Partitioning for &arch-title;
ia64 EFI firmware supports two partition table (or disk label)
formats, GPT and MS-DOS. MS-DOS is the format typically used on i386
PCs, and is no longer recommended for ia64 systems. The installer
provides two partitioning programs,
cfdisk and
parted.
parted can manage both GPT and MS-DOS tables, while
cfdisk can only manage MS-DOS tables. It is very
important to note that if your disk has previously been partitioned
with a GPT table, and you now want to use MS-DOS tables, you must use
parted to create the new partition table. This is
because the two tables use different areas of a disk, and
cfdisk does not know how to remove a GPT table.
An important difference between cfdisk and
parted is the way they identify a partition
``type''. cfdisk uses a byte in the partition
table (for example, 83 for a linux ext2 partition), while
parted identifies a partition ``type'' by examining
the data on that partition. This means that parted
will not consider a partition to be a swap partition until you format
it as such. Similarly, it won't consider a partition a linux ext2
partition until you create a file system on it.
parted does allow you to create file systems and
format swap space, and you should do that from within
parted.
Unfortunately, parted is a command line driven
program and so not as easy to use as cfdisk.
Assuming that you want to erase your whole disk and create a GPT table
and some partitions, then something similar to the following command
sequence could be used:
mklabel gpt
mkpartfs primary fat 0 50
mkpartfs primary linux-swap 51 1000
mkpartfs primary ext2 1001 3000
set 1 boot on
print
quit
That creates a new partition table, and three partitions to be used as
an EFI boot partition, swap space, and a root file system. Finally it
sets the boot flag on the EFI partition. Partitions are specified in
Megabytes, with start and end offsets from the beginning of the disk.
So, for example, above we created a 1999MB ext2 file system starting
at offset 1001MB from the start of the disk. Note that formatting swap
space with parted can take a few minutes to
complete, as it scans the partition for bad blocks.
Boot Loader Partition Requirements
ELILO, the ia64 boot loader, requires a partition containing a FAT
file system. If you used GPT partition tables, then that partition
should have the boot flag set; if you used
MS-DOS partition tables, then that partition should be of type "EF".
The partition must be big enough to hold the boot loader and any
kernels or RAMdisks you may wish to boot. A minimum size would be
about 16MB, but if you are likely to be doing development, or
experimenting with different kernels, then 128MB might be a better
size.