LBA format currently - reformat?

OpenZFS
1

When I run
nvme id-ns /dev/nvme0n1
I get
lbaf 0 : ms:0 lbads:9 rp:0 (in use)
There are no other LBA formats showing as optional.

I think when I originally set up my two devices (samsung 980 pro 1tb) I used a legacy utility to put a gpt partition on them which I think set the physical logical sector size to 512. I am thinking about re-setting up the devices by formatting to 4096 for better performance / wear & tear. I do have all pools set with ashift=12 which I think emulates the 4096, just not sure if it’s worth the trouble. Might I be better off reformatting?

My approach would be to first send the pools to another device that is properly formatted. Then reformat these and reset up to pools, to then receive back the data..

Appreciate any thoughts on it.

2

Probably not worth doing other than as a science experiment. In my experience NVMe drives do perform better with 512 byte sectors rather than 4KiB sectors, but the difference is subtle.

If you know ahead of time that you want to use that device in an a shift=12 pool, is it worth more level reformatting to 4KiB sectors? Probably.

Is it worth tearing down an existing NVMe pool to recreate it with ashift=12 and low level 4KiB sectors? Probably not, regardless of whether your existing ashift is 9 or 12. There is a measurable difference, but you have to be measuring–CAREFULLY–to see it.

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