Slower performance with ext4

Rashkae ubuntu at
Mon Nov 2 11:57:24 UTC 2009

Christopher Chan wrote:
> Rashkae wrote:
>>> Journaling only for metadata is not 'as much journaling as any other 
>>> canditates.' You cannot say metadata journaling only as equivalent to 
>>> the data and metadata journaling that is possible with ext3. XFS's 
>>> journaling only provides filesystem metadata consistency which is why 
>>> you get files full of NULLs after a crash/power out. MTAs rely on fsync 
>>> calls and how a filesystem behaves in regards to fsync requests is the 
>>> real determiner of whether there is a data guarantee or not. XFS does 
>>> not provide data guarantee. I
>> This is completely false,, XFS gives as much data guarantee as the other
>> filesystems in respects to an fsync.  The reason files can have Null
>> bytes appended to them in XFS is because XFS, unlike ext3, will commit
>> meta data changes out of order from the data actually being written to
>> disk, but this has nothing to do with fsync, which works as intended.
> Wake up call.

I was going to reply to this, but your not even trying.  That had
nothing to do with XFS or filesystem features at all, and I'm well aware
of the potential problems with hard drive write cache... doesn't mean
anything to this discussion.

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