On 5/12/26 15:12, Dan McDonald wrote:
On May 12, 2026, at 4:44 PM, Lionel Cons <[email protected]>
wrote:

On Tue, 12 May 2026 at 19:43, Dan McDonald <[email protected]>
wrote:

On May 12, 2026, at 5:48 AM, Lionel Cons
<[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.

For a slog device, one critical parameter is how fast a SYNCHRONIZE
CACHE operation completes.  You want a device with a fast write cache
with power-loss protection (PLP); they have enough onboard power storage
in capacitors or supercaps that they can save the contents of the write
buffer when the power goes out..

Among the devices I have in hand, a couple old SATA ssds with PLP
outperform a couple M.2 NVMes lacking PLP by a factor of about 4.

If anyone's found decent small NVMe drives with PLP I want to hear
about it...

------------------------------------------
illumos: illumos-discuss
Permalink: 
https://illumos.topicbox.com/groups/discuss/T901128f742f38830-Mbeb06669b9d44947c53bcf18
Delivery options: https://illumos.topicbox.com/groups/discuss/subscription

Reply via email to