Hi all, I'm migrating from Gentoo to CentOS... I'm experiencing a rather low performance in NFS r/w (as client). NFS server is solaris (which exports zfs volumes via nfs). The very same exports were mounted with the same parameters (auto,nosuid,exec) on gentoo and centos server (bot x86_64)... It happens that centos is 5-10 times slower either in read and write operations... Ok, I'll try to tune rsize and wsize, but does anybody have an hint on this low performance? Thanks d Davide Cittaro davide.cittaro at ifom-ieo-campus.it
On Wed, Dec 10, 2008 at 11:07 AM, Davide Cittaro <davide.cittaro at ifom-ieo-campus.it> wrote:> Hi all, I'm migrating from Gentoo to CentOS... I'm experiencing a > rather low performance in NFS r/w (as client). > NFS server is solaris (which exports zfs volumes via nfs). The very > same exports were mounted with the same parameters (auto,nosuid,exec) > on gentoo and centos server (bot x86_64)... It happens that centos is > 5-10 times slower either in read and write operations... Ok, I'll try > to tune rsize and wsize, but does anybody have an hint on this low > performance? >We've seen similar results, but only to specific types of servers. For example, we have an Onstor/XIV system that is showing 90MB/S throughput, but an acopia switch in front of it showing much degraded throughput. Have you tried these measurements against a native Linux NFS server? It might be a good data point to find out if this only happens against Solaris. However, it could be none of the above, and be degraded ZFS performance that the NFS protocol is exacerbating. Have you run network dumps? --Russell
Am Mittwoch, den 10.12.2008, 20:07 +0100 schrieb Davide Cittaro:> Hi all, I'm migrating from Gentoo to CentOS... I'm experiencing a > rather low performance in NFS r/w (as client).I am not the Linux Expert when it comes to the nfs implementation, but you should try two things: 1.) Nail Linux to use nfs v3 (imho mount option nfsvers=3) 2.) Use TCP, UDP Transmits are often slow these days. (mount option tcp)> NFS server is solaris (which exports zfs volumes via nfs). The very > same exports were mounted with the same parameters (auto,nosuid,exec) > on gentoo and centos server (bot x86_64)... It happens that centos is > 5-10 times slower either in read and write operations... Ok, I'll try > to tune rsize and wsize, but does anybody have an hint on this low > performance? >Maybe gentoo uses v3 per default. We have made great improvements at our site with these mount options. -- Stefan Held VI has only 2 Modes: obi unixkiste org The first one is for beeping all the time, FreeNode: foo_bar the second destroys the text. --------------------------------------------------------------------------- Fedora Ambassador: http://fedoraproject.org/wiki/StefanHeld --------------------------------------------------------------------------- perl -e'map{print pack c,($|++?1:13)+ord,select$,,$,,$,,$|}split//,ESEL.$/' ---------------------------------------------------------------------------
On Wed, Dec 10, 2008 at 12:07 PM, Davide Cittaro <davide.cittaro at ifom-ieo-campus.it> wrote:> Hi all, I'm migrating from Gentoo to CentOS... I'm experiencing a > rather low performance in NFS r/w (as client). > NFS server is solaris (which exports zfs volumes via nfs). The very > same exports were mounted with the same parameters (auto,nosuid,exec) > on gentoo and centos server (bot x86_64)... It happens that centos is > 5-10 times slower either in read and write operations... Ok, I'll try > to tune rsize and wsize, but does anybody have an hint on this low > performance? >Which version of CentOS are you using? The upstream kernels have had issues at different points with NFS performance (the 2.6.18 had a bunch of problems that were fixed in 2.6.20-22 time frame and have had to be backported.. then there were changes and breakage somewhere after that.. ) I normally try a set of comparisons: 1) What does CentOS-4 do? What does CentOS-5 do? 4 may actually be faster than 5 in some cases due to switch/card issues. 2) Then there are issues with TCP, size of frames, etc... -- Stephen J Smoogen. -- BSD/GNU/Linux How far that little candle throws his beams! So shines a good deed in a naughty world. = Shakespeare. "The Merchant of Venice"