I have a new computer that I have imaged using PXE. It loads a kernel, initrd and verifies if it needs to apply an image. If it does, it goes through some logic of partitioning (BIOS, non-GPT) the disk and applying a disk image (SLES 12 SP2) which it TFTPs over the network. From this environment, it then loads the kernel and initrd directly from the boot partition and kicks off systemd from the root partition. However, if I try to boot the drive directly without PXE booting, I get the generic “No bootable OS found” error and no GRUB.
So from the OS, I got through the usual routine..
The drive is an SSD. Verify my current disk and partitioning:
# fdisk -l Disk /dev/sda: 119.2 GiB, 128035676160 bytes, 250069680 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes Disklabel type: dos Disk identifier: 0x63305a1b Device Boot Start End Sectors Size Id Type /dev/sda1 2048 2056319 2054272 1003.1M 82 Linux swap / Solaris /dev/sda2 2058240 250067789 248009550 118.3G 83 Linux # lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sda 8:0 0 119.2G 0 disk ├─sda1 8:1 0 1003.1M 0 part [SWAP] └─sda2 8:2 0 118.3G 0 part / # cat /proc/scsi/scsi Attached devices: Host: scsi0 Channel: 00 Id: 00 Lun: 00 Vendor: ATA Model: SanDisk SD7SN3Q- Rev: 0006 Type: Direct-Access ANSI SCSI revision: 05
Install GRUB2 to the MBR:
# grub2-install /dev/sda Installing for i386-pc platform. Installation finished. No error reported.
Then generate my configuration:
# grub2-mkconfig -o /boot/grub2/grub.cfg Generating grub configuration file ... Found linux image: /boot/vmlinuz-4.4.120-92.70-default Found initrd image: /boot/initrd-4.4.120-92.70-default done
Now in the UEFI options, I have UEFI boot disabled. Instead, it tries to legacy PXE and legacy boot the drive. So I’d expect when it attempts to boot said disk, it will look at the first 512MB to find the MBR and boot GRUB. This part does not seem to happen however.. Is there anything else I could possibly check to see where this may be going wrong?
Had to mark the partition bootable using fdisk.
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