So I swapped my shiny SATA SSD for an even shinier PCI-E SSD. I run my core OS on the SSD because it's silly-fast. I did this on my old SSD so I created a new EXT4 partition and then just dded the data across (sorry I don't know the exact command I ran anymore) and after reinstalling grub, I booted onto the PCI-E SSD. At first glance everything had worked perfectly and things were running faster than ever.

But then I noticed the free disk space on the new, larger drive: it was almost exactly the same as it was on the other disk... A disk that was half its size.

So it looks as if I've copied the files across incorrectly and it's copied some of the filesystem metadata along with it.

Tools like du and Disk Usage Analyzer come back with the correct figures. Things that look at the partition (and not the files) seem to think the drive is 120GB

I've been using this drive for a week now so it's way out of sync with the old SSD so dumping the data and starting again isn't a job that fills me with joy but two questions:

1. Is there a way to fix my filesystem so it knows what it's really on about? fsck e2fsck and badblocks all seem to be able to scan it without finding a problem with it.

2. If I do plug my old SSD back in, copy the data off my PCI-E on to it and then copy it back onto a fresh filesystem (eg juggle the data around), what's the best way of doing that? I obviously want to keep all the permissions and softlinks where they are.