Same Backup/External Drive for A Mac and A PC?
March 16, 2015 6:08 PM   Subscribe

This might sound like a strange question, but I have two computers, a Macbook and PC. If it matters, the Windows PC is online; the Macbook is almost never online. (This is why I'm not using a cloud service.) I'd like both of them to be hooked up to the same external drive (or some kind of backup drive), so I can pass files between the two, WITHOUT using the wireless network. I'm assuming I need to use hard cables for both, which is fine.

Is this even possible? What would I need to buy or install?

I thank you for any suggestions.
posted by neeta to Computers & Internet (13 answers total) 3 users marked this as a favorite
As far as I know, unless things have changed, Macs and PC read hard drives differently. You may need a program like Mac Drive to do that, but I'm not sure how it would work out. All I know is that when I needed to get files from an external hard drive that had been used with a Mac a few years ago, I couldn't read them when I hooked it up to my PC and so I needed to download Mac Drive. I think it works the opposite way though -- a hard drive used on a PC can be read on a Mac computer. (Macs are dumb.)
posted by AppleTurnover at 6:13 PM on March 16, 2015

AppleTurnover's information is out of date.

Microsoft created the exFAT file system in order to address the problem of neither the old NTFS or FAT32 formats being optimal for large-format removable media like big flash drives or hard drives. exFAT appeared in Windows Vista SP1, and is supported out of the box by Windows 7 and 8.

As of Mac OS 10.6.5, Mac OS also natively supports exFAT. You can even format a hard drive as exFAT within Mac OS. So, you can get yourself a USB hard drive, format it exFAT on either the Windows machine or the Mac, and then plug it into any Mac or Windows machine from Vista SP1 or 10.6.5 on. It's easy these days.

That said, a non-network USB hard drive can only be connected to one of the machines at once, so you'll need to disconnect it from one machine and connect it to the other for each transfer. If you just want to be able to pass files between the machines in a one-step operation, you could connect the two machines with an Ethernet cable, set the Ethernet interfaces up on both to use a private local network subnet that doesn't use your wireless, set up Windows file sharing, and dispense with the drive whatsoever.
posted by eschatfische at 6:22 PM on March 16, 2015 [3 favorites]

there exist USB a/b switches, you could alternate access to one external hard drive. Some NAS enclosures might allow usb access and network access simultaneously.
posted by nickggully at 6:22 PM on March 16, 2015

Sounds like you need Network Attached Storage. It's a device which contains hard drive and a CPU and connects to a LAN via ethernet.

Some of them run Linux, but you don't have to care about that part. There will be instructions on how to connect from Windows and from the Mac. (Sometimes you have to run a utility on the computers.)

One thing that's nice about having an NAS is that they often have the ability to run regular automatic backups of your computers if you set them up to do so.

Here's some sold by NewEgg.
posted by Chocolate Pickle at 6:43 PM on March 16, 2015 [2 favorites]

I'd like both of them to be hooked up to the same external drive (or some kind of backup drive), so I can pass files between the two, WITHOUT using the wireless network.

You cannot plug a (USB) drive into two machines at the same time. You can disconnect from one computer and then connect to the second, however.

Since you do not want to use a (wireless) network connection to the drive, this rules out the use of NAS drives.

If you use an external drive, use a disk format like FAT to be able to read from and write to the drive from both computers. Using other formats will make them inaccessible or read-only from one computer, without using third-party software.
posted by a lungful of dragon at 6:46 PM on March 16, 2015

ALOD, why can't the OP set up a wired ethernet LAN and connect to an NAS through it?
posted by Chocolate Pickle at 6:51 PM on March 16, 2015 [1 favorite]

An option I have used is to format the external media as NTFS. The Mac can read that as is. For complete two-way potential, install Paragon NTFS for Mac.

I recently had a month of frustration archiving 50 GB files from both OS X 10.10 and Windows 7 systems to 3 TB disks formatted exFAT. I'd get halfway through, and the disks would throw errors that chkdsk on Windows couldn't correct. Forums suggested that possibly fsck_exfat on Mac might do better recovery—but Macs might be the source of the errors in the first place. My solution was to attach the disks to a Windows system and trickle the files over the network, as you said you did not want to do. For only one Mac involved, I would have paid $20 for the Paragon NTFS approach, which worked fine in previous such archiving. There are also no-$ FUSE drivers that let the Mac do NTFS. Though exFAT seems made for archiving, NTFS has journaling and other robustitude and can encrypt the whole disk.
posted by gregoreo at 6:56 PM on March 16, 2015

I think Chocolate Pickle has it.

Just connect the drive to whichever computer is easier (probably the windows PC, if it's a desktop), connect the computers with ethernet, and share the drive. This also means that filesystem issues are irrelevant: pick whichever filesystem the disk host is most happy with.

The downside is that you'd need to have the hosting computer on while using the other.
posted by pompomtom at 7:21 PM on March 16, 2015

Seconding NAS. Synology makes good appliance NAS boxes, by which I mean they have a custom linux OS that lets you access and manage files through a web browser, set access and security...but that's probably overkill-- you're looking at a drive you can mount as a network drive on both your Mac and PC. Synology can also do this, but you may be able to do it cheaper. They use a linux-common file system called ext4, but I use one at work with both the OSX and Windows boots on my Mac-- it's no problem.

I have a Linksys NAS, but it looks like they're out of the NAS business. With mine and those like it, you buy the box cheap and add drives for your own. Whether or not you have to add your own drives will significantly affect the cost, so keep an eye on that. Doing so does mean you can add more storage to it later.

NAS boxes, especially those with multiple drives, may let you mount the drives separately or together--this way you could have a separate backup drive or time machine drive in addition to storage.

Too much to deal with? Get a USB drive and leave it on your PC. Share it to your network, and then you can mount it on your Mac for file transfer.
posted by Sunburnt at 8:58 PM on March 16, 2015

It's not really necessary to go through the trouble of setting up an NAS -- but yeah, a wired network would be easier if you want to be able to access the drive without moving it around. You can share the drive from the Windows box and the Mac will be able to access it just fine. You won't even have to format it exFAT to do this -- plain old NTFS will do.

In my experience exFAT can be kinda finicky on drives that are often swapped around anyways. If you're not careful to eject the disk every time, you'll end up with a dirty filesystem and will have to go through a disk repair cycle before being able to use it again. Not really harmful, but pretty annoying.

If your goal is to back up the Mac, I feel obliged to point out that you can set up Crashplan to backup the Mac to the Windows box (whenever it's on), and from there backup to the Crashplan cloud service. You can even do this without a Crashplan subscription (using the client on both computers) if you skip the cloud part.
posted by neckro23 at 10:45 PM on March 16, 2015 [1 favorite]

Just for the sake of completeness - you really need a disk drive in the middle between the two devices? Because there are special 'cables' that can be used for system to system file transfer via USB.

But if you want to put a disk in the middle - I've actually done this with a Synology NAS that has a dual Gigabit Ethernet port (not all Synology models offer this).

It wasn't as straightforward as it seems, though, because the two ports are primarily intended for Link Aggregation (ie, dumping data out onto the network twice as fast). What you will probably need to do is bridge the ports - and at the time I was messing around with this stuff, that was not something that Synology DSM would do for you (and I don't believe this has changed).

So to set up the bridge, you need to become root in a command shell on the NAS and do something along the lines of this:

insmod /lib/modules/stp.ko
insmod /lib/modules/bridge.ko
brctl addbr br0
brctl stp br0 off
brctl addif br0 eth0
brctl addif br0 eth1
brctl show
ifconfig eth0 promisc up
ifconfig eth1 promisc up
ifconfig br0 netmask up

where is the NAS device. Note that I'm offering this as an untested example of the kind of thing you'd need to do, and I disclaim all responsibility if you destroy your network messing around with this stuff without knowing enough about it. If someone who is a real *nix / networking whiz wants to point out flaws in the above, I'm totally okay with it.
posted by doctor tough love at 11:25 AM on March 17, 2015

Another random vote for a NAS device. Synlogies are fine, and the cheapest one on newegg will do what you want. QNAP also makes decent NASes. I wouldn't buy a cheap buffalo or some other $60 thing.

Your router may already have a USB port. Nearly all routers, included ISP supplied modem+router combos have this feature now. It's likely slow, with generally shitty performance, but this is just for backups so who cares. Start a copy(or schedule one with whatever backup software you want to use) and go to bed. The solution might just be to format the drive, plug it in to your existing router, and mount it on both machines then do that.

Also another "fuck exfat" vote. I've spent over 48 hours waiting for testdisk to recover my entire music collection when i was in the process of upgrading machines and selling my old one because of it randomly corrupting itself.

I have utterly given on manually plug it in and backup type solutions for home backups. I get a whining warning reminder on my macbook every day like "OMFG YOU HAVENT BACKED UP IN 250 DAYS ARE YOU CRAZY?". And this is because i'd have to go get the drive, find its power brick, lug it over to the coffee table and let it run for an hour. If it's on the network, it can be backing up while you're using it without you even caring or realizing.

It's sort of a "the best camera is the one you have with you" situation that makes network backups superior.

Also a note that the only real backup is one you can recover. A week or so after you start using whatever solution you choose, attempt to write all the files back to the machine in a dummy folder(if you have space) and verify that they're intact and what you expect. Even the "pros" like me fail at this sometimes, and i ended up royally fucked when i accidentally hosed a VERY important folder of project files on my home machine, attempted to recover my backup, and only got maybe 2/3rds of it back. Much screaming and swearing and crying ensued, followed by drinking and phone calls of "hey guess what's missing!". Don't be me. Test your backups after you switch to a new solution, storage device, and just like every couple months in general even if everything seems perfect.

Also never ever ever trust apple time machine as your sole backup solution for a machine with important files. Ever. No matter what it's writing the backups to(i see this one like the harry potter "don't trust anything that thinks when you cant see where it keeps its brain" at this point)
posted by emptythought at 4:48 PM on March 17, 2015

Response by poster: Thanks for the answers, all!

"Just for the sake of completeness - you really need a disk drive in the middle between the two devices? Because there are special 'cables' that can be used for system to system file transfer via USB."


Actually, a USB cable would be mighty cool and might work just as well! I didn't even know these things existed!
posted by neeta at 11:06 PM on March 17, 2015

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