[Solved] Warning: Partition # does not end on cylinder boundary

[oio11]

Why “partition X does not end on cylinder boundary” warnings don’t matter

While reviewing the partion layout on one of my hard drives, I noticed a number of “Partition X does not end on cylinder boundary” messages in the fdisk output:

$ fdisk /dev/sda

The number of cylinders for this disk is set to 9726.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
   (e.g., DOS FDISK, OS/2 FDISK)

Command (m for help): p

Disk /dev/sda: 80.0 GB, 80000000000 bytes
255 heads, 63 sectors/track, 9726 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0xac42ac42

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1          26      204800   83  Linux
Partition 1 does not end on cylinder boundary.
/dev/sda2              26         287     2097152   83  Linux
Partition 2 does not end on cylinder boundary.
/dev/sda3             287        9726    75822111+  8e  Linux LVM

This was a bit disconcerting at first, but after a few minutes of thinking it dawned on me that modern systems use LBA (Logical Block Addressing) instead of CHS (Cylinder/Head/Sector) to address disk drives. If we view the partition table using sectors instead of cylinders:

$ sfdisk -uS -l /dev/sda

Disk /dev/sda: 9726 cylinders, 255 heads, 63 sectors/track
Units = sectors of 512 bytes, counting from 0

   Device Boot    Start       End   #sectors  Id  System
/dev/sda1   *        63    409662     409600  83  Linux
/dev/sda2        409663   4603966    4194304  83  Linux
/dev/sda3       4603967 156248189  151644223  8e  Linux LVM
/dev/sda4             0         -          0   0  Empty

We can see that we end at a specific sector number, and start the next partition at that number plus one. I must say that I have grown quite fond of sfdisk and parted, and they sure make digging through DOS and GPT labels super easy.

http://prefetch.net/blog/index.php/2009/09/12/why-partition-x-does-now-end-on-cylinder-boundary-warnings-dont-matter/