Using sar I can see device nfss24 is very busy, but how to know which data volume (file system) the device is for?
sar -d 1 10|egrep "busy|nfs"
SunOS phxdbnfs11 5.10 Generic_141414-07 sun4v 04/14/2010
19:03:27 device %busy avque r+w/s blks/s avwait avserv
19:03:28 nfs23 0 0.0 0 0 0.0 0.0
nfs24 100 1484053.4 504 32123 2944300.0 47.5
nfs25 0 0.0 0 0 0.0 0.0
nfs26 0 0.0 0 0 0.0 0.0
nfs27 107 1.1 0 0 0.0 0.0
nfs28 107 17.0 0 0 0.0 0.0
nfs29 100 13109.5 460 29435 28451.7 52.0
nfs30 0 0.0 0 0 0.0 0.0
nfs31 107 9.6 0 0 0.0 0.0
nfs32 0 0.0 0 0 0.0 0.0
nfs33 107 1.1 0 0 0.0 0.0
19:03:29 nfs23 0 0.0 0 0 0.0 0.0
nfs24 100 1483762.8 530 33709 2797054.5 45.1
nfs25 0 0.0 0 0 0.0 0.0
nfs26 0 0.0 0 0 0.0 0.0
nfs27 107 1.1 0 0 0.0 0.0
nfs28 107 17.0 0 0 0.0 0.0
nfs29 100 12800.8 511 32732 25016.0 46.8
nfs30 0 0.0 0 0 0.0 0.0
nfs31 107 9.6 0 0 0.0 0.0
nfs32 0 0.0 0 0 0.0 0.0
nfs33 107 1.1 0 0 0.0 0.0
19:03:30 nfs23 0 0.0 0 0 0.0 0.0
nfs24 100 1483080.4 761 48162 1950073.8 31.4
nfs25 0 0.0 0 0 0.0 0.0
nfs26 0 0.0 0 0 0.0 0.0
nfs27 107 1.1 0 0 0.0 0.0
nfs28 107 17.0 0 0 0.0 0.0
nfs29 100 12406.7 737 46855 16800.7 32.4
nfs30 0 0.0 0 0 0.0 0.0
nfs31 107 9.6 0 0 0.0 0.0
nfs32 0 0.0 0 0 0.0 0.0
nfs33 107 1.1 0 0 0.0 0.0