On 2/28/19 10:04 PM, Jobst Schmalenbach wrote: > On Thu, Feb 28, 2019 at 05:19:49PM +0100, Nicolas Kovacs (info at microlinux.fr) wrote: >> Le 28/02/2019 à 04:12, Jobst Schmalenbach a écrit : >>> I want to lock in the SDA/SDB/SDC for my drives >> >> In short : use UUIDs or labels instead of hardcoding /dev/sdX. > > I **KNOW** how to use UUID's ... this is NOT the reason why I am doing this! > > > I *NEED* the order of the disks to be SDA(1st BIOS drive) SDB(2nd BIOS drive) SDC(3rd BIOS drive) and not SDA (1st BIOS drive) SDB(3rd BIOS drive) SDC (2nd BIOS drive). > > Reason: it stuffs up the use of grub2* utilities leaving behind a bunch of error messages. > The SDA (1st BIOS drive) and SDB (2nd BIOS drive) are part of a MDADM raid(1) system. > > As soon as I plug in the third drive, the OS (or systemD) decides to put it into the SDB spot - I do NOT want that. > When I the use any of the grub2 utils I end up with "missing drive" errors. Try to switch physical connections of second and third drives, then you most likely will have the correct "BIOS" order of physical drives. As, as far as I understand, the letters are assigned in the order the bus scan discovers drives (or - though less likely - in reverse order, at least reverse order once was for network interfaces, like discovered ones were pushed into stack, and then used in the order they were popped out of the stack). Valeri > > If I leave the drive out NO problem. I have managed twice to have the machine booting with the third drive as SDC, when that happens I I do not get any error messages. > > > > Jobst > > -- ++++++++++++++++++++++++++++++++++++++++ Valeri Galtsev Sr System Administrator Department of Astronomy and Astrophysics Kavli Institute for Cosmological Physics University of Chicago Phone: 773-702-4247 ++++++++++++++++++++++++++++++++++++++++