Hello Stan, On Mon, Sep 27, 2021 at 08:33:54AM -0600, Stan Johnson wrote: > Having the above partitioning scheme seems to work ok with GRUB; the > reason I asked about the "Whole disk" partition is that some > partitioning tools (specifically fdisk, as I recall), refuse to create > additional partitions once "Whole disk" has claimed all of the sectors.
Oh ok, couldn't remember how that was - our Sparks are in Storage since a few years now. > In addition, there is an oddity (I think with parted, but I don't recall > now) where the "Whole disk" partition needed to exist, otherwise the > partitioner only recognized 1 GB. Perhaps this is related to parted > complaining during installation that the number of cylinders on the disk > exceeded the maximum of 65536 cylinders? Maybe parted is reading the > disk geometry from the third partition on the disk regardless of what's > there? No idea. > So I ended up using this partitioning scheme; note that parted complains > (but fdisk does not): > > # parted /dev/sda > GNU Parted 3.4 > Using /dev/sda > Welcome to GNU Parted! Type 'help' to view a list of commands. > (parted) print > Warning: The disk CHS geometry (562253,255,2) reported by the operating > system does not match the geometry stored on the disk label > (17849,255,63). > Ignore/Cancel? C > Model: SEAGATE ST3146807LC (scsi) > Disk /dev/sda: 147GB > Sector size (logical/physical): 512B/512B > Partition Table: unknown > Disk Flags: > (parted) quit Looks to me that parted did not recognize sun disklabel format. > # fdisk -l /dev/sda > Disk /dev/sda: 136.73 GiB, 146815737856 bytes, 286749488 sectors > Disk model: ST3146807LC > Geometry: 255 heads, 63 sectors/track, 17849 cylinders > Units: sectors of 1 * 512 = 512 bytes > Sector size (logical/physical): 512 bytes / 512 bytes > I/O size (minimum/optimal): 512 bytes / 512 bytes > Disklabel type: sun > > Device Start End Sectors Size Id Type Flags > /dev/sda1 0 1048575 1048576 512M 1 Boot > /dev/sda2 1060290 17837505 16777216 8G 83 Linux native > /dev/sda3 17848215 34625430 16777216 8G 83 Linux native > /dev/sda4 34636140 68190571 33554432 16G 83 Linux native > /dev/sda5 68195925 70293076 2097152 1G 82 Linux swap u > /dev/sda6 70300440 286744184 216443745 103.2G 83 Linux native The speciality of sun disklabel format is that sda1 contains the boot block (block 0) of the HD. I somehow misused that in the past to mirror the boot block in raid1 configurations of sda1. YMMV. > It appears that SILO and GRUB do something similar -- they appear to be > installed in the 1024-byte "boot block" of an ext2 filesystem; for more > information, see this link for ext2 filesystem structure: > > http://www.science.smith.edu/~nhowe/teaching/csc262/oldlabs/ext2.html Yep, the filesystem needs to leave space for that boot block on (old) sparc machines on sda1 starting at sector 0. I wonder if there is an historic explanation for that somehow wicked setup on spark machines: Originally booting from a tape? Greetings Hermann
