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Bluestore is also more feature-rich: it has checksums, compression, erasure-coded overwrites and virtual clones. Checksums allow 2x-replicated pools self-heal better, erasure-coded overwrites make EC usable for RBD and CephFS, and virtual clones make VMs run faster after taking a snapshot.
Bluestore uses a lot more RAM, though, because it uses RocksDB for all metadata, additionally caches some of them by itself and also tries to cache some data blocks to compensate for the lack of page cache usage. The general rule of thumb is 1GB per 1TB of storage, but not less than 2GB in total.
And, suprisingly, there is one thing that may sometimes be worse with Bluestore: random write performance. The issue shows up in two popular setups.