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Journal cyranoVR's Journal: Linux Undelete...NOT! 19

Journal by cyranoVR

It turns out that because my linux system uses ext3, the utility debugfs and all the freely available programs that automate it are useless.

See, in order to add journaling, Red Hat changed the filesystem code so that it "zeroes out" the inode information whenever a file is deleted. I discovered that Red Hat released a whitepaper about ext3. Nowhere do they mention that ext3 renders debugfs lsdel useless, even though this behavior is by design. I am dumbfounded that red hat chose not to mention this "minor detail" in their whitepaper. A few searches on google has revealed that I am not the only person to be rudely suprised by this difference between ext2 and ext3 (imagine what it's like for people that are used to using ext2).

Anyway, I realized that even if I could recover the deleted files - say with a utility like lde (linux disk editor), I would have to spend hours and hours cat'ing them back together. Most were mp3's and jpgs 500k - 3 MB in length, so obviously this is more trouble than it's worth. Seems data recovery in Linux is only practical when you want to recover text files (i.e. that perl script you accidentally deleted). Most of the messageboard posting talk about grep'ing raw blocks on the disk in order to find the lost file. Ugh.

So, I have resigned myself to the fact that I will not get my files back from GUNNM's dark abyss. However, since my files were originally stored on my T20 and Aptiva, I figure I can recover them from there instead. I have successfully recovered from my Aptiva before (after the last time I had to reformat it), so I know it's possible. I will install the recovery software to the new share drive (this time mapped to /home/share/, dammit) and recover the files to the same. Since I have not installed any large files to the aptiva or T20 since moving the images and mp3s off them, I figure at least some of the files must still be on there!

Meanwhile, I have a new TODO list for GUNNM:

1) Remount the filesystem as ext2

I am not sure how to do this, as online documentation says "simply unmount and remount as ext2!" but I am sure it is not that easy - or even if it is, I will screw something up. What if I unmount and can't remount? Should I do it from "single user mode" whatever that is?

2) Re-partition

I would like the sharedrive to be mounted to a separate partition. I thought that redhat came with a program called "Disk Druid" but apparently you can only run this at install time? Antifreeze suggested that I use parted - but again, I am pretty sure that if I start screwing with command-line utilities, I will ruin the system.

* * *

I was realy angry about this, but MrsVR pointed out that mp3's and jpg pictures are easily replaceable, so it's not worth getting angry about.

But the real thing I feel angry about is how stupid I was. First I installed using ext3 without doing full research on it's limitations (I just accepted the default install). Then I made the dumb fucking mistake mapping my Samba share to /tmp, where everything was SURE to get deleted.

What the fuck is my problem.

I think the conclusion is that I should stay the fuck away from systems administration as a career - or even as a hobby for that matter. It makes my brain glaze over, every system I touch turns to shit, and I lack common sense.

I guess it is time to try to focus on java again. I have wasted enough time with this shit. Tomorrow I will go to Staples, buy some sort of data recovery program, get the files off my windows machine, and move on with my life.

* * *

If anybody else has any "I fucked up my system and lost everything" stories that they don't mind sharing, please post.

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Linux Undelete...NOT! More

Linux Undelete...NOT!

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  • 3. Backup. Often.
    • 3. Backup. Often.

      All my important files - i.e. tax returns, drivers, etc etc are backed up to CD-R media. MrsVR makes sure of that (she is the sensible one after all).

      The ironic thing is that GUNNM is going to be my backup. I plan to use microsoft's built in backup tools to backup my other pc's regularly to GUNNM's massive 120 GB hd (my T20 only has 5 Gigs of data and my Aptiva 6 GB).

      I don't really want to buy a tape backup solution, but it looks like that's where I am heading. I will backup to GUNNM
      • 4. ???
        5. Profit!
      • I don't really want to buy a tape backup solution, but it looks like that's where I am heading. I will backup to GUNNM and then doubly backup with a tape drive. Only problem is: are there any good home tape drives on the market that run on linux?

        I would probably get some sort of DVD writer for backup. Any tape format I know of that is worth spit and has enough capacity to handle a 120 gig drive tends to be expensive (SDLT, LTO, AIT, or the IBM/StorageTek format).

        There are some cheap secondhand Exabyte (8
        • Comment removed based on user account deletion
          • Well, imho i tell most people to use ext3, but if your concerned about undeleting, use ext2. Yes, you might have data unsynced for 30 sec in case of powerloss, you have a long fsck, but you can undelete. If you box doesn't have random power losses or shuts down uncleanly often, then it doens't really matter too much.

            for cyranoVR, ext2 should be fine.

            Well I don't like long fscks. I've been burned enough by non-journaling filesystems on other UNIXes to be worried about what happens with sudden power loss.
  • Comment removed based on user account deletion
    • No, your just learning

      So far most of your problems do not seem to me to be that bad.

      The attitude that I frequently encounter in the IT world is "everything is obvious, if you screwed up it is because you are stupid."

      At work, my manager at work is always smuggly chuckling to himself whenever I (or a user, for that matter) has a problem like this - lost files or whatever.

      I'll ask him a question like you can run a Windows partition on the AS/400 and his answer is a smug "Of course! Heh-heh-heh." No, no
      • Comment removed based on user account deletion
        • Let us know how the recovery comes about and if you have any other issues, just ask.

          Well, I am resigned to the fact that I can't get anything back due to the size of the files and ext3's limitations. Still, I will change the fstab to ext2 and then see if I can undelete some files.

          Today MrsVR and I went to staples and bought a utilities program from windows that includes EasyRecovery Lite. So we will see how that goes.
      • In the end, he has taught me that I don't know shit and I shouldn't bother trying to learn because I don't have a computer science degree (he keeps reminding me that I don't really know what I'm doing because I lack said degree).

        CS majors make horrible system administrators usually. I doubt most people here working as sysadmins have CS degrees. Heck I'd bet many programmers here don't have a CS degree.
        • My manager is always lecturing about "logical" files vs. "physical" files. At the end of the lecture he usually says something to the effect of "and that's what you're missing out on because you don't have a CS background."

          Don't get me wrong: I've learned a lot about programming from him - but when it comes to systems, I get the sense that a computer science degree doesn't make much of a difference.
          • My manager is always lecturing about "logical" files vs. "physical" files. At the end of the lecture he usually says something to the effect of "and that's what you're missing out on because you don't have a CS background."

            Logical vs. Physical devices or partitions maybe but it sounds to me like your manager is blowing smoke up your ass.

            as for partitions or devices the difference between logical and physical isn't THAT hard to grasp and certainly doesn't need a CS degree.

            Your manager sounds like he may
  • Sorry to hear about the data loss. That is something that the Linux distros really need to work on. I have my own tale of data loss. I lost 14 Gigs of MP3s I had ripped over a three month period and some fairly valuable saved game files from Riven that had been saved over the samba share that I was using from a Windows box. What happened was that my "file server" had an old enough BIOS that it couldn't use a drive larger than 2 Gigs. I had just bought a 17 Gig drive (this was 1998). To my surprise, it
    • Comment removed based on user account deletion
      • Yeah. I don't understand the whole underpinnings of the mechanism, but I used "file allocation table" to try and describe what it is that was gone. Everything I read pretty much explained that my original /dev/hda1 held the table of contents for my /dev/hdb1. So with the original drive being gone for good, so was the table of contents. When I tried running an fsck on my /dev/hdb1 (the /mnt/mp3 filesystem), it said there was no filesystem or partition on the drive on the drive. But I did manage to use a

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