Files get broken

[Sebastian Pahlke]

Hello,

my FreeBSD 5.4 release system makes some annoying things which I don't
understand. I use gmirror to mirror two IDE discs which seems to work
without problems until now.
I also use gbde to encrypt one data partition, but this partition seems NOT 
to
be affected for now, so I guess it's not a gbde related problem.

Some day's ago I would modify /boot/loader.conf (on /dev/mirror/gm0s1a).
As I opened the file in vi I saw just a line full of garbage. I was
confused a little bit, then I decided to rewrite the file
from (my human) memory, fortunately there were just two lines.

Now, some days later, I found another file which was corrupted.
It was a copy of /etc/fstab named /etc/fstab.orig (on /dev/mirror/gm0s1a).
If I open the file I see, again, only garbage:

\x868N^@^@;\x86<N^@^@u^O\xffu\xf4\xe8c^H^@^@\x83\xc4^D\xebj\x89\xf6\x8b\x9e
8N^@^@\x8dC^A\x89\x868N^@^@\x8bE\xf4\x8b@^\\xc6@^B \xc7@^D@^@^@^@\x89\xda\x
c1\xea^P\x88P^P\x89\xda\xc1\xea^X\x88P^Q\xc6@^R^@\xc6@^S^^\xc6@^U^Uf\x89X^V
\xffu\xf4\xe8\xb4^C^@^@\x83\xc4^D\x85\xc0t^YSh^\xe3\x80\xc0\xff6\xe8\xdc,^M
^@\xffu\xf4\xe8\xf8^G^@^@\x83\xc4^P\x90\x8de\xf8[^\xc9\xc3\x90U\x89\xe5WVS\
x8b]^H\x8b{^H\x8bs(f\x83{^T^@u^VVW\xe8#^@^@^@h`\xa2\x87\xc0V\xe8\xf0^^K^@\x
83\xc4^P\x90S\xe8\xba^G^@^@W\xe8|\xfe\xff\xff\x8de\xf4[^_\xc9\xc3U\x89\xe5W
VS\x83\xec^H\x8bu^L\x8d^^X\x83~^H^\u'^O\xb6C^B\x83\xe0^O\x83\xf8        u^[
\x80{^L^@y^U^O\xb6S^L\x80\xe2^?\xc1\xe2^H^O\xb6C^M^A\xc2\xeb^F\x8dv^@\x8bV^
HRh^@\xa8\x85\xc0

Can anyone imagine whats going on? What does my system?
I'm scared because the FreeBSD box is my fileserver storing my whole
media library. Many thanks for help in advance!

greetings,

Sebastian Pahlke