Calculate Linux disk bytes read/written based on sector size (512B)

Logical sector size appears to be fixed at 512B for the foreseeable
future in the kernel, so for now we just hard-code it.

1 files changed, 8 insertions, 0 deletions

diff --git a/collector/diskstats_linux_test.go b/collector/diskstats_linux_test.go
index 405bf28..21e5378 100644
--- a/collector/diskstats_linux_test.go
+++ b/collector/diskstats_linux_test.go
@@ -37,4 +37,12 @@ func TestDiskStats(t *testing.T) {
         if want, got := "68", diskStats["mmcblk0p2"][10]; want != got {
                 t.Errorf("want diskstats mmcblk0p2 %s, got %s", want, got)
         }
+
+        if want, got := "513713216512", diskStats["sda"][11]; want != got {
+                t.Errorf("want diskstats sda read bytes %s, got %s", want, got)
+        }
+
+        if want, got := "258916880384", diskStats["sda"][12]; want != got {
+                t.Errorf("want diskstats sda write bytes %s, got %s", want, got)
+        }
 }