Dual boot backup on external HDD.

August 4, 2008 7:34 PM

What's the best way to setup a 500gb external hard drive to backup windows and linux?

I just got a seagate external hard drive for my laptop, which is out of hard disk room. Surprised by the $100 price tag, I splurged and got a 500gb model. So, I would like to set it up to backup my computer, as well as store files.

I dual boot ubuntu linux and windows xp. Should I make two ntfs partitions, and use windows to image backup my current hard drive? Or, should I use FAT32 and use linux to perform the backup? Would there be any complications when backing up ext3 from windows, if it's just a hard drive image? Also, I'd like to use open source programs to do this.

If I go the linux route, and format it with FAT32, are there any disadvantages, or limits on partition size?

Thanks for the help! Oh, and I use linux about 80% of the time, so It would be most handy to backup with linux, if that's the easiest solution.

posted by kraigory to computers & internet (8 comments total)

Are you looking for a full disk image or just backing up your important files? Do you just want a copy of what's currently on your disk, or do you want versioned backups, so you can roll back a week or two?

If all you want is an exact mirror of what you have, it's pretty easy to set up a cron job that runs rsync every night.

Assuming both disks are present and mounted, it'll be something like:
rsync -avh --delete /path/to/localfiles /path/to/externaldrive >>rsyncLog.txt 2>>rsyncErr.txt

(I pipe the output so I can periodically check to make sure things are going smoothly)
posted by chrisamiller at 7:52 PM on August 4, 2008

And in case it wasn't evident, yes, I think it's easier to do from linux side
posted by chrisamiller at 7:53 PM on August 4, 2008

I'm pretty sure just a blunt disk image would be fine. I don't get myself into enough trouble to need versioned backups, i'm more worried about my hard disk failing, or just totally screwing everything up.

Are there any partition issues I should consider?
posted by kraigory at 8:07 PM on August 4, 2008

I seem to recall (and it makes logical sense to me right now) that a FAT32 filesystem will 'lose' the permissions from Linux. Thus you should try to 'match' filesystems—FAT32 for Windows (NTFS is fine too), and ext3 (or whatever you use) for Linux backups. (And you really want to be root when running the backup, to preserve permissions.)

However, don't make things so complicated that you end up not using it: if you do the whole thing as FAT32 and eventually need to recover your Linux system, you could probably get back on your feet pretty quickly with a new installation, and then copying your home directory and using chmod/chown to fix permissions.

chrisamiller gives good advice on rsync, though I'd add that you should check out the man page, especially the --ignore-directory (I think? I'm in Windows) option, so you don't waste time backing up /dev and /proc, or anything else that makes absolutely no sense to backup.

Oh, and let my late-night screwup from a long time ago be a warning to you: unless you're really, really sure what you're doing, and you're doing something really weird with a backup from 1992, and you enjoy all your files to be in the 8.3 format (remember DOCUME~1.doc and the like?) you want fat32, not vfat, as the filesystem type.
posted by fogster at 8:21 PM on August 4, 2008

I use Microsoft's SyncToy for backups to my NAS (essentially an external drive), even though the files are on my Linux file server (which is just a regular used Dell, with Ubuntu installed, but assigned to the task). I also have a cron job on said file server for a daily backup of important files to an attached flash drive, it uses rsync if memory serves. If you want to pursue that route, there's info if you Google for it. Lifehacker had an article at some point related to it.

Personally, I gave up on dual boot, got an extra expired-lease box from work, so that I have an XP box (which I use primarily), an Ubuntu box (not being used, but I was working in a Linux environment so wanted to have it on hand, and as a contingency plan against Vista), the Ubuntu file server, and a cheap NAS for full backups, in addition to the flash drive for daily backup of important files. Some stuff is also mirrored on an encrypted volume on my laptop, using TrueCrypt.

Not sure that answers any of the question, but maybe someone will find something useful out of it.
posted by hungrysquirrels at 8:34 PM on August 4, 2008

I've done quite a few backups myself, and this nifty little device has made it a little easier. It's a thermaltake usb dock for SATA drives. Just plop it in and you're ready to do backups with whatever program you want.

Personally, I got mine at mwave for about 35 bucks.
posted by Zeker at 8:46 PM on August 4, 2008

I'd use ext3, because you can find Windows drivers for it quite easily, and avoid the various hassles of FAT (permissions and large files, mostly). I'll add that I'm not used to the newfangled linuxes which do ntfs.. and am yet to be trusting that.
posted by pompomtom at 9:20 PM on August 4, 2008

I agree that I'd probably use ext3. You'll keep your linux permissions that way, and windows reads ext3 just fine with something like ths driver installed.

second what fogster says about excluding certain directories. It may be helpful to use an exclude file if you have too many to list in the command.

I usually just back up /home/, /etc/, and /opt/ (because I store a few programs/config files there).
posted by chrisamiller at 10:37 PM on August 4, 2008