I have a different suggestion. Set up your target device with some sort of deduplication and/or compression. For example btrfs or zfs or vdo. Then you can clone to a file on the target, and hopefully you'll have space for the whole thing.
On Sat, Oct 26, 2019, 04:03 Shahrukh Merchant <shahr...@shahrukhmerchant.com> wrote: > I have a 500 GB HDD (source) that I want to clone to a 320 GB HDD > (destination). Both are MBR. Only about 60 GB of the source drive is > actually in use (in 2 partitions), the rest (400+ GB) is in unallocated > space. > > I will ask more specifically in two different ways: > > 1. I would like to tell ddrescue to clone the entire drive, i.e., > > ddrescue -f -n /dev/sda /dev/sdb > > BUT with options that effectively say "and don't worry if you run out of > space on the destination drive--just stop copying since the important > stuff is at the start anyway." Can I do that, and how? (And other than > relying on the Windows Disk Management visual to believe that the > unallocated space is all at the end, which it seems to be, is there some > other tool I can use to let me confirm that explicitly?) > > 2. If the answer to the above is "No" or "Not recommended," then I would > have to do the clone partition by partition. There are two partitions on > the source disk as follows: > > lsblk version > ------------- > sda 465.8G > -sda1 RECOVERY 9.8G ntfs > -sda1 OS 54.9G ntfs > > Windows 7 Disk Management version > --------------------------------- > Disk0 Basic/465.76 GB/Online > -------- > 9.77 GB > Healthy (Active, Recovery Partition) > -------- > OS (C:) > 54.93 GB (NTFS) > Healthy (Boot, Page File, Crash Dump, Primary Partition) > -------- > 401.07 GB > Unallocated > -------- > > So if I do the clone partition by partition, two things are not clear: > > (a) What is the sequence of commands I need to use (and how to I prepare > the destination drive in advance). Can I do, for example: > ddrescue -f -n /dev/sda1 /dev/sdb > ddrescue -f -n /dev/sda2 /dev/sdb > and have ddrescue figure out that I mean "put them in their > corresponding places on the destination drive based on how it was on the > source drive and fix the MFT so it does the right thing" (seems a lot to > ask for, but maybe it does!)? > > (b) How do I maintain the integrity of the destination drive w.r.t. the > MFT of that drive being properly configured (since it is not part of the > ddrescue copy, as I understand it, if I do a partition at a time), and > in terms of the destination drive booting fine in exactly the same way? > > Basically, the unallocated space at the end is the only part that I want > to be different, owing to the different in drive sizes. > > Thanks! > > Shahrukh > >