Help needed: Partitioned software raid > 2TB

[Christian Schmidt <lkml@digadd.de>]

Hi everyone,

I added a drive to a linux software RAID-5 last night. Now that worked
fine... until I changed the partition table.

Disk /dev/md_d5: 2499.9 GB, 2499990978560 bytes
2 heads, 4 sectors/track, 610349360 cylinders
Units = cylinders of 8 * 512 = 4096 bytes

      Device Boot      Start         End      Blocks   Id  System
/dev/md_d5p1               1      244142      976566   83  Linux
/dev/md_d5p2          244143     5126956    19531256   8e  Linux LVM
/dev/md_d5p3         5126957   488279488  1932610128   8e  Linux LVM

This is how the layout looked before the changes.

      Device Boot      Start         End      Blocks   Id  System
/dev/md_d5p1               1      244142      976566   83  Linux
/dev/md_d5p2          244143     5126956    19531256   8e  Linux LVM
/dev/md_d5p3         5126957    73478448   273405968   8e  Linux LVM

This is how it looks now - the fdisk tools (fdisk/cfdisk) are unable to
crate a single partition > 2TB. Of course now LVM complains that the PV
is too small:

  WARNING: Physical Volume /dev/md_d5p3 is too large for underlying device
  PV Size               260.74 GB / not usable 8192.00 EB

I was able to restore a somewhat close partition table now... Close
enough for the LVM to work correctly.

      Device Boot      Start         End      Blocks   Id  System
/dev/md_d5p1               1      244142      976566   83  Linux
/dev/md_d5p2          244143     5126956    19531256   8e  Linux LVM
/dev/md_d5p3         5126957   488279495  1932610156   8e  Linux LVM
/dev/md_d5p4       488279496    73478448   488279460   8e  Linux LVM

Where is the inherent limit? The partitioning software, or partitioning
all by itself?

Regards,
Christian