Re: data loss with delayed allocaton

[Eric Sandeen <sandeen@xxxxxxx>]

Fong Vang wrote:
> I just read the following article:
> http://madpenguin.org/cms/index.php/?m=show&opt=printable&id=6045
>
> Near the end, this line caught my attention: "the delay means that
> while a crash will not destroy FS, it might result in significant loss
> of data that has not yet been written to the disc."

Just before that he says "One thing some might find disturbing about the file 
system, is delayed allocation."  So he's talking about delayed allocation here.

But delaying the actual allocation of blocks for data is not the same as 
delaying the flushing of the data into those blocks.

File data flushing is controlled by bdflush as with other filesystems.  Blocks 
are allocated at flush time - this is the "delay" part, and affects when blocks 
get allocated, not when data is flushed.

The article also says that disks have 512k sectors ;-)  So don't believe 
everything you read....

-Eric