Joined: 04 Oct 2003
|Posted: Wed Feb 02, 2005 1:54 pm Post subject: fdisk and default start cylinder - differs from x86
|I've noticed a difference between fdisk's behaviour when
providing a default start cylinder on different platforms.
Sometimes, when making a new partition, the default start
cylinder is the same number as the end cylinder on the
E.g., you end up with something like this, using the defaults:
/dev/sda1 0 27 63612 83 Linux native
/dev/sda2 u 27 240 499472 82 Linux swap
These OS have been observed to increment the default start
cylinder by one over the previous partition's end cylinder:
Slackware 9, running fdisk 2.12
Gentoo x86, running fdisk 2.12i
These OS have been observed to use the same value as
the previous partition end cylinder, for the default start cylinder
on a new partition:
Gentoo sparc, running fdisk 2.12
Xandros x86 (Debian based), running fdisk 2.12
In the case of the Debian based x86, I had an extended partition.
We tested to see if there was a difference with logical partitions,
since the examples I had of shared start and end cylinders
were inside extended partition.
First, I deleted all partitions, and started making new ones.
I made primary partitions and then logical ones.
Doing it this way, I could not recreate the problem of overlapping
cylinder numbers in the default suggested values.
I quit fdisk (no write), restarted it, and deleted only a couple
of logical partitions from the end of my existing 8 partition set up.
Now, creating new partitions did cause the default start cylinder
to be the same as the previous end cylinder.
This is a topic that spans outside of sparc, but since I'm seeing
the problematic (at least potentially) behaviour on the sparc,
I thought perhaps someone here would know about this issue.