rasta wrote:I think that you are generally correct. The method of expanding the / partition is apparently quite complicated, and is still under investigation:
One thing I see is not being made clear to your colleagues in that forum: when you enlarge a drive using CloneVDI you are enlarging the drive
, not any filesystems or partitions on the drive. It's the same effect you would get in the physical world if you had some low level tool which copied all of the sectors off a 20GB drive and over to a 40GB one, and then put the 40GB drive into your PC. Everything would still work (driver issues aside), but the filesystem is still only using the first 20GB of the drive, and that's precisely the situation you have here.
Dynamically growing drives in VBox don't grow the filesystem either. As far as the Solaris filesystem is concerned, the drive (rather, the root partition) has always been ~20GB. However, unknown to Solaris, some of the sectors in that space are only allocated on demand (i.e. when first written to). So, until every sector has been written to the host VDI file will be less than 20GB.
Your colleagues mention that you can't add extents to the root volume of a UFS system - that's something I hadn't appreciated.
Bear in mind also that you have a backup, so you can try the "dangerous" VTOC zapping ideas with in fact no danger at all. If it doesn't work you just restore your backup, or create another clone of the original.
If I understand the suggestion correctly, you are supposed to use fdisk to delete the existing partition (this should just mark the partition table entry as empty, without actually changing any data in there). You then create a new partition that fills the drive. The first 20GB of that partition should contain the old data. Then somehow you need to zap the old VTOC label - I don't quite grasp how that is done, but maybe you do.
Don't worry about the cylinder size changing. A cylinder is always 63 sectors in a VBox virtual disk.
Incidentally, I'm still not sure you've pinned down what filesystem you are using with certainty. Both UFS and ZFS have been mentioned. This is a rather fundamental question!