Hi, On Mon, Sep 02, 2002 at 12:27:35AM +0800, karhong ng wrote: > I have an internal HDD running under RH7.3. I would like to purchse a second HDD(usb external) of same geometry, and use it as a bootable snapshot of the first internal HDD. > > I wish to make a whole disk bootable backup regularly via this method. > Is this feasible ? If the disk is still mounted, then there are basically no guarantees if you try this. You won't get a coherent snapshot of the disk. We've also had bugs in the VFS in the past which triggered if you did huge amounts of parallel IO on the buffer cache while there's page cache activity going on --- I _think_ it's all fixed now but it's not tested all that much. But if your main filesystems are offline (or readonly/idle --- eg. boot into singleuser mode), it should work OK. "Rsync" often works better --- it does a logical copy through the filesystem so it's entirely safe wrt. the VFS, and it is superb at doing incremental copies. Cheers, Stephen
