If we have three SSDs installed in a system, with a spare partition for the unused space on the SSD (
bcache be configured to use all three of those partitions to cache a single backing device (such as
/dev/md10 which is laid on top of
From what I have read elsewhere, it is possible that a particular SSD device can be used by
bcache to cache multiple hard drives or RAID arrays. But nothing explains whether a backing device can be cached by multiple SSDs at the same time.
For instance, you might have three 100GB SSDs instead of a single large 300GB SSD, and you want to use those as caching devices for a single 12TB array.