Hi, Hans wrote: > I put a harddrive with linux with a native installed linux (native means, > the harddrive was built-in) in an usb-case and could boot from it. > [...] > 1. Is this is normal standard behaviour and can this be confirmed?
This depends on the settings of your computers firmware (Legacy BIOS or EFI). But technically the bus type should not make much difference as long as the involved firmware and the software on the disk can operate it. > 2. Does such a booted linux behave as lin ux from built-in harddrive or is > there something I should watch? One difference will probably be the disk name in /dev/disk/by-*. E.g. the names in /dev/disk/by-id usually contain the bus type and differ in their shown device info depending on the bus at which they were detected by the system software. > Question is, will this work or will the upgrade possibly destroy some > configurations, because it is now an USB-drive? Your mileage may vary. Make a backup before trying system admininistration tasks. > If all this is normal standard, what is the technical reason for this? The various busses present the drive to the software as storage device with some kind of bundles of bytes. The lowest software layers unify these device models in a common model with a consequtive list of storage blocks of fixed size on which the higher software layers operate. This way only a limited number of software modules have to be aware of the differences between busses. The vast mojority of software sees only a storage device of a particular size with particular content. > Is this > because the kernel is using initramfs and when this is loaded, it is no > matter, from where it is started? The block storage device model of Linux is already up and running when the kernel runs software from the initramfs. But as with /dev/disk/by-id names, there can be always some expectation in the software or its configuration which is not fulfilled any more after the disk has hopped to another bus type. Have a nice day :) Thomas
