[lustre-discuss] Access times for file (file heat)

[Anna Fuchs]

Thank you.

Is there any documentation for the values?
Client-side means only statistics for the file remaining in the client 
cache? Not lifetime statistics?
Are there any plans to work further on this feature?

I think of several use cases when knowing these stats.
Cold data could be moved to archive like slow tape without relying on 
access time.
Hot blocks could be replicated or moved to faster caches and lot more 
optimizations.

Best regards
Anna



Am 18.02.2023 um 21:57 schrieb Andreas Dilger:
> Anna, there was a client-side file heat mechanism added a few years ago, but I don't know if it is fully functional today.
>
> lctl get_param llite.*.*heat*
> llite.myth-ffff979380fc1800.file_heat=1
> llite.myth-ffff979380fc1800.heat_decay_percentage=80
> llite.myth-ffff979380fc1800.heat_period_second=60
>
> And then "lfs heat_get <file>" to dump the file heat,  it there haven't been any good tools developed yet to list top heat files.
>
> Cheers, Andreas
>
>> On Feb 7, 2023, at 08:56, Anna Fuchs via lustre-discuss<lustre-discuss at lists.lustre.org>  wrote:
>>
>> Hello,
>>
>> is there a way to see how many times a file has been accessed ever (like a heat map)?
>>
>> Thanks
>> Anna
>>
>> -- 
>> Anna Fuchs
>> Universität Hamburg
>> https://wr.informatik.uni-hamburg.de
>>
>> anna.fuchs at informatik.uni-hamburg.de
>> https://wr.informatik.uni-hamburg.de/people/anna_fuchs
>>
>>
>>
>> _______________________________________________
>> lustre-discuss mailing list
>> lustre-discuss at lists.lustre.org
>> http://lists.lustre.org/listinfo.cgi/lustre-discuss-lustre.org

-- 
Anna Fuchs
Universität Hamburg
https://wr.informatik.uni-hamburg.de

anna.fuchs at informatik.uni-hamburg.de
https://wr.informatik.uni-hamburg.de/people/anna_fuchs
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