mhm

how bad of an idea it would be to use a NVMe stick so that half of it is "another side" of a pool and the rest is divided into four equal-sized parts used as SLOGs for other pools?

those other pools consist mostly of old hard drives

the question would be, what kind of load are you generating with sync mode writes?

because slog will get transaction group log writes on them, so you will have 4 pools pushing those logs on the single dev.

you can use zilstat to get some idea (assuming it is still usable with illumos)

this is just a file server at home. what I'm looking for is better performance when working with source code trees, build trees and the like, and figured this might help with them.

it isn't exactly slow now either, but I got the NVMe for next to nothing and figured I'll put it into the server.

no zilstat in OmniOS :(

man -k zil returns zilch, as the Americans say

well, unless you use zvols, nfs or apps like db systems, you probably have most IO done async. but, it would be good to check

everything happens over NFS and that's why I'm looking at this

nice, thank you

I somehow assumed it's an operating system command

"Google Drive can't scan this file for viruses." :D

it would be nice to have it (arcstat is there already)

can I somehow opt for an internet without training wheels

"probe description fbt::zil_lwb_write_start:entry does not match any probes" - hm. dtrace -ln 'fbt::zil*:entry' gives zil_lwb_write_open, zil_lwb_write_done and zil_lwb_write_issue. wonder which would be closer to the original intent - obviously not the "done" one but "open" or "issue"?

zil_lwb_write_issue() starts log block write.

zil_lwb_write_done() does issue DKIOCFLUSHWRITECACHE - that is, the write did land, but it may still be in the cache. zil_lwb_flush_vdevs_done() is telling the lwb is "done".

(from comments in zil.c)

DKIOCFLUSHWRITECACHE is the call which can kill the performance, as you will get them from 4 slog devices and from the data pool itself

thanks - good point, it's open source and this means that the source code can be read :) should've thought of that

but yeah, good point