Replace Qnap System Disk

 If you have got yourself in a situation where qnap system volume is residing on a single SSD / HDD and you want to move to another single larger disk then there is no official way to do this - but its actually very easy.

step one - insert the new disk into a spare location on the NAS.

if your system volume is sde and the new disk is sdf then run the following command

dd if=/dev/sde of=/dev/sdf bs=100M 

If you are using entware on your NAS box - ( you really should be ) then you can 

opkg install pv

dd if=/dev/sde |pv | dd of=/dev/sdf bs=100M 

if you are cloning a 700G drive you can specify the size in pv

dd if=/dev/sde  |pv -s 700G | dd of=/dev/sdf bs=100M 

Will give you a nice status display:

25.9GiB 0:01:05 [ 384MiB/s] [========>                                                                                                                                                                                                                                                                                                                        ]  3% ETA 0:31:34

When this is done. shutdown the NAS

Remove the 2 drives that you've been working with.

startup the NAS again - the NAS will complain about the storage volume missing - re-insert the new bigger disk - the NAS will find it and will stop complaining about the volume and pool