Hello, fans.
I’m running Plan 9(labs) on public QEMU/KVM service.
My Plan 9 system has a slow read performance problem.
I ran 'iostats md5sum /386/9pcf’, DMA is on, read result is 150KB/s.
but write performance is fast.
My Plan 9 system has a 200GB HDD, formatted with fossil+venti.
disk layout
The reason, in general:
In a fossil+venti setup, fossil runs (basically) as a
cache for venti. If your access just hits fossil, it’ll
be quick; if not, you hit the (significantly slower)
venti. I bet if you re-run the same test twice in a
row, you’re going to see dramatically improved
performance.
I'm experiencing the same issue as well.
When I launch vacfs on the same machine as Venti,
reading is very slow. When I launch vacfs on another
Plan 9 or Unix machine, reading is fast.
I've just made some measurements when reading a file:
Vacfs running on the same machine as Venti: 151 KB/s
