well most often hba's and raid controllers are another thing which increases latency and makes maintenances costs go up quite a bit (more stuff to update) and also it's another part that can break.
that's why it's not recommended when running ceph.
that's why it's not recommended when running ceph.
But yes, hardware RAID controllers and ZFS don't go together.
You can build in redundancy at the component level, at the physical computer level, at the rack level, at the datacenter level, at the region level. Having all of them is almost certainly redundant and unnecessary at best.
[0] https://www.digitalocean.com/community/questions/poor-fsync-...
I'd rather have ZFS or something equivalent in software. Software can be inspected, is (hopefully) battle-tested for years by many different companies with different workloads & requirements, and worst-case scenario, because it's software, you can freeze the situation in time by taking byte-level snapshots of the underlying drives as well as a copy of the software for later examination/reverse-engineering, something you can't do with a hardware black box where you're bound to the physical hardware and often have a single shot at a recovery attempt (as it may change the state of the black box).
Have you heard of the SSD failures about a decade ago where the SSD controller's firmware had a bug that bricked the drive past a certain lifetime? The data is technically still there, and would be recoverable if you could bypass the controller or fix its firmware, but unless you had a very good relationship with the manufacturer of the SSD to gain access to the internal tools and/or source code to allow you to tinker with the controller you were SOL.