Reduce size of VG and PV after removing LVs

Question

I have my laptop internal HDD where I will try to setup some raid so that I get some practice. I have this external HDD where I have already moved my home over and have already setup the mount points so that I get the external HDD copy of my home mounted when the computer starts and it is working.... now, my internal HDD has an LVM setup and I have already snuffed the home partition, which was setup in a LV eating up most of the room in the HDD. Now, I want to shrink the size of the VG/PV-Partition where it was setup so that I can then use the free space to get the RAID setup (and get my home back in the internal HDD).

I see a lot of articles around there about how to resize going up but I do not find anything relevant regarding shrinking out there after removing LVs. What would be the process involved to get this done?

Answer 1

If you really just want to practise using RAID configurations, I would recommend you don't touch your working system. Instead, use data files with loopback devices or small LV slices.

For worked examples see my answers to these questions,

• What should I expect to see if md/linux RAID is properly compensating for a failing drive
• Build RAID 5 with mdadm and 1 disk with data