Thank you Richard, your answer helped a lot.
On Fri, Nov 20, 2009 at 1:12 AM, Richard L. Hamilton <rlhamil at smart.net>
wrote:
> On x86, there are two levels of partitions: fdisk partitions, and within the
> Solaris partition, "slices". ?Something ending in p0 is the whole disk; p1
> through p4 are
so using format, i can get the c7d1:
Cylinders
Partition Status Type Start End Length %
========= ====== ============ ===== === ====== ===
1 Active Solaris2 1 5874 5874 10
and then prtvtoc:
prtvtoc /dev/rdsk/c7d1p0
* /dev/rdsk/c7d1p0 partition map
* First Sector Last
* Partition Tag Flags Sector Count Sector
Mount Directory
0 2 00 32130 188603100 188635229
2 5 01 0 188635230 188635229
8 1 01 0 32130 32129
>From above, I know the slice number is 0, 2, and 8 (not fdisk partition
>number):
fstyp /dev/rdsk/c7d1s0
zfs
fstyp /dev/rdsk/c7d1s2
zfs
fstyp /dev/rdsk/c7d1s8
zfs
but problem is that solaris slice is not visible at the allocation
table level, right? (both Windows + Linux's fdisk recognize these
partition). Therefore, if I were to use any other OS I can only see
the partition 1 - with cylinder from 1 to 5874, correct? (I think
Linux will shift it to start from zero, so 0-5873?)
Thank you for the detailed explanation, now I can safely use my other
parts of the disk :-).
> each an entire fdisk partition; something ending in s0 through s15 is a
> Solaris slice
> (within the Solaris fdisk partition). ?By convention, s2 encompasses the
> entire fdisk
> partition that contains it. ?Usually, s0 is root, and s1 is swap. ?The others
> need not be
> used unless one wants more filesystems (splitting out /var or /export/home,
> for example).
>
> Any given OS can only own one primary (fdisk) partition on a disk.
>
> Solaris cannot be installed into a logical partition (subdivision of an
> extended fdisk partition).
> It's ability to address logical partitions is AFAIK limited to pcfs, where
> you might see a
> filesystem mounted from something like ? ?/dev/dsk/c0t0d0p2:d
> (a colon letter or colon number suffix indicating a logical partition within
> p2).
>
> I don't promise that I got that last paragraph right...
>
> Hope that helps.
>
> Now, I'm going to start rambling, and get really confusing (and confused).
>
> On SPARC, disks don't normally have fdisk partitions, they have a Sun VTOC
> with Solaris
> slices 0 through 7. ?However, for a non-boot disk, fdisk partitions can be
> recognized, so
> that for example pcfs (FAT) filesystems on a USB drive can be read.
>
> Complicating all the above is EFI, an alternative to fdisk partitions. ?Both
> x86 and SPARC
> can handle it at the OS level. ?It doesn't need extended+logical partitions,
> because it allows
> more than four. ?I would suppose (but haven't checked) that on x86 the OS
> could boot from
> an EFI partition if the BIOS supported it. ?I'm not aware of any OpenBoot
> firmware for SPARC
> that can boot from an EFI partition. ? If zfs is given an entire disk, I
> think it will set it up
> as a single EFI partition (and default to enabling drive write cache, issuing
> cache flush
> commands as needed to ensure consistency). ?Not sure what happens when one
> has a boot
> disk (that at least on SPARC AFAIK can't be EFI) where zfs has the whole
> disk...whether or
> not it would enable the disk's write cache.
>
> It is all (IMO) a bit confusing...would be nice to see the device naming
> conventions
> fully spelled out with examples, for both x86 and Solaris. ?And I think there
> have been
> a lot of requests to be able to install into a logical partition for
> multiboot configurations
> (esp since I think Linux can do that). ?One problem with that might be that
> it would
> mean rearranging the minor devices to reflect the presence of an additional
> type of
> partitioning, which would mess with existing installations. ?A good solution
> might not
> be easy, and newer systems should support EFI which doesn't need logical
> partitions,
> so (I'm guessing) despite the demand, there's not much incentive to go to all
> that trouble.
>
> So it's flexible, but for some people trying to run more than four OSs on a
> system that
> can only recognize fdisk labels, it's not ideal...
> --
> This message posted from opensolaris.org
> _______________________________________________
> opensolaris-help mailing list
> opensolaris-help at opensolaris.org
>
--
Regards,
Peter Teoh
