I really want to run ceph because it fits a number of criteria I have: gradually adding storage, mismatched disks, fault tolerance, erasure encoding, encryption, support out-of-the-box from other software (like Incus).
But then I look at the hardware suggestions, and they seem like an up-front investment and ongoing cost to keep at least three machines evenly matched on RAM and physical storage. I also want more of a single-box NAS.
Would it be idiotic to put a ceph setup all on one machine? I could run three mons on it with separate physical device backing each so I don’t lose everything from a disk failure with those. I’m not too concerned about speed or network partitioning, this would be lukewarm storage for me.
It has parity disks, which always need to be the largest disks in your array. You can run with either a single one double parity disk.
It seems to work well, as that’s how I’ve had to replace a dozen disks in the last year upgrading from 8tb disks to 18 or 22tb disks.