
rhkra...@gmail.com wrote:

> In a way, the subject covers most of it: " Using a USB hub with 3
> computers, 1 printer, 1 external drive (for backup for any of the
> three PCs)".
> 
> I don't know much about USB hubs, I guess all of the ports are two
> way.
> 
> To clarify, if needed, I'd like to buy a 5 (or more) port USB (3.0)
> hub to connect 3 PCs, 1 printer, and 1 external drive such that I can
> print or backup from any of the 3 pcs.
> 
> I suppose there are two questions:
> 
>1.  Should I expect any problem "hardware wise"?
> 
>2. I suppose I have to consider the mounting of the partitions on
> the drives, I suppose it would be a bad idea to have the same
> partition (or even drive) mounted on more than one pc at the same
> time?
> 
> (And I guess I'd have to avoid printing from two computers at the
> same time.)
> 

Sorry, no, it's not going to work. USB is a master-submaster-slave
protocol, and there can only be one master. It's not peer-peer.

This sort of situation is why Ethernet was invented.

-- 
Joe

Re: OT: Using a USB hub with 3 computers, 1 printer, 1 external drive (for backup for any of the three PCs)

[Sven Hartge]

rhkra...@gmail.com wrote:

> In a way, the subject covers most of it: " Using a USB hub with 3 computers, 
> 1 
> printer, 1 external drive (for backup for any of the three PCs)".

> I don't know much about USB hubs, I guess all of the ports are two way.

No. This is even enforced in the way the cables and connectors are
designed.

> To clarify, if needed, I'd like to buy a 5 (or more) port USB (3.0) hub to 
> connect 3 PCs, 1 printer, and 1 external drive such that I can print or 
> backup 
> from any of the 3 pcs.

No.

USB is a tree, there can only be ever one root. You can't connect three
PCs to a USB hub and expect this to work.

> I suppose there are two questions:

>1.  Should I expect any problem "hardware wise"?

Yes, because it will not work.

There are very special USB sharing devices which allow more than one
computer use connected devices, but those are a) rate and b) expensive.

Grüße.
Sven.

-- 
Sigmentation fault. Core dumped.

OT: Using a USB hub with 3 computers, 1 printer, 1 external drive (for backup for any of the three PCs)

[rhkramer]

In a way, the subject covers most of it: " Using a USB hub with 3 computers, 1 
printer, 1 external drive (for backup for any of the three PCs)".

I don't know much about USB hubs, I guess all of the ports are two way.

To clarify, if needed, I'd like to buy a 5 (or more) port USB (3.0) hub to 
connect 3 PCs, 1 printer, and 1 external drive such that I can print or backup 
from any of the 3 pcs.

I suppose there are two questions:

   1.  Should I expect any problem "hardware wise"?

   2. I suppose I have to consider the mounting of the partitions on the 
drives, I suppose it would be a bad idea to have the same partition (or even 
drive) mounted on more than one pc at the same time?

(And I guess I'd have to avoid printing from two computers at the same time.)