Performance of Linux vs. FreeBSD NFS clients

[Josh Gentry]

I am seeing a dramatic difference in performance between Linux and FreeBSD servers mounting the FreeNAS server I have setup. I have searched the forums and not found a discussion of this as a general problem, so wonder what in my setup might be causing this.

The FreeNAS 8.3 server has a raidz2 pool of 5, 2TB disks, exported via NFS. I have that pool mounted on a FreeBSD 9.1 server, and a Gentoo server. If I just dd a large file to and from the NFS mounted zpool, I see almost identical performance. If I do an operation with many files, I see dramatically better performance from the FreeBSD server. I have primarily been using filebench, with the "webserver" template, to test. It creates 1000 small files, then creates several threads to read the files.

I have tried with and without an SSD cache disk, and with and without an SSD log disk. The discrepancy in performance is consistent. I have also tried with a different linux server, Debian instead of Gentoo, and different hardware. Discrepancy in performance is consistent. I have tested network throughput with iperf, and did not get any clues from that.

I tried autotune, with no noticeable difference.

More details on the FreeNAS server:
16 GB RAM
2 Xeon dual core 2.66GHz CPUs
LSILogic SAS/SATA Adapter
Rackable Systems SAS JBOD enclosure

Any help appreciated.

Thanks, Josh

 

[cyberjock]

Are you asking how to make Linux do disk transfers as fast as FreeBSD does?

 

[Josh Gentry]

How do I increases ops/s and reduce latency for the Linux servers? The FreeBSD performance really just points out that the Linux servers are under performing. Using the filebench test I described, I get these results from the Linux server: IO Summary: 509865 ops, 8497.197 ops/s, (2741/274 r/w), 42.6mb/s, 437us cpu/op, 31.3ms latency.

Same test with FreeBSD server gives these results: IO Summary: 2837091 ops, 47238.194 ops/s, (15238/1524 r/w), 250.5mb/s, 0us cpu/op, 5.8ms latency

Thanks.

 

[cyberjock]

I have no idea. This isn't a linux forum. You're kind of comparing apples to oranges and are upset that an apple isn't the same color as an orange. Each OS has its strengths and weaknesses. In this case, it looks like linux may not be as good as FreeBSD with file sharing or something related to file sharing.

I am going to move this to off-topic though since your question isn't geared at the FreeNAS box but the workstation itself.

I am curious to see if anyone responds. To be honest, I'm using Linux Mint on 3 of my machines and they far outperform Windows when it comes to file sharing. I'm somewhat surprised that there is room to improve further.

 

[aufalien]

Just to be clear; you are using Linux as an NFS client and/or a FreeBSD NFS client to a FreeNAS NFS server correct?

And you've noticed that a FreeBSD NFS client gets better results than a Linux NFS client?