[rhelv6-list] RHEL6.2 XFS brutal performence with lots of files

[Jussi Silvennoinen]

> I've been noticing lots of annoying problems with XFS performance with 
> RHEL6.2 on 64bit.  I typically have 20-30 TB file systems with data 
> structured in directories based on day of year, product type, for example,
>
>   /data/2012/06/05/product/blah.gif
>
> Doing operations like tar or rm over these directories bring the system to a 
> grinding halt.  Load average goes vertical and eventually the power button 
> needs to be pressed in many cases :( A hack workaround is to break apart the 
> task into smaller chunks and let the system breath in between operations...
>
> Anyway, I read Ric Wheeler's "Billion Files" with great interest
>
> http://www.redhat.com/summit/2011/presentations/summit/decoding_the_code/thursday/wheeler_t_0310_billion_files_2011.pdf
>
> It appears there are 'known issues' with XFS and RHEL6.1.  It does not appear 
> these issues were addressed in RHEL 6.2?
>
> Does anybody know if these issues were addressed in the upcoming RHEL 6.3? My 
> impression is that upstream fixes for this only recently (last 6 months?) 
> appeared in the mainline kernel.
>
> Perhaps I am missing some tuning that could be done to help with this?

Enabling lazy-count does wonders for workloads that involve massive 
amounts of metadata. Unfortunately it's a mkfs-time option only AFAIK.

-- 

   Jussi