ext3, data_writeback and your fear of lost data

For the past two years or so, I’ve been manually adjusting Ubuntu’s default ext3 filesystem to use the data_writeback flag because it lends a considerable degree of peppiness to an otherwise sluggard of a default system. Over time I dropped journalling file systems altogether, because I didn’t see wasting processor cycles or I/O times — particularly on old machines — on keeping track of which files were changed, when, and how.

And I can honestly say, with 100 percent veracity, my hand on the Bible or the Torah or the Koran or whatever book you think holy, that I have never suffered any data loss I could directly trace to that tweak, or that filesystem.

In fact, the only time I had I crapped out installation that I could be fairly certain was the fault of the filesystem, I was using XFS. And that was a looong time ago.

So I’m going to go out on a limb, and I’m going to continue to endorse it. Even if …

  1. this post,
  2. this mailing list entry, and
  3. the sqlite Web site

all mention the possibility of losing data in Firefox while using ext3 with the data_writeback flag. And I’m even going to turn up my nose at some of the comments on this otherwise admirable list of Ubuntu tweaks, which suggest noatime is a no-no too.

I’m not a Linux expert. I don’t hold any computer science degrees and I’ve never held a job as a sysadmin. There are a lot of things I don’t know, and there are plenty of times when I’m just plain wrong.

But I am a trained journalist. And so I’m not going to speak outside of any facts — and in this case, those facts are my personal, immediate experiences. I don’t endorse or suggest anything I haven’t tried myself, and I don’t grasp at blog posts, or random anonymous experts, or armchair quarterbacks, over my own history with one part of Linux or another. I know what works for me, and what hasn’t, and that’s how I judge.

So again, I’m going to continue to suggest ext3 and data_writeback, or ext2 with noatime, or both and all three at once. You can wave your degrees or your resume or send digg links if you feel that’s necessary, but until my trusty Inspiron comes to a screeching halt with filesystem error messages, I’m going to continue to blithely wander along this path.

You are free to join me, or if you prefer, find your own direction. That’s what makes Linux great.

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6 thoughts on “ext3, data_writeback and your fear of lost data

  1. Sir_Sid

    Hey if you back up the important stuff there is really no reason why you cant do this. But at the same time, there is always that risk that some cannot take.
    I might do this myself. I save all my stuff directly into my drop box folder so its always synced off the machine.

    Reply
  2. K.Mandla Post author

    I agree. I keep anything important (backup configuration files, project folders, etc.) on a separate drive anyway, so even if some bizarre cataclysm befalls my system drive, the other stuff should be safe.

    The irony of that is that I use ext2 with noatime on that backup drive. :lol:

    Reply
  3. Paul

    “but until my trusty Inspiron comes to a screeching halt with filesystem error messages”

    But it will, it will. It’s only a matter of time.

    I speak from the opposite perspective, someone who has suffered data loss.

    That’s why I’ve migrated everything, even /tmp, to ext3.

    Reply
  4. n7

    You know what? I’m doing this also since years, but i didn’t trust it. Then i tested this sort of setup in a very unscientific way: I literally pulled the plug about three dozen times. I did this also under stress, i.e. having a few applications with opened files, OpenOffice, PDFreader, a few dozen running torrents, MP3s playing and so an, all i could think of. Then i checked the FS from different Live-CDs with different kernels and fstools. No errors at all. Maybe it was luck, maybe a combination of hardware and drivers which fits well together, maybe one shouldn’t do that on a very busy server, whatever. For my own personal uses i had no stress with this. Never.

    Reply
  5. h4mx0r

    Boot it up then pull the power plug a few times and it will. Thing is you got a smart power kill setup going with your hd. Try killing the power in new and inventive ways and you’ll experience data loss like all the rest. I was just like you when I first started using linux wanting to use ext2, but damn that really was a waste of time. And its mostly grub that seems to be destroyed usually, I suspect because its at a certain well worn end of the disc and read every boot while never being edited.

    Reply
  6. Pingback: Ubuntu 10.04 filesystems and boot times « Motho ke motho ka botho

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