Terje J. Hanssen composed on 2015-09-06 16:54 (UTC+0200):
I have experienced that installation of a second openSUSE version (for dual-boot) looze the menu.lst and fails to boot after the installation. I have also found a work-around to fix this, but I'm afraid unexperienced openSUSE users can give up and drop openSUSE for further testing if and when this happends. Therefore I wonder if the installation can be made more robust to avoid this confusing issue.
In my experience, all Linux installers could and should do better WRT assumptions applied when the installation target lives in a multiboot environment. Likely UEFI will eventually obsolete some of those assumptions, but others will survive, while BIOS systems will be around for a while yet.
Scenario: 1) On my hp laptop the SSD disk (sda 150G) was sliced in six partitions and applied as follows for a first installed andworking openSUSE 13.2:
/dev/sda1 2G swap
Above is one of the more perverse default BIOS installation behaviors. Primary partitions have special significance in BIOS installations. Those shouldn't be wasted on a swap partition. Swap belongs on sdX5 whenever possible, close to front of disk for high speed, but not wasting a primary partition table entry.
/dev/sda2 20G / (root for openSUSE 13.2) /dev/sda3 40G /home /dev/sda4 87G (Extended) /dev/sda5 20G (available for second root)
https://old-en.opensuse.org/Bugs/grub#How_does_a_PC_boot_.2F_How_can_I_set_u... alludes to the problem with the above partitioning. The default configuration sustains well on a BIOS system only when there is no more than one Linux installation, and when there is no non-Linux installation, on the boot/primary storage media, so that it doesn't matter where the bootloader gets installed. Once a second system is introduced, defaults cause conflict over what does and should control the boot process. When instead at least two primaries are utilized for partitions that can readily host a Linux bootloader, and a third if necessary for a Windows bootloader, damage to be caused by a second or successive operating system installation can be held to virtual zero. Each primary can host a bootloader, and boot control can be selected/managed by the virtually painless process of moving the boot flag to the desired partition, leaving the MBR code block populated by generic startup code rather than any more complicated and dependant code such as that placed there and in the space immediately following by Grub2.
/dev/sda6 67G /data (additional user data)
2) Next I installed Leap 42.1 M2 from the DVD, selected Expert partitioning, imported existing mount points and selected
/dev/sda5 formatted ext4 as root for Leap /dev/sda3 unformatted and mounted as shared /home for 13.2 and Leap (yes I know the shared /home has some drawbacks but more benefits in my opinion)
Beyond adding some extra appliactions and setup SSH, the installation else was kept as default. I didn't change anything regarding the bootloader installation.
The installation went ok until the first reboot, the it stopped on the black console sreen after the word 'GRUB' and nothing else. I tried to startup again and the same happened; no GRUB menu.lst didn't become available. That is, neither the previous working openSUSE 13.2 nor 42.1 could be started.
Sad but typical result of usurpation caused by Gru* instead of legacy code in the MBR, and not thinking ahead from the point of initial OS installation. It's avoidable by thoughtful partitioning in advance of installing anything. ...
Can this issue be avoided to make dual or multiboot installations easier?
1-Boot agnostically from a primary instead of from MBR. 2-Reserve primaries for use by partitions that might ever be booted from. 3-If eventually the system will be true multiboot, more than one Linux, or more than two anything, consider using one primary for a partition to be used mounted to /boot at most only until a second OS will be installed, and afterwards reserve it for what can be crudely described as chainloader-only service, to be managed by the sysadmin instead of directly by any OS. -- "The wise are known for their understanding, and pleasant words are persuasive." Proverbs 16:21 (New Living Translation) Team OS/2 ** Reg. Linux User #211409 ** a11y rocks! Felix Miata *** http://fm.no-ip.com/ -- To unsubscribe, e-mail: opensuse-factory+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-factory+owner@opensuse.org