NOTE: No changes are made to the partition table on the hard disk until the write "w" command is issued. Therefore, you can feel free to experiment, creating, deleting partitons, etc. any number of times before writing the changes to disk. Until you use the "w" command changes are merely kept track of in memory by the fdisk program.
While logged in as root use
fdisk to set up the RAID partitions. Starting with the SCSI drive:
root@bultaco:~# fdisk /dev/sdaLet's see the list of avaiable commands in fdisk:
Command (m for help): m Command action a toggle a bootable flag b edit bsd disklabel c toggle the dos compatibility flag d delete a partition l list known partition types m print this menu n add a new partition o create a new empty DOS partition table p print the partition table q quit without saving changes s create a new empty Sun disklabel t change a partition's system id u change display/entry units v verify the partition table w write table to disk and exit x extra functionality (experts only)Next let's print the partition table:
Command (m for help): p Disk /dev/sda: 9105 MB, 9105018880 bytes 64 heads, 32 sectors/track, 8683 cylinders Units = cylinders of 2048 * 512 = 1048576 bytes Device Boot Start End Blocks Id SystemThe drive has no defined partitions in the table, so we can create one now.
Command (m for help): n Command action e extended p primary partition (1-4) p Partition number (1-4): 1 First cylinder (1-8683, default 1): Using default value 1 Last cylinder or +size or +sizeM or +sizeK (1-8683, default 8683): Using default value 8683 Command (m for help): p Disk /dev/sda: 9105 MB, 9105018880 bytes 64 heads, 32 sectors/track, 8683 cylinders Units = cylinders of 2048 * 512 = 1048576 bytes Device Boot Start End Blocks Id System /dev/sda1 1 8683 8891376 83 LinuxThe final and essential step before writing this new partition table to disk is to change the partition type to "Linux raid auto" as indicated in the raidtab man page:
Every member disk/partition/device has a
superblock, which carries all information necessary
to start up the whole array. (for autodetection to
work all the 'member' RAID partitions should be
marked type 0xfd via fdisk) The superblock is not
visible in the final RAID array and cannot be
destroyed accidentally through usage of the md
device files, all RAID data content is available
for filesystem use.
Command (m for help): t Selected partition 1 Hex code (type L to list codes): L 0 Empty 1c Hidden W95 FAT3 70 DiskSecure Mult bb Boot Wizard hid 1 FAT12 1e Hidden W95 FAT1 75 PC/IX be Solaris boot 2 XENIX root 24 NEC DOS 80 Old Minix c1 DRDOS/sec (FAT- 3 XENIX usr 39 Plan 9 81 Minix / old Lin c4 DRDOS/sec (FAT- 4 FAT16 <32M 3c PartitionMagic 82 Linux swap c6 DRDOS/sec (FAT- 5 Extended 40 Venix 80286 83 Linux c7 Syrinx 6 FAT16 41 PPC PReP Boot 84 OS/2 hidden C: da Non-FS data 7 HPFS/NTFS 42 SFS 85 Linux extended db CP/M / CTOS / . 8 AIX 4d QNX4.x 86 NTFS volume set de Dell Utility 9 AIX bootable 4e QNX4.x 2nd part 87 NTFS volume set df BootIt a OS/2 Boot Manag 4f QNX4.x 3rd part 8e Linux LVM e1 DOS access b W95 FAT32 50 OnTrack DM 93 Amoeba e3 DOS R/O c W95 FAT32 (LBA) 51 OnTrack DM6 Aux 94 Amoeba BBT e4 SpeedStor e W95 FAT16 (LBA) 52 CP/M 9f BSD/OS eb BeOS fs f W95 Ext'd (LBA) 53 OnTrack DM6 Aux a0 IBM Thinkpad hi ee EFI GPT 10 OPUS 54 OnTrackDM6 a5 FreeBSD ef EFI (FAT-12/16/ 11 Hidden FAT12 55 EZ-Drive a6 OpenBSD f0 Linux/PA-RISC b 12 Compaq diagnost 56 Golden Bow a7 NeXTSTEP f1 SpeedStor 14 Hidden FAT16 <3 5c Priam Edisk a8 Darwin UFS f4 SpeedStor 16 Hidden FAT16 61 SpeedStor a9 NetBSD f2 DOS secondary 17 Hidden HPFS/NTF 63 GNU HURD or Sys ab Darwin boot fd Linux raid auto 18 AST SmartSleep 64 Novell Netware b7 BSDI fs fe LANstep 1b Hidden W95 FAT3 65 Novell Netware b8 BSDI swap ff BBT Hex code (type L to list codes): fd Changed system type of partition 1 to fd (Linux raid autodetect) Command (m for help): p Disk /dev/sda: 9105 MB, 9105018880 bytes 64 heads, 32 sectors/track, 8683 cylinders Units = cylinders of 2048 * 512 = 1048576 bytes Device Boot Start End Blocks Id System /dev/sda1 1 8683 8891376 fd Linux raid autodetect Command (m for help): w