Hi Hermann, On 9/27/21 1:56 AM, [email protected] wrote: > Hi Stan, > > On Sat, Sep 25, 2021 at 11:34:59PM -0600, Stan Johnson wrote: >> Not knowing what the preferred size should be for a GRUB /boot >> partition, I decided to let Guided Partioning use its defaults for >> /dev/sda. As I recall, the partitioner warned that the number of >> cylinders on the disk exceeded the maximum of 65536, but the creation of >> filesystems and the rest of the installation proceeded anyway, without >> any other noticeable errors. >> >> The layout for /dev/sda is as follows: >> >> # fdisk -l /dev/sda >> Disk /dev/sda: 136.73 GiB, 146815737856 bytes, 286749488 sectors >> Disk model: ST3146807LC >> Geometry: 255 heads, 2 sectors/track, 37965 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 1000109 1000110 488.3M 1 Boot >> /dev/sda2 1000110 284748299 283748190 135.3G 83 Linux native >> /dev/sda3 0 286749029 286749030 136.7G 5 Whole disk >> /dev/sda4 284748300 286749029 2000730 976.9M 82 Linux swap > this is a sun disk partitioning scheme - not shure, if this is well supported > with grub.
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. 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? 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 # 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 > >> -> Question 1: If I don't plan to install Solaris, is it safe to remove >> the "Whole disk" partition (/dev/sda3)? > AFAIR sun disklabels allows up to 8 entries - so there is no advantage in > removing the solaris standard whole disk entry. > >> -> Question 2: What is the best size for /boot (/dev/sda1)? After >> installation, the /boot partition had only about 57 MB of files. > What's on this partition? Only Grub files or also the kernel stuff? > AFAIR I used around 100-200MB years ago, but this was with SILO. My experience is mostly with m68k and powerpc Macs, so please excuse my lack of Sun Sparc knowledge. I recall from many years ago that there is a "bootblk" on Sparc systems. I learned this after finally reading the manual when a full restore of Solaris on a new disk failed to boot because the bootblk was missing. 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 At appears that at least SILO wants the "Boot" partition to be ext2. These are the only files that I have in my "Boot" partition: # ls -l total 172 lrwxrwxrwx 1 root root 1 Oct 22 2020 boot -> . lrwxrwxrwx 1 root root 1 Oct 22 2020 etc -> . -rw-r--r-- 1 root root 1024 Aug 19 2012 fd.b -rw-r--r-- 1 root root 512 Aug 19 2012 first.b -rw-r--r-- 1 root root 1024 Aug 19 2012 generic.b -rw-r--r-- 1 root root 692 Aug 19 2012 ieee32.b -rw-r--r-- 1 root root 7040 Aug 19 2012 isofs.b drwx------ 2 root root 16384 Sep 26 16:26 lost+found -rw-r--r-- 1 root root 7680 Oct 22 2020 old.b -rw-r--r-- 1 root root 53248 Oct 24 2020 second.b -rw-r--r-- 1 root root 525 Sep 26 16:36 silo.conf -rw-r--r-- 1 root root 473 Oct 24 2020 silo.conf.save -rw-r--r-- 1 root root 50994 Aug 19 2012 silotftp.b -rw-r--r-- 1 root root 512 Aug 19 2012 ultra.b The Boot partition does NOT have to be mounted as /boot, though it can be. Here's my silo.conf file: # cat /mnt/boot/silo.conf default=Debian_sid read-only timeout=100 image=/boot/vmlinuz-3.2.0-4-sparc64 partition=2 root=/dev/sda2 label=Debian_7 initrd=/boot/initrd.img-3.2.0-4-sparc64 image=/boot/vmlinuz partition=3 root=/dev/sda3 label=Debian_sid initrd=/boot/initrd.img image=/boot/vmlinuz partition=4 root=/dev/sda4 label=Gentoo initrd=/boot/initrd.img image=/boot/vmlinuz partition=1 root=/dev/sdb1 label=Backup initrd=/boot/initrd.img The advantage to not mounting the Boot partition as /boot is that any given OS will boot using SILO as long as I create the appropriate symbolic links for /boot/vmlinuz and /boot/initrd (or I can hardcode the names as I did above for Debian 7). And according to the silo man page, silo.conf can be changed at any time using a regular text editor, and SILO doesn't need to be re-installed after changes. If typos cause the system to fail to boot, just use rescue mode on any installation CD to fix silo.conf. I keep Debian 7 so I can re-install the SILO boot block if necessary (for example on a new disk). -Stan
