adilger at sun.com
Wed Feb 24 21:37:26 UTC 2010
On 2010-02-24, at 01:49, Schrittesser, Florian wrote:
> i wanted to ask you all about the exact overwrite mechanism used in
> ext3; is the information in the datablocks overwritten or written to
> a new location and the information in the referring inode is
> changed? Is it depending on the application used (and the functions
> it calls) or independent from that?
> Please don't hesitate to go into further details and thanks for your
It depends on what your application is doing. If it is opening the
file with open(O_TRUNC) then writing it, the new data is written to
wherever it is allocated. If O_TRUNC is not used, then the data is
written into the same blocks as were previously allocated to the file.
Sr. Staff Engineer, Lustre Group
Sun Microsystems of Canada, Inc.
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