Running SSD’s in RAID can get very expensive very quickly. A more cost effective solution is to have a disk RAID and use an SSD as a cache. I’m not sure if any of these are production ready but all are worth watching:
- zfs-fuse – supports the ZFS L2ARC feature which can be used to setup an SSD as a cache for a ZFS pool. Checksums SSD data and supports multiple devices.
- bcache – a recent project for caching linux block devices. Currently only supports 1 cache device and offers no checksumming.
- flashcache – created and released by and for facebook this at least seems to be in production. documentation is not great however.