On my ubuntu server, i have /dev/sda that has a single partition of /dev/sda1(30GB) and /dev/sdb that has a single partition of /dev/sdb1 (735GB). i installed bitcoin core on sda1 (default) and it started complaining of space today cos it regularly downloads the block chain. How do i install it on /dev/sdb1 since it is larger. I have to run these commands to install bitcoind
sudo apt-add-repository ppa:bitcoin/bitcoin
sudo apt-get update
sudo apt-get install bitcoind
If you do not want to move the entire system to the second disk, nor create LVM (which would probably require full system reinstall), I suggest, you examine the bitcoin packages and see where they install or keep data. Then you can copy/move the corresponding directory to a partition on a second disk and mount it with fstab.
OR you can create a new folder on second partition/HDD then create a link:
ln -s /path/to/newfolder/ ~/.bitcoin/blockchain folder
I was able to expand my sda1 partition to as much as 1TB. i went to my VM, stopped it, went to the disks menu, edited the disk size, saved it and restarted the VM.