hello:
I have a dm368 embedded system board as DVR, and it's OS is Linux.
I make a testing and the steps are as below:
[1]. I use this DVR system to record video files on a 160G HD, then I type "df -h <mounted path>" to check the usage of this HD, and the terminal shows:
Filesystem Size Used Available Use% Mounted on
/dev/ssd 149.0G 50.5G 99.4G 32% /mnt/ssd
that seems right!
[2]. I remove the HD, and then connect it to a WindowsXP PC, then I delete all the video files(50GB). the usage of HD on Win is about 0%...that's no problem!
[3]. connect the HD back to DVR, after mounted, I type "df" command as [1] to check the usage, however it shows:
Filesystem Size Used Available Use% Mounted on
/dev/ssd 149.0G 50.5G 99.4G 32% /mnt/ssd
(I expect that the usage should close to 0%)
it seems not to be changed!~ I have remount many times and change mounting path, even reboot the DVR, but it's no work! I also check the video files deleted on Win, they are all exist, but couldn't playback! I have no idea!
~~~ I repeat step[1][2] ,but connect HD to a Linux PC, after the deletion, then "df" shows:
Filesystem Size Used Available Use% Mounted on
/dev/ssd 149.0G 0.5G 148.4G 0% /mnt/ssd
it shows the right HD info on terminal of Linux PC. then I connect HD to embeddedLinux(DVR), it also show the right HD info.
my experiment 3 is done the HD deletion on WinXP PC and check the HD usage by typing "df" on Linux PC, and the Linux PC shows right HD info.
my conclusion is Linux PC will get right HD info. whatever the operating of HD is on Win or Linux, but the embedded Linux~~~
now I hope to done the deletion on WinXP PC and check HD usage on DVR(embedded Linux) will also get the right HD info. just like Linux PC... How should I do???
any advice will be very appreciate~
thank you!!!