OT: XFS eats Files, was: Re: [Samba] Possible Filesystem Corruption with Samba 3.0.25a (with XFS and LVM)

[Rashkae]

Asier Baranguán wrote:
> Jerome Haltom escribió:
> 
>> XFS eats files. Did you lose power or did your system crash? XFS is very
>> good at losing files.
> 
> Hmmm... I have two samba PDC running in a very faulty electrical 
> connection, with power failures each week and XFS never hit/lose a file.
> 

This is a type of scenario where you really *don't* want to use XFS, 
because it *will* eat your files.

Not by mysterious file system destroying corruption however.  The issue 
is that XFS does not write Metadata updates in an ordered fashion.. That 
means a file's meta data can be updated before the data is flushed to 
disk.  This will cause parts of files being written to be replace by 
binary nulls.  It is especially problematic for software that copies a 
new file over an existing file without first doing an fsync to ascertain 
that the new file is flushed to disk before unlinking the old one.  (KDE 
has been known to destroy it's configuration files this way, and dpgk on 
Debian systems can pretty much destroy the system.)