Re: [libreoffice-users] Re: File corruption on OSX and LO 4252

2014-07-16 9:42 GMT+02:00 Alexander Thurgood <alex.thurgood@gmail.com>:

> I was also always sceptical of reading/writing directly from/to external
> storage, but this issue had never occurred in any of the preceding 3.x
> or 4.1 versions of LO on OSX (or in any other version of
> StarOffice/OOo/LO/AOO/NeoOffice that I have had). So, I was naturally
> caught "unawares" as they say. After many hundreds of hours of using
> previous iterations of LO with external storage, one certainly does not
> expect it to behave in a contrary fashion in an allegedly "stable" release.

​This is not really an answer regarding LO, but a general observation on
using external storage that might be pertinent in your case.

I use external USB drives to store most of my media files (pictures and
videos, with some audio files). That imply a lot of files, with relatively
large size. In this setup, I never had a problem with file corruption.
Except for that one time, which happened exactly as I was doing a backup
copy of the whole drive. Every single files where corrupted. When the copy
ended, all files where there. They all had the correct size, but all of
them where invalid. Some video played for a second, then stopped
encountering invalid content, pictures where completely unrecoverable, you
get the idea.
After that, I tried to find the culprit: it was not the OS (windows 7), as
other drives, and these two drives at other time, worked perfectly fine. It
was not the copy software either (teracopy at the time). The USB drives
themselves didn't report any error, and worked fine afterward (they are
still fine today). Turns out, a faulty USB hub can cause silent copy error:
the software, whatever it is, will see the write operation succeed, when
the content on the drive is garbage.

Long story short: a "passive" USB hub silently corrupted ~1TB of data.

Now, let's go back to your issue. The code for writting files (in
LibreOffice or any other software) is the least difficult part to port from
system to system. There is litteraly nothing to do, as various libraries
(including the standard C library) provide the necessary functions. For
most piece of software, there is also no difference at all in writing to an
internal hard-drive, or to an external one.

I'm not saying that the issue doesn't exist, mind you. Bugs exists, and
weird interactions can always happen. But since the "file writting" part is
probably the simplest thing in the whole program, it would be very
interesting to check if LO is really the culprit. The fact that it only
happened those two times with LO is not conclusive: if it is indeed caused
by external causes, it could have gone unnoticed if, for example, you
weren't manipulating other files on the drive at the time.

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