> On 15. May 2026, at 15:12, Surya prakki <[email protected]> wrote: > > Is the workload Read or Write intensive? If its read, whats the ARC cache hit > rate on the zfs side - if its not good, may be increasing ARC cache should > help; If its write, slog device helps as others already pointed out. > Is the problem being seen at certain times (hour of the day/day of the week) > or such? > Is the pool in general healthy? - no resilvering / failed drives !! > If all good on zfs side, is the client keeping enough OIO? b/w between the 2 > is decent and getting utilized fully? > I think a little more training is needed, I guess. > my 2c.
1. grab zilstat and check if/how many sync writes you have (and plan for slog or set sync=disabled). 2. one mount does create one connection, if the workload has multiple threads/processes, use more mountpoints... rgds, toomas > > On Wed, May 13, 2026 at 5:09 PM Lionel Cons <[email protected] > <mailto:[email protected]>> wrote: >> On Wed, 13 May 2026 at 00:12, Dan McDonald <[email protected] >> <mailto:[email protected]>> wrote: >> > >> > On May 12, 2026, at 4:44 PM, Lionel Cons <[email protected] >> > <mailto:[email protected]>> wrote: >> > > >> > > On Tue, 12 May 2026 at 19:43, Dan McDonald <[email protected] >> > > <mailto:[email protected]>> wrote: >> > >> >> > >> On May 12, 2026, at 5:48 AM, Lionel Cons <[email protected] >> > >> <mailto:[email protected]>> wrote: >> > >>> >> > >>> Are there suggestions on how to DRASTICALLY reduce Illumos nfsd I/O >> > >>> latency on ZFS? >> > >> >> > >> You're using a slog device on your pool, right? >> > > >> > > No, but I can try. Can slog devices be used for the root pool? Also, >> > > can slog devices be added and removes dynamically? >> > >> > Yes, and yes, respectively. HIGHLY recommend the lowest-latency device >> > you can get your hands on for a slog. Think "small but fast NVMe drive." >> >> Is there anything which can be done on the network and scheduler side? >> >> Linux has realtime scheduler classes, could this be done for the nfsd >> threads on Illumus too? Are there TCP6/IPv6 tuning parameters for >> improved latency? >> >> Lionel >> >> ------------------------------------------ >> illumos: illumos-zfs >> Permalink: >> https://illumos.topicbox.com/groups/zfs/T7c22b249653e43fb-Medd16ba86e5748e987f2e9be >> Delivery options: https://illumos.topicbox.com/groups/zfs/subscription > > illumos <https://illumos.topicbox.com/latest> / illumos-zfs / see discussions > <https://illumos.topicbox.com/groups/zfs> + participants > <https://illumos.topicbox.com/groups/zfs/members> + delivery options > <https://illumos.topicbox.com/groups/zfs/subscription>Permalink > <https://illumos.topicbox.com/groups/zfs/T7c22b249653e43fb-M129cf25301b34425a72d7e10> ------------------------------------------ illumos: illumos-discuss Permalink: https://illumos.topicbox.com/groups/discuss/T7c22b249653e43fb-Md6eee6d7b5a8b484abb525a6 Delivery options: https://illumos.topicbox.com/groups/discuss/subscription
