zfs, a directory that used to hold lot of files and listing pause

[Dr. Nikolaus Klepp]

Am Donnerstag, 20. Oktober 2016 schrieb Eugene M. Zheganin:
> Hi.
> 
> I have FreeBSD 10.2-STABLE r289293 (but I have observed this situation 
> on different releases) and a zfs. I also have one directory that used to 
> have a lot of (tens of thousands) files. I surely takes a lot of time to 
> get a listing of it. But now I have 2 files and a couple of dozens 
> directories in it (I sorted files into directories). Surprisingly, 
> there's still a lag between "ls" and an output:
> 
> 
> ===Cut===
> 
> # /usr/bin/time -h ls
> .recycle        2016-01         2016-04         2016-07 2016-10         
> sort-files.sh
> 2014            2016-02         2016-05         2016-08 ktrace.out      
> sort-months.sh
> 2015            2016-03         2016-06         2016-09 old             
> sounds
>          5.75s real              0.00s user              0.02s sys
> 
> ===Cut===
> 
> 
> I've seen this situation before, on other servers, so it's not the first 
> time I encounter this. However, it's not 100% reproducible (I mean, if I 
> fill the directory with dozens of thousands of files, I will not 
> certainly get this lag after the deletion).
> 
> Has anyone seen this and does anyone know how to resolve this ? It's not 
> critical issue, but it makes thing uncomfortable here. One method I'm 
> aware of: you can move the contents of this directory to some other 
> place, then delete it and create again. But it's kind of a nasty workaround.


Hi!

I've the same issue, but only if the ZFS resides on a LSI MegaRaid and one RAID0 for each disk.

Nik


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