On Feb 4, 2021, at 8:34 AM, Dan Cross <crossd(a)gmail.com> wrote:
On the other hand, if we're discussing OS design and implementation, (re)splitting
the VM and buffer caches is a poor decision. One might well ask, "why?" and the
answer may be, "because it adds significant complexity to the kernel." This to
me seems like the crux of the disagreement. Satisfied users of ZFS might legitimately ask,
"who cares?" and one might respond, "kernel maintainers." If the
kernel is mostly transparent as far as a particular use case goes, though, then I can see
why one would bulk at the suggestion that this matters. If one is concerned with the
design and implementation of kernels, I could see why one would care very much.
Largely agree; though the complexity battle has long been lost. On multiple fronts. Many
of us are happy to use such complex systems for their ease of use or their feature set but
wouldn’t want to maintain these systems!
I have used ZFS since 2005 and largely happy with it. Replaced all the disks twice. Moved
the same set of disks to a new machine. etc. Features: cheap and fast snapshots,
send/receive, clone, adding disks, checksummed blocks, redundancy etc. The dedup impl. is
suboptimal so I don't use it. No idea if they considered using a bloom filter and a
cache to reduce memory use. If a new FS came along with a similar set of features and a
simpler, better integrated implementation, I'd switch.