Re: Speed improvements in ZFS

Am 2023-08-16 18:48, schrieb Alexander Leidinger:
> Am 2023-08-15 23:29, schrieb Mateusz Guzik:
>> On 8/15/23, Alexander Leidinger <Alexander@leidinger.net> wrote:
>>> Am 2023-08-15 14:41, schrieb Mateusz Guzik:
>>> 
>>>> With this in mind can you provide: sysctl kern.maxvnodes
>>>> vfs.wantfreevnodes vfs.freevnodes vfs.vnodes_created vfs.numvnodes
>>>> vfs.recycles_free vfs.recycles
>>> 
>>> After a reboot:
>>> kern.maxvnodes: 10485760
>>> vfs.wantfreevnodes: 2621440
>>> vfs.freevnodes: 24696
>>> vfs.vnodes_created: 1658162
>>> vfs.numvnodes: 173937
>>> vfs.recycles_free: 0
>>> vfs.recycles: 0
> 
> New values after one rund of periodic:
> kern.maxvnodes: 10485760
> vfs.wantfreevnodes: 2621440
> vfs.freevnodes: 356202
> vfs.vnodes_created: 427696288
> vfs.numvnodes: 532620
> vfs.recycles_free: 20213257
> vfs.recycles: 0

And after the second round which only took 7h this night:
kern.maxvnodes: 10485760
vfs.wantfreevnodes: 2621440
vfs.freevnodes: 3071754
vfs.vnodes_created: 1275963316
vfs.numvnodes: 3414906
vfs.recycles_free: 58411371
vfs.recycles: 0

>>>> Meanwhile if there is tons of recycles, you can damage control by
>>>> bumping kern.maxvnodes.
> 
> What's the difference between recycles and recycles_free? Does the 
> above count as bumping the maxvnodes?

^^^^^

>>> Looks like there are not much free directly after the reboot. I will
>>> check the values tomorrow after the periodic run again and maybe
>>> increase by 10 or 100 so see if it makes a difference.
>>> 
>>>> If this is not the problem you can use dtrace to figure it out.
>>> 
>>> dtrace-count on vnlru_read_freevnodes() and vnlru_free_locked()? Or
>>> something else?
>>> 
>> 
>> I mean checking where find is spending time instead of speculating.
>> 
>> There is no productized way to do it so to speak, but the following
>> crapper should be good enough:
> [script]
> 
> I will let it run this night.

I have a 51MB text file, compressed to about 1MB. Are you interested to 
get it?

Bye,
Alexander.

-- 
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