NFS Performance issue against NetApp

Thu May 2 23:43:23 UTC 2013

On 2013-05-02, at 15:18 , Graham Allan <allan at physics.umn.edu> wrote:

> On Thu, May 02, 2013 at 02:05:38PM -0700, Marc G. Fournier wrote:
>> 
>> The thing is, I'm not convinced it is a NFS related issue … there are *so* many other variables involved … it could be something with the network stack … it could be something with the scheduler … it could be … hell, it could be like the guy states in that blog posting (http://antibsd.wordpress.com/) and be the compiler changes … 
> 
> I'm just watching interestedly from the sidelines, and I hesitate to ask
> because it seems too obvious - maybe I missed something - but have you
> run both tests (Linux and FreeBSD) purely with local disk, to get a
> baseline independent of NFS?

Hadn't thought to do so with Linux, but …

Linux ……. 20732ms, 20117ms, 20935ms, 20130ms, 20560ms
FreeBSD .. 28996ms, 24794ms, 24702ms, 23311ms, 24153ms

In the case of the following, I umount the file system, change the settings, mount and then run two runs:

FreeBSD, nfs, vfs.nfs.prime_access_cache=1 …  279207ms, 273970ms
FreeBSD, nfs, vfs.nfs.prime_access_cache=0 … 279254ms, 274667ms
FreeBSD, oldnfs, vfs.nfs.prime_access_cache=0 … 244955ms, 243280ms
FreeBSD, oldnfs, vfs.nfs.prime_access_cache =1 … 242014ms, 242393ms

Default for vfs.nfs.prime_access_cache appears to be 0 …