Comment 5 for bug 1564977

The sda vs sde can and will happen; it's likely that /dev/disk/by-id/<serial of "sda"> is symlinked to sde; What matters it the 'serial' or 'path' key in the structure.

I don;t think that's the issue here.

Adding the first partition (prep) is successful. Then when adding the second partition we fail, sgdisk says:

Could not create partition 2 from 18432 to 69300223

That's *usually* a miscalculation on sizes and offsets and total disk size.
Given that this is prep partitions, maybe we can recheck the values.

Total disk size:

283794997248B

The ending sector of the second partition, 69300223 * 4k is > than the total disk size.
This is what failed.

The offset 18432 looks odd; prep partition is 8MiB, the offset sent is 4MiB, though curtin only applied 1M offset (256.0). None-the less, the next start point should be
1M + 8M, or at most 4M + 8M , we can see the end sector of the prep partition is 2303 from the sgdisk command, so we should see:

2:2304.0:69284096.0

69284096.0 * 4096 = 283787657216.0

283787657216.0 > 283794997248
False

so, it fits.

Now, how did the second partition offset get so far off. curtin reads size and offset from /sys/class/block/<disk>/partition/{start, size}.

So, the questions now are:

1. did we read the correct path?

Yes, we've wiped all drives prior to creating new partitions, so no other disk will have partitions.
Then we see the message: previous partition number for 'sda-part2' found to be '1';
curtin has found /sys/class/block/sde/sde1, and will now read
/sys/class/block/sde/sde1/{size, start}

2. What values were in those fields.
curtin calculates the start of the new partition with:

offset_sectors = previous_start + previous_size

where previous_start is the value in /sys/class/block/sde/sde1/start and
previous_size is the value in /sys/class/block/sde/sde1/size