If there are a PC and two separate network drives (in two separate boxes), and you use Windows Explorer on the PC to copy a big folder from one drive to the other, are you transmitting the data twice - from one drive to the PC, and thence to the other drive? Or does the system somehow understand how to transmit the data from one network drive to the other?
If it matters, the drives are Linksys Gigadrives that run, I think, some kind of Linux, and the PC is running XP.
I could very easily be wrong, but it’s my understanding that the PC would first copy a part of the data from the first hard drive to its RAM, then copy it onto the second hard drive, then repeat until all the data has been moved.
You’re copying it over the wire from one drive to the PC and then from the PC to the other drive.
This is happening per packet; it’s not like the whole file is copied first to the PC as a unit and then recopied as a unit to the second drive.
Yes, this is what happens, and using your PC as a middleman can be a performance penalty of if you’re copying a large amount of data.
To get this behavior, some devices have a web interface with an administrative feature to backup itself to another drive (connected via network or USB). In this way, you tell the the embedded linux operating system to copy the data without involving your PC.
I wouldn’t know if your specific Linksys has this capability.
You’d think it’d do that, wouldn’t you? Just be glad moving files from one folder to another doesn’t cause such a copy. Usually.
It actually does. But the way I am using things does not take advantage of this. I have two of these, and one of them contains two hard drives, while the other contains only one. All drives are equal in size. I have given two of us quotas on the single-drive device so we can each use half the space, and we each have one drive on the other device. Plan A was that the two-drive box would be out in the barn, and we could each back up our half of the single box into our one drive in the dual box, and we could have two backups (which we’d alternate). But the network cable run to the barn, at around 200 feet, appears too long (it only allows slow data transfer rates and copying a big folder always crashes after a few dozen files). I thought cables could go up to 330 feet or something; apparently not. So Plan B is logically the same thing but physically both boxes are in the house, so if the house burns so do our files. I bought a couple of switches to break this 200 foot cable into three shorter segments but haven’t installed all that yet.
The boxes are able to regularly schedule a backup between drives within a box, but since I want backups in a separate building, and since I didn’t have a second drive in one of them, I didn’t take advantage of it.
The wire you are using may have shielding problems. It may not even be designed for use outside.
My church, while it uses hundreds of feet of wire inside, uses an amplified Wifi connection between the two buildings.
The wire is partly in plastic conduit along a fence and partly in a buried plastic pipe. It’s dry, but not heated. It’s Cat 5E. I don’t remember if it’s plenum or not, but understand that’s a flame retardancy spec, not an electrical one.
What kind of shielding problems or other wire problems apply? I’ve never heard of shielded Ethernet wire.
I thought about WiFi - in fact, I had a spare 75 ohm wire already buried, and bought WiFi to send down the cable. That’s right - I went through impedance matching transformers from the antenna jacks on two wireless bridge units. The trouble was that the cable got lossy enough in warm weather that the signal would get too weak. In the winter it worked fine, though. Before they brought CATV to this area, I got my broadband from a DirecWay dish out there (the house can’t see the satellite).
I also considered WiFi with dish antennae through the air. I know several people that break into other folks home wireless systems for fun, though, which always gives me the impression that it isn’t very secure. That, and what seems like wireless security patches and fixes that get announced several times a year. And the neighbor who lives just past the barn is a hacker.
In fact Mrs. Napier got an IT guy to buy and configure a laptop for her, at home. He worked for a while and announced that he was finished, had everything working fine including the wireless network. Trouble is, we don’t have a wireless network.
For long outdoor runs there can be grounding issues. They’re also long antennas, and are susceptible to frying network equipment if lightning strikes nearby.
The best way is fiber optic. A terminated cable and transceivers would run about $300. Let me know if you want details.