Re: Null files reloaded :-)

[Chris Wedgwood <cw@xxxxxxxx>]

On Fri, Jul 23, 2004 at 11:32:26AM -0700, David Sparks wrote:

> What happens when an existing file is changed and only the metadata
> is sync'd?

you can see old data

> open existing file
> seek xxx
> write data
> [filesystem brought uncleanly offline]

you see some/none/all of the new data depending on timing

> The real world example is database files.

for a sane database this shouldn't matter as they have code to work
with this

> What happens if a busy mysql database making a lot of inserts has
> the fs brought down uncleanly?

not sure, my guess is 'bad things' unless mysql has a log

> Are sections of the file nulled or is the entire file nulled?

neither


  --cw