Not urban legend for us. We've experienced this just last week.
We have a new F810 with a dedicated GigE connection to an E880 (Sol8), intending to use the F810 as our mail spool device.
NFS mounting across UDP we can write to the NetApp at 60MB/s. Going from the NetApp to the SUN it goes at 25-30MB/s once or twice, and then slows right down to 1-2MB/s.
Mounting NFS across TCP, we see 50MB/s to the NetApp, and 25MB/s going back from the NetApp to the SUN.
With our production F740 mounting NFS/UDP across 100mb to our SUNs (Sol 2.6 and 8) we've had no performance problems.
-----Original Message----- As far as I'm concerned, this is an urban legend :-) I use UDP v3 on Solaris with NetApp, and I've always had a good performance, no worse than Linux or HPUX. When you say you experienced it yourself, what exactly did you see? Was it reproducible with iozone? What were the numbers? -----Original Message-----
In our environment, YMMV, Solaris (100mb) to NetApp (100mb) works fine over UDP. Solaris (100mb) to NetApp (gigabit) was horribly slow for certain operations. Normal file reads were fine, but a compare (`cmp`) of two files from the same filer were unbelievably slow. A cmp that would take 15 seconds to the 100mb interface of the NetApp would take an hour or more to the gigabit interface. To get Sun to actually admit it was their problem, we did a Solaris (100mb) to Solaris (gigabit) test over UDP, and it took 5minutes or so. Not as bad as to NetApp, but bad enough for them to file a bug, which Sun Engineering ignored since there is a work-around (use TCP or the 100mb interface of the filer). This was with Solaris 8. Solaris 7 did not have this problem in our environment.
Since nearly all our clients are 100mb, and only our QA group was running into this, we set their automount entries to point to the 100mb interface.
John