MBall@datalink.com (Mike Ball) writes
I not sure I would be concerned about the 0's on disk writes you are seeing. As long as Net KB keeps coming in/out. The Netapp may be recalculating parity and holding the writes in NVRAM before it flushes to disk, etc..
He should be worried about there being too *few* 0's! As anyone who has done a "sysstat 1" (or just watched the pretty lights on the discs :-]) knows, ONTAP does disk writes in bursts (CPs). It will do a CP about once every 11 seconds unless NVRAM gets half-full (or some other exceptional condition happens) first.
Edward's CP's seem to be taking about 5-6 seconds each: that's definitely not normal. If he could do "sysstat -u" (presumably the reason he can't is that he is still on ONTAP 5.x), then he would see something like 50% in the "CP time" column. The cache age being stuck down at 1 minute all the time doesn't look healthy either.
It may be that the disc read traffic is what is making the CPs take so long. That's an effect I have observed during dumps when obviously there is a lot of read traffic, but the CP-expansion is not usually as extreme as in this case.
Chris Thompson University of Cambridge Computing Service, Email: cet1@ucs.cam.ac.uk New Museums Site, Cambridge CB2 3QH, Phone: +44 1223 334715 United Kingdom.