On 04/08/10 03:53, Craig Ringer wrote:
> BTW, When I suggested that greater write concurrency would be desirable
> and should be easier, Phil Stracchino raised some concerns about
> concurrent writes to a file system increasing fragmentation and hurting
> overall performance. Rather than just wave my hands about that I've put
> together a testing tool for concurrently writing big files from multiple
> threads that optionally uses posix_fallocate to pre-allocate ahead in
> chunks up to total file size. It tracks per-thread and total runtime and
> time spent in write() and posix_fallocate() calls. I'm doing some tests
> with it now and will post it to the bacula-devel list too. I'm planning
> on testing the real effects of various levels of concurrent writes on
> common file systems with it using a controlling shell script and will
> report back when that eventually finishes.

I'll be interested to see those results.  Which filesystems are you testing?

-- 
  Phil Stracchino, CDK#2     DoD#299792458     ICBM: 43.5607, -71.355
  alaric AT caerllewys DOT net   alaric AT metrocast DOT net   phil AT 
co.ordinate DOT org
         Renaissance Man, Unix ronin, Perl hacker, Free Stater
                 It's not the years, it's the mileage.

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