Sorry for the dupe post -- got no traction in Hardware & Laptops, so I thought maybe that was the wrong place.
I have a new laptop, windows pre-installed (of course they used the whole partition table, so I had to figure out which ones I could delete, grr). Anyway I repartitioned it before finding out about the 4096 blocksize issue. Fortunately I haven't gone crazy yet -- I have sda1 and sda2 for Windows (sda2 is the main Windows partition), sda3 for Linux root, sda4 extended, sda5 is /home, and sda6 is swap.
Sda1 and sda2 have sizes that are multiples of 4096, but sda3 does not, so the extended partition does not start on a physical block.
Is there any way to non-destructively move the start point of the extended partition? I'm guessing not, but just in case. If I have to delete the extended, that's not too bad, because I don't have much on /home yet, which is the only non-swap partition in there.
Assuming I do have to delete the extended partition, (1) how do I make it start on a multiple of 4096, and (2) how do I recreate my user home directory, with a home directory in /home and all the defaults? (Using ecryptfs, if that makes a difference.)