2009-04-23 06:01:25

by Nick Dokos

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Subject: Re: 32TB ext4 fsck times

Valerie Aurora Henson <[email protected]> wrote:

> Back to something useful the short term... Was the file system created
> with uninitialized block groups and lazy inode table initialization?
>

Uninit_bg was on but lazy inode table initialization was off. I tried
turning lazy_itable_init on but e2fsck gets tons of errors, starting
with group descriptor checksum errors. Unfortunately, I now get group
descriptor checksum errors even without lazy_itable_init and I 'm not
sure why. So I'm back to debugging mke2fs/e2fsck.

Nick


2009-04-23 15:14:33

by Valerie Aurora

[permalink] [raw]
Subject: Re: 32TB ext4 fsck times

On Thu, Apr 23, 2009 at 02:01:16AM -0400, Nick Dokos wrote:
> Valerie Aurora Henson <[email protected]> wrote:
>
> > Back to something useful the short term... Was the file system created
> > with uninitialized block groups and lazy inode table initialization?
> >
>
> Uninit_bg was on but lazy inode table initialization was off. I tried
> turning lazy_itable_init on but e2fsck gets tons of errors, starting
> with group descriptor checksum errors. Unfortunately, I now get group
> descriptor checksum errors even without lazy_itable_init and I 'm not
> sure why. So I'm back to debugging mke2fs/e2fsck.

I ran into a few heisenbugs when I was working on this, and there's
still that one failing test. I did track down the commit that started
it, it was:

commit de119e26eb2cf041a8365994dc3a32efc080682e
Author: Valerie Aurora Henson <[email protected]>
Date: Tue Feb 3 13:15:19 2009 -0800

e2fsck: Miscellaneous e2fsck-related 64-bit fixes.

With this change, e2fsck runs to completion on a minimal 33-bit file system.

Signed-off-by: Valerie Aurora Henson <[email protected]>
Signed-off-by: "Theodore Ts'o" <[email protected]>

I might take a look at the problem with the block group descriptors
and lazy itables; that was some crazy^Wcomplex code.

-VAL