Home / ubuntu / Questions / 1127029
In Process
markling
Asked: 2019-03-20 12:29:07 +0800 CST

Why does this fdisk delete/new operation start at a different sector?

  • 772

And will it lose my data?

I reduced the size of my filesystem. Now reducing the size of the partition in fdisk, I notice that fdisk wants to create the resized partition at a different sector.

Here's the partitions as they stood before I attempted to resize:

                start   end         sectors    size id type
/dev/sda1  *      2048    1499135    1497088   731M 83 Linux
/dev/sda2       1501182 976771071    975269890 465G  5 Extended
/dev/sda5       1501184 976771071    975269888 465G 83 Linux

I deleted partition 5, and went to create a new one in the same place at the reduced size.

But fdisk says:

Adding logical partition 5
First sector (1503230-976771071, default 1503232)

It wants to start the new partition in a different sector. Why would it want to do this and will it lose my data?

btw: fdisk reported, upon displaying the partitions originally: Partition 2 does not start on a physical sector boundary.

These were the partitions the Ubuntu installer created, using the standard settings for an encrypted lvm install, and opting to wipe the disk.

system-installation resize partitioning fdisk

1 Answers

  1. Actually, in a round about way, it didn't wipe the data. That still leaves the question why it chose different sectors. The question is now academic.

    Inevitably, the extended partition that contained partition 5 (partition 2) had to be resized as well. It's not necessary to resize partition 5 first. Because to resize partition 2 you have to delete it, and then create a new extended partition of the desired size. That of course deletes partition 5. So you then create a new partition 5 of the desired size. And it gives some odd reports about what sectors it's using, but the end result is the sector starts remain the same as they were.

    • 0