[Btrfs-devel] btrfs on /

[Chris Mason]

On Wed, Feb 06, 2008 at 05:49:35PM +0100, Pär Andersson wrote:
> On Tuesday 05 February 2008 21:36:27 Christian Hesse wrote:
> > now that I have a live CD with btrfs support I decided to give btrfs on
> > root partition a try. I have good backups. ;) Here is what I have to tell
> > so far:
> 
> Here is one more data point. As an experiment I have used btrfs
> on / since 0.11 was released. Initially I believed that it
> wouldn't survive more than a few days, but I was wrong and now I
> must agree that it is quite stable. Great work!
> 
> I have btrfs / on a usb stick, so the old filesystems are still
> safe on the hard drive if btrfs should eat my data.
> 
> I have only found two issues:
> 
> * No ENOSPC handling really sucks when your root file system is
>   on a small usb stick. :-)
> 
> * APT (Debian/Ubuntu package management) crashes when it tries to
>   read its package lists. I have not had time to debug this yet,
>   but a simple "aptitude update" is enough to reproduce the
>   problem:
> 
> root at garbage:~# aptitude update
> -- snip --
> Fetched 3B in 0s (11B/s) 
> Reading package lists... Error!
> E: Unable to determine the file size - fstat (75 Value too large for defined 
> data type)
> E: Can't mmap an empty file
> W: You may want to run apt-get update to correct these problems
> E: Empty package cache
> E: Couldn't rebuild package cache
> root at garbage:~# 

Ah ok, this is probably an underflow of i_blocks.  If you strace it
you'll probably find the offending file.

-chris