How can one monitor what part of big file changed

Question

Is there solution for Linux kernel-3.0 (or later) that allows one to get notifications similar to inotify describing particular segment of file that was changed?

There was fschange patch for up to kernel-2.6.21. Is there any up to date solution available? Is recent fanotify able to provide the functionality?

score 0 · Answer 1 · answered May 07 '13 at 01:44

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IMO... forget using inotify unless "the pretty" is important. Other than that, you can setup a cronjob with a script doing a diff or using FIND with the MTIME option.

answered May 07 '13 at 01:44

Boyd Ako

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score 0 · Answer 2 · answered Oct 22 '11 at 08:10

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Not that I know of, but there is a way to sort of hack the functionality by using the file change notification as an indicator to read the on disk format of the file system an examine the internal file system block allocation tables to learn whats changed.

It's tricky to do, suffers from race conditions and probably a bad idea, but if you must and coding an fschange on top of 3.0 is not an option for you, it might be the way to go.

answered Oct 22 '11 at 08:10

gby

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Aren't "internal file system block allocation tables" different from filesystem to filesystem? – myroslav Oct 22 '11 at 08:24
Yes, they are. the solution would have to be coded for each file system. – gby Oct 22 '11 at 17:40
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Porting fschange appears to be smaller effort. – myroslav Oct 24 '11 at 06:24

How can one monitor what part of big file changed

2 Answers2