Re: Grub2 (Wheezy) booting off either disk in a RAID1 mirror
Andrew Wood a écrit : One further question though when doing this it gives the option of installing grub on both sda and sdb (which I selected) but also md1 which is the main root file system (which I left unselected ). Under what circumstances would you choose this? Presumably only if grub was being used as a chainloader with something else in the MBR? I guess so. The something else would have to understand Linux md software RAID, so it probably would be another GRUB. There is a cleaner way to boot GRUB from another GRUB than chainloader : multiboot the core.img file in /boot/grub. However a software RAID device does not match any BIOS device, so I doubt that grub-install would accept it. -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: https://lists.debian.org/555e5cd5.6080...@plouf.fr.eu.org
Re: Grub2 (Wheezy) booting off either disk in a RAID1 mirror
On 19/05/15 18:38, Andrew Wood wrote: On 18/05/15 23:18, Pascal Hambourg wrote: It works, but the right way is to reconfigure the grub-pc package with # dpkg-reconfigure grub-pc and choose to install the bootloader on both disks. This way the bootloader will be automatically reinstalled properly when the package is upgraded. If the system boots from UEFI with grub-efi-*, it gets a little different though. Excellent thats worked perfectly thanks. One further question though when doing this it gives the option of installing grub on both sda and sdb (which I selected) but also md1 which is the main root file system (which I left unselected ). Under what circumstances would you choose this? Presumably only if grub was being used as a chainloader with something else in the MBR? -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: https://lists.debian.org/555b9305.5090...@perpetualmotion.co.uk
Re: Grub2 (Wheezy) booting off either disk in a RAID1 mirror
On 18/05/15 23:18, Pascal Hambourg wrote: It works, but the right way is to reconfigure the grub-pc package with # dpkg-reconfigure grub-pc and choose to install the bootloader on both disks. This way the bootloader will be automatically reinstalled properly when the package is upgraded. If the system boots from UEFI with grub-efi-*, it gets a little different though. Excellent thats worked perfectly thanks. -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: https://lists.debian.org/555b7532.9070...@perpetualmotion.co.uk
Re: Grub2 (Wheezy) booting off either disk in a RAID1 mirror
On Mon, May 18, 2015 at 02:52:21PM +0100, Andrew Wood wrote: Ive got 2 disks in a RAID1 mirror and am trying to setup Grub 2 so that I can boot from either disk if one fails. Ive tried using dd to copy the MBR over but when booting from one of the disks I just get the word GRUB which I guess is because its looking for the stage 2 loader on the other disk? How can I configure Grub2 correctly such that I can boot with either disk removed? I think you should be able to install grub (that is, run grub-install) for both devices (grub-install /dev/sda ; grub-install /dev/sdb # for example). Thanks -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: https://lists.debian.org/5559ee95.3040...@perpetualmotion.co.uk -- For more information, please reread. signature.asc Description: Digital signature
Grub2 (Wheezy) booting off either disk in a RAID1 mirror
Ive got 2 disks in a RAID1 mirror and am trying to setup Grub 2 so that I can boot from either disk if one fails. Ive tried using dd to copy the MBR over but when booting from one of the disks I just get the word GRUB which I guess is because its looking for the stage 2 loader on the other disk? How can I configure Grub2 correctly such that I can boot with either disk removed? Thanks -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: https://lists.debian.org/5559ee95.3040...@perpetualmotion.co.uk
Re: Grub2 (Wheezy) booting off either disk in a RAID1 mirror
Darac Marjal a écrit : On Mon, May 18, 2015 at 02:52:21PM +0100, Andrew Wood wrote: Ive got 2 disks in a RAID1 mirror and am trying to setup Grub 2 so that I can boot from either disk if one fails. Ive tried using dd to copy the MBR over but when booting from one of the disks I just get the word GRUB which I guess is because its looking for the stage 2 loader on the other disk? How can I configure Grub2 correctly such that I can boot with either disk removed? I think you should be able to install grub (that is, run grub-install) for both devices (grub-install /dev/sda ; grub-install /dev/sdb # for example). It works, but the right way is to reconfigure the grub-pc package with # dpkg-reconfigure grub-pc and choose to install the bootloader on both disks. This way the bootloader will be automatically reinstalled properly when the package is upgraded. If the system boots from UEFI with grub-efi-*, it gets a little different though. -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: https://lists.debian.org/555a6543.6010...@plouf.fr.eu.org
Re: Grub2 (Wheezy) booting off either disk in a RAID1 mirror
Darac Marjal wrote: Andrew Wood wrote: Ive got 2 disks in a RAID1 mirror and am trying to setup Grub 2 so that I can boot from either disk if one fails. Ive tried using dd to copy the MBR over but when booting from one of the disks I just get the word GRUB which I guess is because its looking for the stage 2 loader on the other disk? How can I configure Grub2 correctly such that I can boot with either disk removed? I think you should be able to install grub (that is, run grub-install) for both devices (grub-install /dev/sda ; grub-install /dev/sdb # for example). Using grub-install /dev/sda ; grub-install /dev/sdb should definitely work for both disks. It is definitely good to test. Andrew I applaud you for doing the testing of the installation. That is awesome. If all else fails and it were me I would swap the cables so that the order of sda and sdb are reversed. Then use grub-install /dev/sda to write the mbr onto the new sda drive. Then swap them back, although that shouldn't matter at that point. It is good to know that you can use the debian-installer in rescue mode to boot and chroot to the system in order to run grub-install there even if the BIOS booting drives won't boot. Bob signature.asc Description: Digital signature
