On Fri, 13 Oct 2023 at 16:58, David Howells <dhowells@xxxxxxxxxx> wrote: > > (2) Use of fscache is not yet tested. I'm not sure whether to allow a > cache to be used with a write-through write. Just adding a quick end user "thumbs up" for this potential feature. We currently use fscache as the backend for "NFS re-export" servers to extend our onprem storage to remote cloud compute (which works great). But batch compute hosts (think VFX render farm) often chunk up stages of work into multiple batch jobs such that they read data, write results and then read the same data on different clients. Having the ability to also cache the recent writes closer to the compute clients (on the re-export server) would open up a lot of new workload possibilities for us. > (5) Write-through caching will generate and dispatch write subrequests as > it gathers enough data to hit wsize and has whole pages that at least > span that size. This needs to be a bit more flexible, allowing for a > filesystem such as CIFS to have a variable wsize. If I understand correctly, this is above and beyond the normal write back cache and is more in tune with the wsize (of NFS, CIFS etc) for each file? Again, our workloads are over longer latencies than are normal (NFS over 200ms!) so this sounds like a nice optimisation when dealing with slow stuttering file writes over high latency. I can definitely volunteer for some of the fscache + NFS testing. Cheers, Daire
