On 7/15/25 5:24 AM, Daire Byrne wrote: > Just a quick note to say that we are one of the examples (batch render > farm) where we rely on the NFSD pagecache a lot. The new O_DIRECT style READs depend on the cache in the underlying block devices to keep READs fast. So, there is still some caching happening on the NFS server in this mode. > We have read heavy workloads where many clients share much of the same > input data (e.g. rendering sequential frames). > > In fact, our 2 x 100gbit servers have 3TB of RAM and serve 70% of all > reads from nfsd pagecache. It is not uncommon to max out the 200gbit > network in this way even with spinning rust storage. Can you tell us what persistent storage underlies your data sets? Are the hard drives in a hardware or software RAID, for example? Note that Mike's features are enabled via a debugfs switch -- this is because they are experimental for the moment. The default setting is to continue using the server's page cache. -- Chuck Lever
