{"id":5372,"date":"2014-03-30T21:10:15","date_gmt":"2014-03-30T21:10:15","guid":{"rendered":"https:\/\/unknownerror.org\/index.php\/2014\/03\/30\/tuning-nfs-client-server-stack-collection-of-common-programming-errors\/"},"modified":"2014-03-30T21:10:15","modified_gmt":"2014-03-30T21:10:15","slug":"tuning-nfs-client-server-stack-collection-of-common-programming-errors","status":"publish","type":"post","link":"https:\/\/unknownerror.org\/index.php\/2014\/03\/30\/tuning-nfs-client-server-stack-collection-of-common-programming-errors\/","title":{"rendered":"Tuning NFS client\/server stack-Collection of common programming errors"},"content":{"rendered":"<p>For our RHEL\/CentOS 5 machines we use the following mount flags<\/p>\n<p>nfsvers=3,tcp,timeo=600,retrans=2,rsize=32768,wsize=32768,hard,intr,noatime<\/p>\n<p>Newer Linux kernel version support even larger rsize\/wsize parameters, but 32k is the maximum for the 2.6.18 kernel in EL5.<\/p>\n<p>On the NFS server(s), at least for Linux no_wdelay supposedly helps if you have a disk controller with BBWC. Also, if you use the noatime flag on the clients, it probably makes sense to mount the filesystems on the servers with noatime as well.<\/p>\n<p>And, as was already mentioned, don&#8217;t bother with UDP. With higher speed networks (1GbE+) there is a small, but non-zero, chance of a sequence number wraparound causing data corruption. Also, if there is a possibility of packet loss, TCP will perform better than UDP.<\/p>\n<p>If you&#8217;re not worrying about data integrity that much, the &#8220;async&#8221; export option can be a major performance improvement (the problem with async is that you might lose data if the server crashes).<\/p>\n<p>Also, at least for Linux server, you need to make sure you have enough NFS server threads running. The default 8 is just way too low.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>For our RHEL\/CentOS 5 machines we use the following mount flags nfsvers=3,tcp,timeo=600,retrans=2,rsize=32768,wsize=32768,hard,intr,noatime Newer Linux kernel version support even larger rsize\/wsize parameters, but 32k is the maximum for the 2.6.18 kernel in EL5. On the NFS server(s), at least for Linux no_wdelay supposedly helps if you have a disk controller with BBWC. Also, if you use [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-5372","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/posts\/5372","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/comments?post=5372"}],"version-history":[{"count":0,"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/posts\/5372\/revisions"}],"wp:attachment":[{"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/media?parent=5372"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/categories?post=5372"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/tags?post=5372"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}