Ubiquity changes an existing partition size

[Art1]

I would like to install Linux Mint 14 Cinnamon on a hard disk with prepared partitions. The partition for Mint has the size 20480,95 MB (40001850 sectors, 2490 cylinders). When I install from the live CD with Ubiquity, I choose "Installation type: Something else", then in the partition editor I select the existing partition for Mint and I click on "Change", because I want to use it as a root mount point "/". But the editor isn't capable to leave the partition size unchanged, and I must choose the new size in MB, so 20480 MB or 20481 MB. I hadn't this problem with the MATE edition or with the older releases. Is this a new bug in Ubiquity? Is it possible to choose the mount point without changing the partition size?

[usbtux]

http://youtu.be/kBrRL6iG0NM using the installer (ubiquity) after setting up your partitions. Or installing over an existing install partitions.

Yes, you should be able to use the existing partition sizes - however the problem may be associated with block size issues. If you want to keep the sizes due to the existence of backups. make the root and home partitions slightly larger and swap smaller.

[Art1]

Thank you, but I don't understand why it isn't possible to just select a mount point without touching the partition parameters.

[viking777]

This is not only possible, it is the default setting. If you are being asked to change partition size then the only explanation I can think of is that the installer is not happy with the partition alignment and needs to change it slightly to ensure correct installation. In all the years I have been using Ubiquity (and I last used it 3 days ago) I have never been asked to resize a partition just to select it as /.

[Art1]

So, I have found the reason. Before installing, I updated the packages (I made my custom install CD), so during the installation I used Ubiquity 2.12. On the original Mint 14 DVD, there is Ubiquity 2.10 which works without problems with partitions. If I apt-get update the Ubiquity to 2.12, it looks a litte different and it does what I wrote above. Probably Ubiquity will change like this in the next Ubuntu and Mint release and I hope that somebody will repair this bug.

[catweazel]

I hope that somebody will repair this bug.

It's likely by design, and not a bug. Partitions need to reside on certain boundaries to ensure that the file system isn't clagged by the effects of odd size drive head movements. The installer is probably making sure that the partition boundaries are optimal for your hard disk.

[Art1]

OK, I understand and it is possible, but I use these partitions since several years with some disk utilities from different operating systems without any warning and I don't like if I have no choice to leave it unchanged. If Ubiquity don't like the size, it could warn me, but there was no message. In my opinion, this change isn't very user friendly.

[catweazel]

I don't like if I have no choice

You do have a choice. Create the partitions yourself. Don't align them to 1MB boundaries if the installer gives you the creeps.