DOCUMENT ID: 1128-02 SYNOPSIS: Gathering Network Integrity Data From NFS OS RELEASE: PRODUCT: Solaris x86 KEYWORDS: network integrity data NFS DESCRIPTION: Using nfsstat to gather network integrity data from NFS. SOLUTION: Systems that are running NFS can get useful data about network corruption by using nfsstat -c, which reports the system's client- side NFS statistics (i.e., statistics about NFS requests that this system originated). Here's a typical report: Server rpc: calls badcalls nullrecv badlen xdrcall dupchecks dupreqs 0 0 0 0 0 0 0 Server nfs: calls badcalls 0 0 Version 2: (0 calls) null getattr setattr root lookup readlink read 0 0% 0 0% 0 0% 0 0% 0 0% 0 0% 0 0% wrcache write create remove rename link symlink 0 0% 0 0% 0 0% 0 0% 0 0% 0 0% 0 0% mkdir rmdir readdir statfs 0 0% 0 0% 0 0% 0 0% Client rpc: calls badcalls retrans badxids timeouts waits newcreds 75094 1 14 4 14 0 0 badverfs timers toobig nomem cantsend bufulocks 0 62 0 0 0 0 Client nfs: calls badcalls clgets cltoomany 73916 1 73916 0 Version 2: (73916 calls) null getattr setattr root lookup readlink read 0 0% 27493 37% 246 0% 0 0% 12494 16% 4 0% 18041 24% wrcache write create remove rename link symlink 0 0% 13696 18% 338 0% 313 0% 80 0% 3 0% 0 0% mkdir rmdir readdir statfs 11 0% 0 0% 505 0% 692 0% The retrans field (under Client rpc) indicates the number of packets that this host had to retransmit as an RPC client: that is, the number of retransmissions it made while reading or writing an NFS file. If this field is greater than 5 percent of the total number of client NFS calls, suspect trouble. Compare the number of retransmissions to the badxid field. If badxid and retrans are roughly equal, one or more of the network's NFS servers is having trouble keeping up with the client's demands. This isn't a data corruption problem, but a performance problem on the part of the server. If retrans is high but badxid is relatively small or zero, the problem is in the network itself - the network is either slow or suffering from data corruption. In this example, retransmissions are only about 0.3 percent of total number of RPC calls, an acceptably low figure. nfsstat can do one thing that netstat lacks: it lets you zero the counters at any time. Therefore, you don't have to have a look at data gathering over the last month - it's easy to collect data for day or so. To zero the counters, become root and give the command nfsstat -z. It may be useful to zero the nfsstat counters regularly. To zero the counters at 2 a.m. daily, add one of the following entries to your system's cron files: 0 2 * * * nfsstat -z # add to root crontab file. DATE APPROVED: 10/10/95