On 11/22/18 8:24 PM, Daniel Fishman wrote: > Hello, > > I am trying to install Debian on a 4TB external HDD. Since I want > to boot the HDD (also) on old systems which support only BIOS, > and since the HDD is larger than 2TB, I decided to go with GPT > partition table and BIOS boot (or, in other words: BIOS/GTP). > I partitioned the HDD accordingly (see the details below), and > installed Debian. During a pre-installation configuration the > installer recognized BIOS boot partition, I configured the root > partition as ext4 and installed grub into the disk's MBR. But > when (after an installation) I am trying to boot the HDD, I receive > an error message: 'error: unknown filesystem' and drop into a > grub rescue mode. > > What is the problem here and how it can be solved? It seems as > though grub's Stage 1.5 loader (that is - core.img, which is > supposed to be embedded in BIOS boot partition) doesn't contain > modules needed to read ext4 filesystem, which seems very strange. > > > Following are a bit more details about the partitions: > > I used the following command to partition the HDD: > > parted -s /dev/sdb mklabel gpt mkpart BIOS_boot ext2 1MiB 2MiB \ > mkpart swap linux-swap 2MiB 16000MiB mkpart data ext2 16000MiB 100% \ > set 1 bios_grub > > [root@arch]# parted /dev/sdb unit MiB print > Model: WD Elements 25A1 (scsi) > Disk /dev/sdb: 3815415MiB > Sector size (logical/physical): 512B/4096B > Partition Table: gpt > Disk Flags: > > Number Start End Size File system Name Flags > 1 1.00MiB 2.00MiB 1.00MiB bios_grub > 2 2.00MiB 16000MiB 15998MiB linux-swap(v1) > 3 16000MiB 3815414MiB 3799414MiB > > > Debian's installation was done on x64 BIOS-only system. >
Hi Daniel, in case of BIOS and GPT you have to create a partition for second stage of GRUB. If I can remember correctly its size should be less than 50MB. HTH Kind regards Georgi
