I’d caution against using multiple disks for a storage node. The official advice is to run a second storage node instance with a new identity for each physical disk. (You can even run them on the same physical host easily using Docker.)
If you absolutely want to use multiple disks for a single node, RAID5 makes the most sense as only one disk is “wasted” providing redundancy.
RAID0 appears at first to be the most cost-effective approach, but each additional disk dramatically increases the risk of total volume failure. Any time a disk fails you would have to start over from scratch with a new identity and no data stored, and go through the vetting process again. RAID5 allows you to avoid that scenario at the cost of one disk’s worth of data. (Note that an LVM logical volume spread across multiple PVs has the same failure risk as a RAID0.)
But going back to my first point, running a node per physical disk has several advantages:
- You can fully utilize each disk, wasting no space for redundancy, which is already built-in to the network.
- If one disk fails, only that node is affected. The other nodes don’t lose their storage or escrow.
- You can use disks of different sizes without wasting space. (RAID uses the smallest PV size to determine the size of the array. LVM in linear mode can use multiple disks of different sizes but there is no redundancy in this mode.)