[OmniOS-discuss] Warning that partition is too large when mirroring identical disks in root pool

[Willard Korfhage]

I just installed OmniOS r151008j last night, and today I wanted to 
mirror rpool, but have a warning about the disk size. I have 2 Seagate 
1TB disks (model ST1000LM024HN), and my OmniOS install is on one of 
them. I told the install to use the whole disk. Some version of 
OpenIndiana was previously installed on the disk. The install went 
without any problem.

c2t0d0 is the disk with OmniOS
c2t1d0 is supposed to be its mirror

To do the mirroring, following the directions in the wiki, I did

root at s1:~# pfexec fdisk -B c2t1d0p0
root at s1:~# pfexec prtvtoc /dev/rdsk/c2t0d0s2 | pfexec fmthard -s - 
/dev/rdsk/c2t1d0s2
fmthard: Partition 2 specifies the full disk and is not equal
full size of disk. The full disk capacity is 1953407610 sectors.
fmthard: Partition 2 specified as 1953471870 sectors starting at 0
  does not fit. The full disk contains 1953407610 sectors.
fmthard: New volume table of contents now in place.

At this point I stopped, and haven't done the mirror.

For the disk with the install, format reports

Current Disk = c2t0d0
<ATA-ST1000LM024HN-M-0001 cyl 60797 alt 2 hd 255 sec 126>
/pci at 0,0/pci8086,1c02 at 1f,2/disk at 0,0

and further information is

root at s1:~# pfexec prtvtoc /dev/rdsk/c2t0d0s2
* /dev/rdsk/c2t0d0s2 partition map
*
* Dimensions:
*     512 bytes/sector
*     126 sectors/track
*     255 tracks/cylinder
*   32130 sectors/cylinder
*   60799 cylinders
*   60797 accessible cylinders
*
* Flags:
*   1: unmountable
*  10: read-only
*
* Unallocated space:
*       First     Sector    Last
*       Sector     Count    Sector
*           0     32130     32129
*
*                          First     Sector    Last
* Partition  Tag  Flags    Sector     Count    Sector  Mount Directory
        0      2    00      32130 1953375480 1953407609
        2      5    01          0 1953471870 1953471869
        8      1    01          0     32130     32129

Any idea what is going on?

I tried to format the disk without the install (c2t1d0), just to start 
with a completely fresh disk, but it doesn't work. This appears to be a 
long-standing (11-month old) Illumos bug 
(https://www.illumos.org/issues/3610)