hi, I was wondering if there's a way to safely disconnect a usb device from computer, I ask this because in windows when you disconnect a usb pen with the safe removal, the pen light then turns off, while I tried removing the pen with solaris and the light was still on ?

as long as nothing is mounted you are good to pull the drive.

it's all about disk cacheing.
the "safe removal" function in windows just fluches the cache and mark the file system as clean.
the same as an unmount in unix.

as for the light, windows has a driver that understand the light, and can turn it off, in unix you dont have such a nice driver.
in some versions of linux the light should turn off.

That nice light only works in Windows XP, generally. Vista and 7 no longer do this for my flash drives.