1 The following are demonstrations of the rfileio.d script. 2 3 4 rfileio.d prints file system statistics by file, 5 6 # ./rfileio.d 7 8 Read IOPS, top 20 (count) 9 /lib/ld.so.1 logical 2 10 /devices/pseudo/clone@0:ptm logical 4 11 /usr/bin/grep logical 4 12 /devices/pseudo/pts@0:3 logical 4 13 /extra1/contents physical 1700 14 /extra1/contents logical 11582 15 16 Read Bandwidth, top 20 (bytes) 17 /devices/pseudo/pts@0:3 logical 3 18 /devices/pseudo/clone@0:ptm logical 92 19 /lib/ld.so.1 logical 212 20 /usr/bin/grep logical 269 21 /extra1/contents physical 48115712 22 /extra1/contents logical 94865162 23 24 Total File System miss-rate: 50% 25 ^C 26 27 $ ls -l /extra1/contents 28 -rw-r--r-- 1 root root 94865162 Nov 2 21:08 /extra1/contents 29 30 The /extra1/contents file was read using the grep command. The output shows 31 that half of the contents was returned from the cache, the other half from disk 32 (50% miss-rate). It is 94,865,162 bytes in size, which can be seen both in 33 the ls -l output and the logical read() bytes reported by rfileio.d. There 34 were 11,582 logical read() calls, which the disk driver satisfied by using 35 1,700 disk events (aggregation). 36 37 38 39 The following demonstrates many files being read. 40 41 # ./rfileio.d 42 43 Read IOPS, top 20 (count) 44 /usr/bin/amd64/glib-mkenums logical 4 45 /usr/bin/amd64/glib-genmarshal physical 4 46 /usr/bin/amd64/gdk-pixbuf-query-loaders logical 4 47 /usr/bin/amd64/ls logical 5 48 /usr/bin/amd64/pargs logical 5 49 /usr/bin/amd64/ps logical 5 50 /usr/bin/amd64/gconf-merge-tree physical 6 51 /usr/bin/amd64/cputrack logical 6 52 /usr/bin/amd64/gconftool-2 physical 6 53 /usr/bin/amd64/prctl logical 6 54 /usr/bin/amd64/prstat logical 6 55 /usr/bin/amd64/glib-genmarshal logical 7 56 /usr/bin/amd64/truss physical 8 57 /usr/bin/amd64/sort logical 9 58 /usr/bin/amd64/prex logical 10 59 /usr/bin/amd64/gconf-merge-tree logical 13 60 /usr/bin/amd64/mdb physical 15 61 /usr/bin/amd64/gconftool-2 logical 15 62 /usr/bin/amd64/truss logical 26 63 /usr/bin/amd64/mdb logical 63 64 65 Read Bandwidth, top 20 (bytes) 66 /usr/bin/amd64/prctl logical 36784 67 /usr/bin/amd64/prctl physical 36864 68 /usr/bin/amd64/prstat logical 44760 69 /usr/bin/amd64/prstat physical 45056 70 /usr/bin/amd64/glib-genmarshal logical 46064 71 /usr/bin/amd64/glib-genmarshal physical 46080 72 /usr/bin/amd64/cputrack logical 46912 73 /usr/bin/amd64/cputrack physical 47104 74 /usr/bin/amd64/sort logical 65120 75 /usr/bin/amd64/sort physical 65536 76 /usr/bin/amd64/prex logical 80968 77 /usr/bin/amd64/prex physical 81920 78 /usr/bin/amd64/gconf-merge-tree logical 113592 79 /usr/bin/amd64/gconf-merge-tree physical 122880 80 /usr/bin/amd64/gconftool-2 logical 129208 81 /usr/bin/amd64/gconftool-2 physical 139264 82 /usr/bin/amd64/truss logical 246360 83 /usr/bin/amd64/truss physical 262144 84 /usr/bin/amd64/mdb logical 627456 85 /usr/bin/amd64/mdb physical 638976 86 87 Total File System miss-rate: 81% 88 ^C 89 90 The miss-rate was 81%, meaning we are returning around 20% of the data from 91 the cache. Details for the top 20 files read by-bytes and by-count are listed; 92 this shows the /usr/bin/amd64/mdb file was read() 63 times, causing 15 disk 93 reads, and while 627,456 bytes were requested, 638,976 bytes were read from 94 disk (the extra bytes are due to read-ahead and file system metadata). 95
Indexes created Fri Apr 24 00:22:58 UTC 2026