Linux Guru/ Partition Magician Needed

January 4, 2009 5:31 PM

So i partitioned my pocket 320gig USB drive and installed the lastest ubuntu. My intent was to use it like a live CD to virus scan windows XP worksations (to avoid imaging). Odd thing though, I can not access any data on this drive when running WinXP. in windows, it tells me that the drive isn't formatted. I checked the drive and see the Ubuntu partition, the original partition and a small 1gig partition I assume was created during the Ubuntu install. Grub loads when I restart the machine and boot from USB and Ubuntu runs fine. Is my data irrevocably lost? I was thinking of deleting the MBR, but I figure that'd just make the drive useless. ideas?
posted by Davaal to computers & internet (14 comments total)

http://www.google.com/search?q=xp+ext3
posted by devbrain at 5:41 PM on January 4

how did you partition it? if it had data on it and you weren't very careful when you repartitioned (i.e., using gparted in Ubuntu to resize the existing partition), you probably erased all the data. by default, repartitioning is destructive.
posted by mrg at 5:42 PM on January 4

windows XP cannot read EXT3 filesystems natively.

deleting the MBR would render the drive unbootable, as the MBR is where grub resides.

if you want to read the disk from windows, you'll need a filesystem driver like this (no clue if that's a good one or not, thought it is freeware)
posted by namewithoutwords at 5:43 PM on January 4

What devbrain is trying to tell you is that by default, when running windows xp (or any other windows), the type of partition (filesystem) that linux creates won't be visible / accessible. Therefore you'll need some application that can do this -- "linux reader" is one of them.

This is a matter of incompatibility of various filesystems. Many operating systems have their own type of filesystem and they're typically not cross compatible.
posted by ezekieldas at 5:46 PM on January 4

Try installing Ubuntu on an NTFS partition instead of ext3. Windows will be happy with that.

(may require some screwing around; I'm not sure if the Ubuntu installer will give you a user-friendly way to do it, but it is possible)
posted by qxntpqbbbqxl at 5:51 PM on January 4

Are you primarily concerned about data loss? When you boot into Ubuntu can't you see the data on the other partitions? On my partitioned computer the linux side has no trouble reading the data on the windows side.

If you can see the data than just boot into linux and copy the data to CD/DVD.
posted by oddman at 5:51 PM on January 4

Try this if you don't want to go with a driver-based solution.

You might think about repartioning that drive to include a small ext3 partition just for the Ubuntu install and leave the rest as NTFS for storing files that you'd like to be able to access from either OS. I believe GParted can handle a repartition without destroying the data on the drive, but you'd do well to back up any important data before trying it. Leave the small partition alone; from how you describe it, I assume it's the Linux swap partition.
posted by sinfony at 5:55 PM on January 4

This is the expected behaviour, and isn't necessarily a problem unless you for some reason wanted to be able to put files onto the Ubuntu partition from within Windows. I've heard that NTFS support is better of late, but rather than following the advice qxntpqbbbqxl gives of re-installing Ubuntu on an NTFS partition, I'd suggest simply making a small "data drop-off" NTFS partition of, say, 200MB, that you'll solely use to transfer files back and forth between the systems.

Now, if you do not need to put files on the Ubuntu system from within windows, simply do nothing and keep it as-is.
posted by odinsdream at 6:53 PM on January 4

So you have three partitions on the disk: one that you used to be able to read in Windows and two that Ubuntu created? Windows should still be able to read your original partition. Windows won't be able to read Ubuntu's larger partition unless you install a driver for the ext3 filesystem that Ubuntu uses. There is nothing to read in the smaller partition Ubuntu created; it's the equivalent of a pagefile in Windows.
posted by PueExMachina at 8:00 PM on January 4

I'd give Linux a 20 ext3 gig partition or so to work in, & the rest for holding work files - fat32, probably.
posted by Pronoiac at 8:47 PM on January 4

Do not install ubuntu on an ntfs partition: ntfs is a patent/trade secret of microsoft and last I knew even the latest ubuntu drivers for ntfs would occasionally corrupt files or bork the entire filesystem, and ntfs lacks file system features that ubuntu kind of needs, like unix style symlinks.
posted by idiopath at 9:47 PM on January 4

Windows will occasionally refuse to work with any partition except the first (or the boot partition, if there is one) on an external drive (yes, this does suck deeply and no, there is no good rationale for it). So if the boot partition is your ext3 Ubuntu partition, Windows will probably not mount any of them.

You should be able to work around this by making the first partition the boot partition, formatting it FAT32, and telling the Ubuntu installer to mount it as /boot. Ubuntu will put a handful of files in the root directory, and create a grub subdirectory with some more stuff in it. Windows should see all those. Leave them alone (or use Windows to set the Hidden and System attributes on all of them if you want - Ubuntu won't care) and you should be able to fill the rest of it with anything you want.

Ubuntu doesn't need symlinks inside /boot, so FAT32's lack of support for those is not a showstopper.
posted by flabdablet at 11:24 PM on January 4

You can view and read (copy to Windows) files on that partition by using the Windows program Explore2fs

However, I don't believe you'd be able to write to the drive with this program.
posted by ijoyner at 10:02 AM on January 5

On re-reading your question, it seems you have some concern about the continued existence of files that already existed on your first partition before you did the Ubuntu install. They should all still be there, and they should even be accessible from Ubuntu (you might need to hand-mount the partition if you didn't tell the Ubuntu installer to automount it for you at startup); if I've diagnosed this correctly, it will just be Windows that's refusing to look at them.

If you turn off the Bootable flag on the Ubuntu partition, I expect that Windows will once more see the first (NTFS) partition as The Partition, and let you get at your stuff from Windows. Doing that would break the standard DOS primary bootstrap that Windows puts into the master boot record (the very first hard disk block, which also includes the partition table) but I don't think Grub cares whether or not the Bootable flag is set on the partition it's been told to read its menu from.
posted by flabdablet at 5:50 PM on January 5