Raid 5 migration to bigger HDDs

[QNap_NAS1]

@dolbyman

make sure you have good backups, as … cache is prone to fail (even more so when used on single disks) and will result in reduced speeds (on QTS) due to bad destaging of dirty blocks.

I am using pure read-only cache, so I assume that will not increase risks for data in pool. Just for getting incorrect data from outside. Which is not so important in my case.